Fishes

36 pages, 6672 KB

Open AccessEditor’s ChoiceReview

How May the Increase in Pink Salmon (Oncorhynchus gorbucsha) Cause the Populations of the Atlantic Salmon (Salmo salar) to Decline?

by Marja Keinänen and Pekka J. Vuorinen

Fishes 2026, 11(1), 17; https://doi.org/10.3390/fishes11010017 - 27 Dec 2025

Viewed by 1002

Abstract

Atlantic salmon (Salmo salar) populations in the Arctic River Teno (Tana) and other North Atlantic rivers have declined at the same time as pink salmon (Oncorhynchus gorbuscha) have begun to spawn extensively in these rivers in odd-numbered years. In [...] Read more.

Atlantic salmon (Salmo salar) populations in the Arctic River Teno (Tana) and other North Atlantic rivers have declined at the same time as pink salmon (Oncorhynchus gorbuscha) have begun to spawn extensively in these rivers in odd-numbered years. In the River Teno, especially, the number of one-sea-year Atlantic salmon ascendants has decreased. In this short review, we assess, based on current information, how the abundance of pink salmon may weaken the survival of Atlantic salmon. Our hypothesis is based on recent evidence from Atlantic salmon in the Baltic Sea showing that the high marine lipid content in the diet of Atlantic salmon post-smolts impairs their growth and survival and is manifested in low numbers of ascendants and in poor thiamine (vitamin B1) status in both juvenile and spawning Baltic salmon. The high energy density of lipids increases the need for thiamine in the metabolism, and the high content of highly unsaturated fatty acids (n–3 HUFAs), like docosahexaenoic acid (DHA, 22:6n–3), in marine fish lipids increases the rate of lipid peroxidation, which consumes thiamine as it acts as an antioxidant against lipid peroxidation. The review presents information that could be used in planning possible future research on the topic. Full article

(This article belongs to the Section Biology and Ecology)

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17 pages, 1378 KB

Open AccessEditor’s ChoiceArticle

Extremely Low Sample Size Allows Age and Growth Estimation in a Rare and Threatened Shark

by Peter M. Kyne, Jonathan J. Smart and Grant J. Johnson

Fishes 2026, 11(1), 7; https://doi.org/10.3390/fishes11010007 - 24 Dec 2025

Viewed by 436

Abstract

Understanding life history parameters is key to assessing demography, biological productivity, and extinction risk of fishes. Age and growth analyses in chondrichthyan fishes (sharks, rays, and ghost sharks) is primarily undertaken through counting vertebral band pairs. For rare, threatened, and protected species such [...] Read more.

Understanding life history parameters is key to assessing demography, biological productivity, and extinction risk of fishes. Age and growth analyses in chondrichthyan fishes (sharks, rays, and ghost sharks) is primarily undertaken through counting vertebral band pairs. For rare, threatened, and protected species such as river sharks (Carcharhinidae; Glyphis), obtaining sufficient vertebrae samples may not be possible. Here we use a very small sample size, selective size-class sampling, back-calculation techniques, and a Bayesian hierarchical model that accounts for repeated measures to provide age and growth information for the Speartooth Shark Glyphis glyphis from which comprehensive sampling is not possible. Ten individuals were selectively sampled from the Adelaide River, Northern Territory, Australia. Bayesian length-at-age models using a combination of informative and uninformative priors in a multi-model framework were applied to the observed and back-calculated data with the sexes combined. Band pair counts produced age estimates of 0–11 years and suggest that age at maturity is possibly >12 years. Most model parameter estimates for length-at-birth (L₀) and asymptotic length (L_∞) were biologically plausible. The Gompertz growth function, applied through a Bayesian hierarchical approach to back-calculated data, provided the best fitting and most biologically appropriate length-at-age parameters: L_∞ = 229.5 cm TL ± (14.6 SE), g_Gom = 0.16 yr⁻¹ ± (0.01 SE), and L₀ = 58.2 cm TL ± (1.4 SE). The results presented here are the first study to apply Bayesian methods to back-calculated length-at-age data while accounting for repeated measures. Full article

(This article belongs to the Special Issue Biology and Conservation of Elasmobranchs)

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41 pages, 1516 KB

Open AccessEditor’s ChoiceReview

Exploring NAD⁺ Biology in Fish: From Cellular Metabolism to Ecological Adaptations and Aquaculture Strategies

by María Ángeles Esteban and Álvaro Sánchez-Ferrer

Fishes 2025, 10(12), 647; https://doi.org/10.3390/fishes10120647 - 15 Dec 2025

Viewed by 841

Abstract

This review elucidates the foundational principles of nicotinamide adenine dinucleotide (NAD⁺) homeostasis in humans, emphasizing its depletion during aging and in age-associated disorders. Subsequently, the discussion extends to NAD⁺ precursors and their potential therapeutic applications, with insights from research using [...] Read more.

This review elucidates the foundational principles of nicotinamide adenine dinucleotide (NAD⁺) homeostasis in humans, emphasizing its depletion during aging and in age-associated disorders. Subsequently, the discussion extends to NAD⁺ precursors and their potential therapeutic applications, with insights from research using zebrafish as a disease model. This information sheds light on the growing interest in NAD and its metabolism in the medical field and sparks curiosity among researchers focused on fish studies. The review further explores the role of nicotinamide in fish, encompassing core NAD⁺ metabolism, its participation in oxidative stress, environmental challenges, and the mitigation of pollutant-induced toxicity. Additionally, the implications of NAD⁺ in fish neurobiology, immune regulation, host–pathogen interactions, skin, eggs, and post mortem muscle were considered. Dietary modulation of NAD⁺ pathways to enhance growth, immunity, and product quality in aquaculture has also been highlighted. This review highlights the significance of NAD⁺ metabolism in fish biology, covering cellular energy production, physiological processes, and environmental adaptation, and proposes targeting NAD⁺-related pathways as a strategy for aquaculture and fish health management. Full article

(This article belongs to the Special Issue Feature Papers by Fishes’ Editorial Board Members)

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15 pages, 1740 KB

Open AccessEditor’s ChoiceArticle

Spatiotemporal and Environmental Effects on Demersal Fishes Along the Nearshore Texas Continental Shelf

by Erin M. Johnson, Fernando Martinez-Andrade, P. Santiago Domínguez-Sánchez, Aurora Gaona-Hernandez, Chengxue Li and R. J. David Wells

Fishes 2025, 10(12), 632; https://doi.org/10.3390/fishes10120632 - 9 Dec 2025

Viewed by 606

Abstract

The goal of this study was to analyze data from a 10-year bottom longline survey to examine spatial, temporal, and environmental effects on demersal fishes along the Texas coast within the northwestern Gulf of Mexico. Generalized additive models (GAMs) and generalized linear models [...] Read more.

The goal of this study was to analyze data from a 10-year bottom longline survey to examine spatial, temporal, and environmental effects on demersal fishes along the Texas coast within the northwestern Gulf of Mexico. Generalized additive models (GAMs) and generalized linear models (GLMs) were employed to evaluate trends and patterns in species composition (species richness and species diversity), relative abundance, and presence probability of fish species in the Texas region of the northwestern Gulf of Mexico. Temperature, salinity, and dissolved oxygen were the most influential variables driving richness, diversity, and abundance of demersal fish assemblages. The community was dominated by six species that represent 93% of total catch: Rhizoprionodon terraenovae (Atlantic sharpnose shark), Bagre marinus (gafftopsail catfish), Sciaenops ocellatus (red drum), Carcharhinus limbatus (blacktip shark), Carcharhinus brevipinna (spinner shark), and Carcharhinus leucas (bull shark). Analyses of dominant species revealed that multiple factors modulated their presence probability, with temperature and dissolved oxygen as common environmental drivers among species. Findings from the present study suggest that the composition and abundance of demersal fish assemblages were shaped by key environmental drivers. Full article

(This article belongs to the Section Biology and Ecology)

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23 pages, 6175 KB

Open AccessEditor’s ChoiceArticle

Danger! Stay Alert: The Role of Skein Cells in the Evolution of the Sea Lamprey (Petromyzon marinus, Linnaeus 1758)

by Alessio Alesci, Sebastian Marino, Stefania Fiorentino, Anthea Miller, Simon Palato, Sergio Famulari, Giorgia Pia Lombardo, Roberto Ferreira Artoni and Eugenia Rita Lauriano

Fishes 2025, 10(12), 605; https://doi.org/10.3390/fishes10120605 - 26 Nov 2025

Viewed by 567

Abstract

When it comes to predation, alarm signals enable individuals to assess risks and modulate their behavior accordingly. These signals, often chemical in aquatic environments, can be recognized across species boundaries and are typically released through injury-induced mechanisms in response to predation. While extensively [...] Read more.

When it comes to predation, alarm signals enable individuals to assess risks and modulate their behavior accordingly. These signals, often chemical in aquatic environments, can be recognized across species boundaries and are typically released through injury-induced mechanisms in response to predation. While extensively documented in teleosts, particularly those possessing epidermal club cells, such mechanisms remain poorly understood in more basal vertebrates, such as lampreys, which possess unique epidermal structures called skein cells. The present study investigated the potential role of skein cells in the immune and alarm signaling systems of the sea lamprey (Petromyzon marinus), given their strategic location in the skin and distinctive ultrastructural characteristics, such as polarized nuclei and tonofilament-rich basal cytoplasm. Although originally misidentified as club cells, skein cells may be involved in mucus secretion and the release of compounds such as sialic acid and glycoconjugates, which provide defense against aquatic pathogens. This study employed histomorphological analysis, immunoperoxidase labeling, confocal microscopy, bioinformatics, and quantitative and statistical analysis to investigate the hypothesis that skein cells contribute to anti-predator defense via the release of alarm substances. These findings provide new insights into the evolutionary origins and functional diversity of chemical signaling in the early vertebrate. Full article

(This article belongs to the Section Biology and Ecology)

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23 pages, 10985 KB

Open AccessEditor’s ChoiceArticle

Comparative Physiological Profiling of Abalone (Haliotis iris): Insights from Wild and Aquaculture Broodstock

by Ruchira S. Sawant, Leonie Venter, Awanis Azizan, Jinchen Guo, Jack Carter, Natalia Bullon, Tony Chen, Joanna S. Copedo, Norman L. C. Ragg, Armagan Sabetian and Andrea C. Alfaro

Fishes 2025, 10(11), 566; https://doi.org/10.3390/fishes10110566 - 5 Nov 2025

Viewed by 1079

Abstract

New Zealand abalone (Haliotis iris) holds ecological, economic, and cultural value, with wild stocks supporting fisheries and an emerging aquaculture industry. Wild-caught adult abalone are often used as broodstock, but captivity can affect spawning and offspring quality. This study is the [...] Read more.

New Zealand abalone (Haliotis iris) holds ecological, economic, and cultural value, with wild stocks supporting fisheries and an emerging aquaculture industry. Wild-caught adult abalone are often used as broodstock, but captivity can affect spawning and offspring quality. This study is the first to profile wild and farmed H. iris broodstock using histology, proximate composition, microbiome, and metabolomics analyses. Histology showed higher gonadal abnormalities in farmed abalone, while wild abalone exhibited increased ciliates in their gills, indicating richer marine–microorganism interactions. Microbiome analyses revealed a higher microbial richness and diversity in the buccal cavity of wild abalone. The core microbiota phyla across both groups included Proteobacteria, Bacteroidota, Campylobacterota, Fusobacteria, and Firmicutes. Proximate analyses showed higher muscle protein in farmed abalone, while gonadal tissue partitioned by sex showed higher fat in females and higher protein in males. Metabolomics revealed altered amino acid metabolism in the adductor muscle, carboxylic acid metabolism in the gonad, and fatty acid metabolism in the foot. This investigation expands our understanding of the physiological and microbial differences between wild and farmed abalone, showing altered gonad and muscle conditions from prolonged captivity and highlighting the need for greater microbial diversity in cultured stocks. Full article

(This article belongs to the Section Physiology and Biochemistry)

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17 pages, 1438 KB

Open AccessEditor’s ChoiceArticle

Impact of Stocking Density on Growth, Feeding Behavior, and Flesh Quality of Largemouth Bass (Micropterus salmoides) in Coupled Aquaponic Systems

by Marco Birolo, Veronica Trabacchin, Paolo Sambo, Stefano Triolone and Carlo Nicoletto

Fishes 2025, 10(11), 552; https://doi.org/10.3390/fishes10110552 - 2 Nov 2025

Viewed by 1656

Abstract

Stocking density is a key driver of performance in aquaponics, affecting both fish welfare and crop yield. This study evaluated the impact of three initial stocking densities (3.1, 4.1, and 6.2 kg/m³) on survival, growth, feeding behavior, carcass and filet quality [...] Read more.

Stocking density is a key driver of performance in aquaponics, affecting both fish welfare and crop yield. This study evaluated the impact of three initial stocking densities (3.1, 4.1, and 6.2 kg/m³) on survival, growth, feeding behavior, carcass and filet quality of largemouth bass (Micropterus salmoides), as well as on the yield of lettuce (Lactuca sativa), sweet basil (Ocimum basilicum), and Swiss chard (Beta vulgaris var. cicla) cultivated in vertical coupled aquaponic units. A total of 184 fish (109 ± 28 g) were reared for 176 days in nine independent recirculating systems. Fish reared at the lowest density achieved the highest final live weight and specific growth rate, with a better feed conversion ratio, whereas performance declined at higher densities despite similar survival rates. Feeding behavior was generally consistent across groups, although feed intake rate was reduced at the highest density. Carcass and filet quality traits were unaffected by stocking density. Vegetable yield was enhanced by higher fish biomass, with significant increases in lettuce production and a positive trend for basil. These findings indicate that intermediate stocking densities may represent the most sustainable compromise, ensuring fish welfare and acceptable growth while supporting efficient plant production in largemouth bass–based aquaponics. Full article

(This article belongs to the Special Issue Fish Health and Welfare in Aquaculture and Research Settings)

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15 pages, 254 KB

Open AccessEditor’s ChoiceArticle

Comparative Effects of Arthrobacter bussei-Derived Powder and Probiotics, and Haematococcus pluvialis Powder, as Dietary Supplements for Pacific White Shrimp (Litopenaeus vannamei)

by Soohwan Kim, Hyun Mi Jung, Seunghan Lee and Hyon-Sob Han

Fishes 2025, 10(11), 543; https://doi.org/10.3390/fishes10110543 - 24 Oct 2025

Viewed by 625

Abstract

This study evaluated how dietary supplementation with Haematococcus pluvialis powder (HPP), Arthrobacter bussei powder (ABP), and A. bussei probiotics affects growth, whole-body composition, non-specific immunity, antioxidant capacity, and nutrient digestibility in Pacific white shrimp (Litopenaeus vannamei). Juvenile shrimps were fed for [...] Read more.

This study evaluated how dietary supplementation with Haematococcus pluvialis powder (HPP), Arthrobacter bussei powder (ABP), and A. bussei probiotics affects growth, whole-body composition, non-specific immunity, antioxidant capacity, and nutrient digestibility in Pacific white shrimp (Litopenaeus vannamei). Juvenile shrimps were fed for 8 weeks with five diets: a control diet (CON), H. pluvialis powder (HPP, 1%), A. bussei powder (ABP, 1%), or A. bussei probiotics at 10⁵ (ABL) or 10⁸ (ABH) CFU g⁻¹ feed. Shrimp fed the ABP diet exhibited the highest final body weight, weight gain, and protein efficiency ratio, with a significantly improved feed conversion ratio than that of CON, ABL, and ABH groups. The HPP group exhibited significantly better growth than that of the control. Regarding immunity and antioxidant responses, lysozyme and phenoloxidase specific activities, as well as glutathione peroxidase and superoxide dismutase specific activities, were significantly enhanced in shrimp fed ABP and HPP diets, whereas malondialdehyde levels were significantly reduced compared with those in CON. Apparent crude protein digestibility was significantly higher in all supplemented diets than those in the CON group, with ABP showing the highest value. ABP and HPP supplementation improved growth, protein digestibility, and immune-antioxidant responses in L. vannamei, whereas probiotic forms showed limited effects. ABP is a superior functional feed additive than its probiotic form for enhancing productivity and health in shrimp aquaculture. Full article

(This article belongs to the Section Nutrition and Feeding)

14 pages, 1723 KB

Open AccessEditor’s ChoiceArticle

High Connectivity in the Deep-Water Pagellus bogaraveo: Phylogeographic Assessment Across Mediterranean and Atlantic Waters

by Martina Spiga, Giusy Catalano, Federica Piattoni, Alice Ferrari, Carolina Johnstone, Kenza Mokhtar-Jamaï, Montse Pérez, Fabio Fiorentino, Manuel Hidalgo and Alessia Cariani

Fishes 2025, 10(10), 527; https://doi.org/10.3390/fishes10100527 - 17 Oct 2025

Viewed by 650

Abstract

The Blackspot Seabream, Pagellus bogaraveo, is a commercially valuable species widely distributed in the northeastern Atlantic and Mediterranean. Its biology makes it vulnerable to overfishing, but its population structure and ontogenetic migration strategy remain unclear. Building on previous work based on microsatellite [...] Read more.

The Blackspot Seabream, Pagellus bogaraveo, is a commercially valuable species widely distributed in the northeastern Atlantic and Mediterranean. Its biology makes it vulnerable to overfishing, but its population structure and ontogenetic migration strategy remain unclear. Building on previous work based on microsatellite markers, we expanded the investigation by analysing the mitochondrial Control Region (CR) to complement nuclear data. We analysed 199 specimens from 13 sites and combined the new CR sequences with 129 published records to achieve the broadest coverage in terms of biogeographic and genetic data. We calculated genetic diversity and performed AMOVA, pairwise ΦST comparisons, and multivariate analyses. Eighty-eight haplotypes were identified, showing high haplotype diversity (Hd = 0.767–0.945) and moderate nucleotide diversity (π = 0.0026–0.0054). Most genetic variation occurred within populations, and overall analyses indicated genetic homogeneity. However, pairwise analysis and AMOVA confirmed significant differentiation of the Azores population. These results confirm extensive genetic connectivity throughout the Atlantic–Mediterranean range of P. bogaraveo, likely due to a combination of large larval dispersal and a common spawning migration strategy, but identify the Azores as a genetically distinct unit. This highlights the need to consider both large-scale connectivity and local divergence in fisheries management. Full article

(This article belongs to the Special Issue Conservation and Population Genetics of Fishes)

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18 pages, 1665 KB

Open AccessEditor’s ChoiceArticle

Anthropogenic Microparticles in Aquaculture and Wild Fish: A Case Study of Three Commercially Important Species in the Eastern Mediterranean

by Aikaterini Kostoula, Eugenia Moschou-Kounopioti, Niki Milatou and Persefoni Megalofonou

Fishes 2025, 10(10), 492; https://doi.org/10.3390/fishes10100492 - 2 Oct 2025

Viewed by 639

Abstract

Over the past decade, increasing attention has been given to the impacts of anthropogenic microparticle (AM) pollution on marine ecosystems. This study investigates AM ingestion in three commercially important fish species—Sparus aurata Linnaeus, 1758, Dicentrarchus labrax Linnaeus, 1758, and Boops boops Linnaeus, [...] Read more.

Over the past decade, increasing attention has been given to the impacts of anthropogenic microparticle (AM) pollution on marine ecosystems. This study investigates AM ingestion in three commercially important fish species—Sparus aurata Linnaeus, 1758, Dicentrarchus labrax Linnaeus, 1758, and Boops boops Linnaeus, 1758—collected from both wild and farmed populations in Greek marine and lagoon environments. A total of 60 specimens were sampled from the Messolonghi Lagoon, Rhodes Island, and the Cyclades. AM were detected in 61.7% of the individuals analyzed. The mean number of ingested items per individual was 1.1 ± 1.2 in B. boops, 1.0 ± 1.7 in wild and 2.3 ± 2.1 in farmed S. aurata, and 2.5 ± 3.1 in wild and 3.6 ± 2.2 in farmed D. labrax. Ingestion ranged from 0 to 9 items per fish. No significant correlations were found between fish size and either the number or the size of ingested AM in any species. The ingested AM were primarily classified as fibers and fragments, displaying variability in size and color. Black was the dominant color across all species, followed by red and blue, while yellow was rarely observed. A statistically significant difference in the mean size of AM was recorded between wild and farmed D. labrax, whereas no such difference was observed for S. aurata. Overall, these findings provide new evidence on AM contamination in seafood species and highlight their occurrence in both natural and aquaculture environments of the eastern Mediterranean. Full article

(This article belongs to the Section Biology and Ecology)

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15 pages, 478 KB

Open AccessEditor’s ChoiceArticle

Nitrogen Budget in Yellow-Tail Lambari Monoculture and Integrated Aquaculture

by Dalton Belmudes, Andre Z. Boaratti, Paulo V. L. Mantoan, Aline M. Marques, Julia R. C. Ferreira, Patricia Moraes-Valenti, Dallas L. Flickinger and Wagner C. Valenti

Fishes 2025, 10(10), 480; https://doi.org/10.3390/fishes10100480 - 26 Sep 2025

Cited by 2 | Viewed by 715

Abstract

This study quantified nitrogen (N) inputs by water, feed, animals, and atmospheric gas and outputs by water, harvested animals, sediments, and gas emissions in earthen ponds used for the monoculture and integrated cultures of yellow-tail lambari (Astyanax lacustris), Amazon River prawn [...] Read more.

This study quantified nitrogen (N) inputs by water, feed, animals, and atmospheric gas and outputs by water, harvested animals, sediments, and gas emissions in earthen ponds used for the monoculture and integrated cultures of yellow-tail lambari (Astyanax lacustris), Amazon River prawn (Macrobrachium amazonicum), and curimbata (Prochilodus lineatus), and evaluated whether epibenthic species improve N retention in harvested biomass. Three systems with four replicates were tested, lambari monoculture (L), lambari–prawn (LP), and lambari–prawn–curimbata (LPC), stocked at 50, 25, and 13 individuals m⁻², respectively. Feed N was the major input (67–75%), followed by inlet water (19–30%). Harvested biomass represented 20–23% of total outputs, sediments 25–33%, and gaseous emissions 7–29%, while outlet water contributed <3%. N lost through seepage was highest in L (70.5 ± 22.9 kg N ha⁻¹). N₂ ebullition increased with benthic species, from 10.4 ± 10.6 kg N ha⁻¹ (L) to 72.1 ± 32.4 kg N ha⁻¹ (LPC). N recovered in lambari was 43.2 ± 7.4 kg N ha⁻¹ in LPC, 36 ± 8.6 in L, and 33 ± 5.6 in LP. Considering all species, recovery of dietary N increased from 20.0 ± 4.3% (L) to 35.0 ± 5.9% (LPC), and recovery from all inputs rose from 13.0 ± 2.2% to 18.0 ± 3.4%. Integrated systems, particularly LPC, enhanced N retention in biomass and reduced environmental losses. Full article

(This article belongs to the Special Issue Integrated Multi-Trophic Aquaculture (IMTA))

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13 pages, 3270 KB

Open AccessEditor’s ChoiceArticle

Secondary Production and Biomass Dynamics of Mediterranean Brown Trout (Salmo trutta Complex) in Pyrenean Headwater Streams

by Enric Aparicio, Rafel Rocaspana and Carles Alcaraz

Fishes 2025, 10(10), 476; https://doi.org/10.3390/fishes10100476 - 23 Sep 2025

Cited by 1 | Viewed by 597

Abstract

Fish secondary production integrates multiple demographic parameters, including population density, growth, mortality, and recruitment, and thereby provides a comprehensive measure of ecological performance. It is also a valuable tool for assessing the ecological integrity of stream ecosystems and the responses of fish populations [...] Read more.

Fish secondary production integrates multiple demographic parameters, including population density, growth, mortality, and recruitment, and thereby provides a comprehensive measure of ecological performance. It is also a valuable tool for assessing the ecological integrity of stream ecosystems and the responses of fish populations to habitat alteration, climatic variability, and anthropogenic pressures. Despite its relevance, empirical estimates of fish production remain limited due to methodological constraints. In this study, we quantified secondary production and production-to-biomass (P/B) ratios for Mediterranean brown trout (Salmo trutta complex) across six headwater stream reaches in the northeastern Iberian Peninsula, characterized by contrasting hydrological regimes, channel morphology, and water chemistry. Field sampling was conducted over two consecutive annual cycles (2008/2009 and 2009/2010) at all sites, with extended monitoring at two reaches until 2017 to assess long-term variability. Annual trout production, over the two consecutive annual cycles, ranged from 30.9 to 167.8 kg ha⁻¹ year⁻¹ (mean = 82.2 kg ha⁻¹ year⁻¹), and mean P/B ratios ranged from 0.61 to 1.13 (mean = 0.80). These values fall within the intermediate range reported for brown trout globally and reflect the constrained energy dynamics of Mediterranean streams. Higher production was generally associated with strong age-1 recruitment, elevated standing biomass, and greater water alkalinity. Long-term analyses revealed that interannual variation in trout production was significantly correlated with discharge variability, with higher production occurring under more stable flow conditions. However, in addition to flow variability other factors, such as habitat complexity, may modulate local productivity. Consequently, interannual fluctuations at the long-term sites revealed substantial demographic variability influenced by site-specific environmental conditions. These findings offer reference baselines for Mediterranean trout populations and contribute to the ecological basis for their conservation and management. Full article

(This article belongs to the Special Issue The Roles of Fishery Biology and Fish Population Dynamics in Fisheries Management)

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25 pages, 11592 KB

Open AccessEditor’s ChoiceArticle

Pascua marecoralliensis, a New Species of Goby (Gobiiformes, Gobiidae) from the Central Coral Sea with Validation of the Genus Pascua

by Christopher H. R. Goatley, Andrea I. Varela, Javier Sellanes and Luke Tornabene

Fishes 2025, 10(9), 449; https://doi.org/10.3390/fishes10090449 - 4 Sep 2025

Viewed by 2311

Abstract

In this paper, we use molecular phylogenetics, micro-CT scanning, and morphological analyses to describe a new species of goby, Pascua marecoralliensis, and demonstrate that the genus Pascua is distinct from Hetereleotris, as supported by five diagnostic characters, including modified basicaudal scales [...] Read more.

In this paper, we use molecular phylogenetics, micro-CT scanning, and morphological analyses to describe a new species of goby, Pascua marecoralliensis, and demonstrate that the genus Pascua is distinct from Hetereleotris, as supported by five diagnostic characters, including modified basicaudal scales and reduced sensory papillae patterns. Phylogenetic analysis places Pascua as sister to the Gobiodon group, while Hetereleotris forms a separate clade. The new species, P. marecoralliensis, differs from congeners in fin ray counts, cephalic pore patterns, and head morphology and exhibits unique live colouration. Additionally, we reclassify Hetereleotris readerae and H. sticta as Pascua readerae and P. sticta based on shared genus-specific traits. The distribution of Pascua spans the southern Pacific, suggesting a relict lineage or undiscovered diversity in the genus. This work underscores the importance of integrative taxonomic approaches for resolving cryptic diversity in gobioid fishes and highlights the need for further sampling in understudied regions. Full article

(This article belongs to the Section Taxonomy, Evolution, and Biogeography)

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14 pages, 813 KB

Open AccessEditor’s ChoiceArticle

The Influence of Different Feeding Time Management on the Growth and Stress Response of the African Catfish Clarias gariepinuns (Burchel, 1822) Under Farming Conditions

by Marc-C. Hildebrand, David Runge, Björn Bassmann and Harry W. Palm

Fishes 2025, 10(8), 414; https://doi.org/10.3390/fishes10080414 - 18 Aug 2025

Cited by 1 | Viewed by 1789

Abstract

In this study, the growth and welfare of the African catfish (Clarias gariepinus, Burchell 1822) were investigated under industrial farming conditions. For this purpose, the growing success (cm, g) and typical stress related parameters (glucose-, lactate-, cortisol-concentrations, growth hormone, HSI-liver index) [...] Read more.

In this study, the growth and welfare of the African catfish (Clarias gariepinus, Burchell 1822) were investigated under industrial farming conditions. For this purpose, the growing success (cm, g) and typical stress related parameters (glucose-, lactate-, cortisol-concentrations, growth hormone, HSI-liver index) were investigated on the African catfish (102–841 g) in relation to an external stressor (working light and noise) and different feeding regimes (day, night, and day and night feeding) over 83 days. As no significant effects were found among the experimental feeding treatments in relation to the growth performance and investigated stress parameters, the time of feeding seems to have less impact to the production success and stress reactions as suggested before. Regarding our results, the effect of feeding conditioning could have played a strong factor likewise the ageing process of the reared fish species which is known to be rather photophobic. Therefore, the factor of conditioning and its influence to the time shift in feeding regimes and the impact of noise and light stressors during feeding should be investigated separately in future experiments to obtain further results in this context and clarify the validity of the best feeding conditions for African catfish. Full article

(This article belongs to the Special Issue Physiological Response Mechanisms of Aquatic Animals to Stress)

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23 pages, 676 KB

Open AccessFeature PaperEditor’s ChoiceReview

Stunted Versus Normally Growing Fish: Adapted to Different Niches

by Bror Jonsson

Fishes 2025, 10(8), 376; https://doi.org/10.3390/fishes10080376 - 4 Aug 2025

Cited by 1 | Viewed by 2180

Abstract

This literature-based review draws on studies of thirty-four fish species; most are from northern temperate regions. Fish have flexible and indeterminate growth, and often they do not reach their growth and size potential. They may become stunted with impaired growth and early maturity, [...] Read more.

This literature-based review draws on studies of thirty-four fish species; most are from northern temperate regions. Fish have flexible and indeterminate growth, and often they do not reach their growth and size potential. They may become stunted with impaired growth and early maturity, chiefly as a phenotypically plastic reaction. The main causes of stunted growth are negatively density-dependent food availability and keen intraspecific competition leading to environmental stress. Typically, their growth levels off early in life as energy consumptions approach energy costs of maintenance. Females typically attain maturity soon after the energy surplus from feeding starts to decrease. Males are often more variable in size at maturity owing to alternative mating strategies, and their size at maturity depends on both species-specific mating behaviours and environmental opportunities. In polyphenic/polymorphic populations, one phenotype may be stunted and the other phenotype non-stunted; stunted individuals do not perform the required ontogenetic niche shift needed to grow larger. The adult morphology of stunted fish is typically like the morphology of juveniles. Their secondary sexual characters are less pronounced, and they phenotypically retain adaptation to their early feeding niche, which is different from that of large-growing individuals. There are open questions regarding to what extent genetics and epigenetics regulate the life histories of stunted phenotypes. Full article

(This article belongs to the Special Issue Habitat as a Template for Life Histories of Fish)

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21 pages, 1379 KB

Open AccessEditor’s ChoiceArticle

Stream Temperature, Density Dependence, Catchment Size, and Physical Habitat: Understanding Salmonid Size Variation Across Small Streams

by Kyle D. Martens and Warren D. Devine

Fishes 2025, 10(8), 368; https://doi.org/10.3390/fishes10080368 - 1 Aug 2025

Viewed by 1179

Abstract

The average body size (fork length) of juvenile salmonids in small streams varies across landscapes and can be influenced by stream temperature, density dependence, catchment size, and physical habitat. In this study, we compared sets of 16 mixed-effects linear models representing these four [...] Read more.

The average body size (fork length) of juvenile salmonids in small streams varies across landscapes and can be influenced by stream temperature, density dependence, catchment size, and physical habitat. In this study, we compared sets of 16 mixed-effects linear models representing these four potentially influencing indicators for three species/age classes to assess the relative importance of their influences on body size. The global model containing all indicators was the most parsimonious model for juvenile coho salmon (Oncorhynchus kisutch; R²m = 0.4581, R²c = 0.5859), age-0 trout (R²m = 0.4117, R²c = 0.5968), and age-1 or older coastal cutthroat trout (O. clarkii; R²m = 0.2407, R²c = 0.5188). Contrary to expectations, salmonid density, catchment size, and physical habitat metrics contributed more to the top models for both coho salmon and age-1 or older cutthroat trout than stream temperature metrics. However, a stream temperature metric, accumulated degree days, had the only significant relationship (positive) of the indicators with body size in age-0 trout (95% CI 1.58 to 23.04). Our analysis identifies complex relationships between salmonid body size and environmental influences, such as the importance of physical habitat such as pool size and boulders. However, management or restoration actions aimed at improving or preventing anticipated declines in physical habitat such as adding instream wood or actions that may lead to increasing pool area have potential to ensure a natural range of salmonid body sizes across watersheds. Full article

(This article belongs to the Special Issue Habitat as a Template for Life Histories of Fish)

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27 pages, 1569 KB

Open AccessEditor’s ChoiceReview

Bisphenols: Endocrine Disruptors and Their Impact on Fish: A Review

by Nikola Peskova and Jana Blahova

Fishes 2025, 10(8), 365; https://doi.org/10.3390/fishes10080365 - 29 Jul 2025

Cited by 2 | Viewed by 4074

Abstract

Bisphenols (BPs), particularly bisphenol A (BPA) and its structural analogues, are synthetic compounds widely used in plastics and industrial materials. These substances are also recognised as endocrine-disrupting chemicals (EDCs) due to their ability to interfere with hormonal systems, which has significant implications for [...] Read more.

Bisphenols (BPs), particularly bisphenol A (BPA) and its structural analogues, are synthetic compounds widely used in plastics and industrial materials. These substances are also recognised as endocrine-disrupting chemicals (EDCs) due to their ability to interfere with hormonal systems, which has significant implications for aquatic organisms. This review summarises the occurrence, environmental distribution, and toxicity of BPs in fish, with a focus on estrogenic, androgenic, thyroid, and glucocorticoid disruptions. Studies consistently show that exposure to BPs leads to altered gene expression, developmental abnormalities, impaired reproduction, and disrupted hormonal signalling in various fish species. Although BPA alternatives like bisphenol S, bisphenol F, or bisphenol AF were introduced as safer options, emerging evidence suggests they may pose equal or greater risks. Regulatory measures are evolving, particularly within the European Union, but legislation remains limited for many bisphenol analogues. This review emphasises the need for comprehensive environmental monitoring, stricter regulatory frameworks, and the development of genuinely safer alternatives to minimise the ecological and health impacts of BPs in aquatic systems. Full article

(This article belongs to the Section Environment and Climate Change)

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16 pages, 993 KB

Open AccessEditor’s ChoiceReview

The Application of Digital Twin Technology in the Development of Intelligent Aquaculture: Status and Opportunities

by Jianlei Chen, Yong Xu, Hao Li, Xinguo Zhao, Yang Su, Chunhao Qi, Keming Qu and Zhengguo Cui

Fishes 2025, 10(8), 363; https://doi.org/10.3390/fishes10080363 - 25 Jul 2025

Cited by 9 | Viewed by 3911

Abstract

Aquaculture is vital for global food security but faces challenges like disease, water quality control, and resource optimization. Digital twin technology, a real-time virtual replica of physical aquaculture systems, emerges as a transformative solution. By integrating sensors and data analytics, it enables monitoring [...] Read more.

Aquaculture is vital for global food security but faces challenges like disease, water quality control, and resource optimization. Digital twin technology, a real-time virtual replica of physical aquaculture systems, emerges as a transformative solution. By integrating sensors and data analytics, it enables monitoring and optimization of water quality, feed efficiency, fish health, and operations. This review explores the current adoption status of digital twins in aquaculture, highlighting applications in real-time monitoring and system optimization. It addresses key implementation challenges, including data integration and scalability, and identifies emerging opportunities for advancing sustainable, intelligent aquaculture practices. Full article

(This article belongs to the Special Issue Application of Artificial Intelligence in Aquaculture)

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19 pages, 2552 KB

Open AccessEditor’s ChoiceArticle

The Biogeographic Patterns of Two Typical Mesopelagic Fishes in the Cosmonaut Sea Through a Combination of Environmental DNA and a Trawl Survey

by Yehui Wang, Chunlin Liu, Mi Duan, Peilong Ju, Wenchao Zhang, Shuyang Ma, Jianchao Li, Jianfeng He, Wei Shi and Yongjun Tian

Fishes 2025, 10(7), 354; https://doi.org/10.3390/fishes10070354 - 17 Jul 2025

Viewed by 1086

Abstract

Investigating biodiversity in remote and harsh environments, particularly in the Southern Ocean, remains costly and challenging through traditional sampling methods such as trawling. Environmental DNA (eDNA) sampling, which refers to sampling genetic material shed by organisms from environmental samples (e.g., water), provides a [...] Read more.

Investigating biodiversity in remote and harsh environments, particularly in the Southern Ocean, remains costly and challenging through traditional sampling methods such as trawling. Environmental DNA (eDNA) sampling, which refers to sampling genetic material shed by organisms from environmental samples (e.g., water), provides a more cost-effective and sustainable alternative to traditional sampling approaches. To study the biogeographic patterns of two typical mesopelagic fishes, Antarctic lanternfish (Electrona antarctica) and Antarctic deep-sea smelt (Bathylagus antarcticus), in the Cosmonaut Sea in the Indian Ocean sector of the Southern Ocean, we conducted both eDNA and trawling sampling at a total of 86 stations in the Cosmonaut Sea during two cruises in 2021–2022. Two sets of species-specific primers and probes were developed for a quantitative eDNA analysis of two fish species. Both the eDNA and trawl results indicated that the two fish species are widely distributed in the Cosmonaut Sea, with no significant difference in eDNA concentration, biomass, or abundance between stations. Spatially, E. antarctica tended to be distributed in shallow waters, while B. antarcticus tended to be distributed in deep waters. Vertically, E. antarctica was more abundant above 500 m, while B. antarcticus had a wider range of habitat depths. The distribution patterns of both species were affected by nutrients, with E. antarctica additionally affected by chlorophyll, indicating that their distribution is primarily influenced by food resources. Our study provides broader insight into the biogeographic patterns of the two mesopelagic fishes in the remote Cosmonaut Sea, demonstrates the potential of combining eDNA with traditional methods to study biodiversity and ecosystem dynamics in the Southern Ocean and even at high latitudes, and contributes to future ecosystem research and biodiversity conservation in the region. Full article

(This article belongs to the Section Biology and Ecology)

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24 pages, 1937 KB

Open AccessEditor’s ChoiceArticle

Asparagopsis taxiformis Feed Supplementation as a Tool to Improve the Resilience of Farmed Diplodus sargus to Marine Heatwave Events—A Metabolomics Approach

by Marta Dias, Isa Marmelo, Carla António, Ana M. Rodrigues, António Marques, Mário S. Diniz and Ana Luísa Maulvault

Fishes 2025, 10(7), 350; https://doi.org/10.3390/fishes10070350 - 15 Jul 2025

Viewed by 1657

Abstract

The need to maximize aquaculture production while addressing environmental and food security challenges posed by climate change has driven research towards the development of functional aquafeeds that enhance performance and immunity in farmed species. However, exposure to dietary and environmental stressors affects marine [...] Read more.

The need to maximize aquaculture production while addressing environmental and food security challenges posed by climate change has driven research towards the development of functional aquafeeds that enhance performance and immunity in farmed species. However, exposure to dietary and environmental stressors affects marine organisms, altering key metabolic pathways best understood through high-throughput “omics” tools. This study assessed the effects of Asparagopsis taxiformis supplementation on central metabolic pathways by analyzing changes in primary metabolite levels in the liver of farmed Diplodus sargus under optimal and suboptimal temperature conditions. Results showed that seaweed supplementation had a beneficial effect on the fish’s primary metabolome; however, inclusion levels and rearing conditions played a crucial role in determining outcomes. While 1.5% supplementation maintained a balanced primary metabolome under optimal temperature conditions, 3.0% supplementation most effectively mitigated the adverse effects of acute thermal stress during a marine heatwave. These findings highlight the nutritive and functional potential of A. taxiformis supplementation in aquafeeds for marine omnivorous fish species and emphasize the importance of evaluating functional aquafeeds under suboptimal rearing conditions. Overall, our results demonstrate the value of metabolomics in elucidating the molecular basis underlying biological pathways in farmed marine fish and optimizing production through climate-smart dietary strategies. Full article

(This article belongs to the Special Issue Advances in Aquaculture Feed Additives)

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55 pages, 3773 KB

Open AccessEditor’s ChoiceReview

Molecular Mechanisms and Biomarker-Based Early-Warning Indicators of Heavy Metal Toxicity in Marine Fish

by Andra Oros, Valentina Coatu, Nicoleta Damir, Diana Danilov, Elena Ristea and Luminita Lazar

Fishes 2025, 10(7), 339; https://doi.org/10.3390/fishes10070339 - 10 Jul 2025

Cited by 5 | Viewed by 4781

Abstract

Heavy metals are among the most persistent and bioaccumulative pollutants in marine ecosystems, posing significant toxicological threats to fish via complex molecular and cellular disruptions. This review synthesizes current knowledge on the cascade of mechanistic responses in marine fish following HM exposure, which [...] Read more.

Heavy metals are among the most persistent and bioaccumulative pollutants in marine ecosystems, posing significant toxicological threats to fish via complex molecular and cellular disruptions. This review synthesizes current knowledge on the cascade of mechanistic responses in marine fish following HM exposure, which includes oxidative stress, modulation of antioxidant responses, activation of detoxification systems, DNA damage, inflammation, apoptosis, neuroendocrine disruption, and ultimately, cellular energy imbalance. In addition to established pathways, the review highlights recent advances in mechanistic understanding and biomarker development, including cellular stress responses, epigenetic regulation, metal homeostasis mechanisms, and novel molecular indicators. These mechanisms support the development of an integrated biomarker framework that combines classical indicators (e.g., antioxidant enzymes, metallothionein) with next-generation endpoints (e.g., miRNA profiles, gene-level responses of metal transporters or stress chaperones, epigenetic alterations). The interpretation of biomarker responses requires consideration of the exposure context, environmental variables, and physiological status to ensure accurate assessment of sublethal toxicity in field settings. By bridging mechanistic understanding with biomonitoring relevance, this review provides a comprehensive foundation for advancing molecular tools in pollution monitoring and risk assessment. Special emphasis is placed on biomarkers specific to heavy metal exposure, enhancing their diagnostic value relative to general stress indicators. Full article

(This article belongs to the Section Environment and Climate Change)

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14 pages, 665 KB

Open AccessEditor’s ChoiceArticle

Evaluation of Three Atlantic Salmon Strains for Resistance to Copepodid Sea Lice Attachment

by Michael R. Pietrak, Thomas A. Delomas, Demitri Lifgren and Mark P. Polinski

Fishes 2025, 10(7), 334; https://doi.org/10.3390/fishes10070334 - 8 Jul 2025

Viewed by 1347

Abstract

Sea lice have been a persistent pest of the salmon farming industry for more than 50 years. In this study, we aimed to identify if different strains of Atlantic salmon with discrete long-term lice exposure histories had variable resistance to copepodid attachment and/or [...] Read more.

Sea lice have been a persistent pest of the salmon farming industry for more than 50 years. In this study, we aimed to identify if different strains of Atlantic salmon with discrete long-term lice exposure histories had variable resistance to copepodid attachment and/or different attachment-specific transcriptome patterns. We additionally sought to characterize lice distributions on fins, head, and skin and identify if attachment location influenced transcriptomic profiles of lice. Lice counts were correlated with body size and highest on St. John River (SJR; open ocean-run) relative to Grand Lakes Stream (GLS; 200-year restricted ocean-run) or Sebago Lake (CAS; ~11,000 years landlocked) Atlantic salmon. However, lice density was similar between strains. Skin and fins had expectedly different transcriptomic profiles; however, notable differences were not observed between salmon strains. Variance in lice transcriptomes was minimally affected by attachment location even though lice strongly preferred fins relative to head or body. Attached lice did have different transcriptomic profiles on GLS relative to CAS or SJR. This study cumulatively identified a minimal host evolutionary component for sea lice attachment resistance, although lice behavior post-attachment appeared somewhat affected by strain. Non-uniform settlement distributions and tank-specific variability in lice attachment were observed across populations. Full article

(This article belongs to the Section Fish Pathology and Parasitology)

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15 pages, 1974 KB

Open AccessEditor’s ChoiceArticle

Comparing Year-Class Strength Indices from Longitudinal Analysis of Catch-at-Age Data with Those from Catch-Curve Regression: Application to Lake Huron Lake Trout

by Ji X. He and Charles P. Madenjian

Fishes 2025, 10(7), 332; https://doi.org/10.3390/fishes10070332 - 7 Jul 2025

Cited by 1 | Viewed by 1168

Abstract

Fish year-class strength (YCS) has been estimated via longitudinal analysis of catch-at-age data and via catch-curve regression, but no study has compared the two approaches. The objective of this study was to compare YCS estimates between the two approaches with application to the [...] Read more.

Fish year-class strength (YCS) has been estimated via longitudinal analysis of catch-at-age data and via catch-curve regression, but no study has compared the two approaches. The objective of this study was to compare YCS estimates between the two approaches with application to the lake trout (Salvelinus namaycush) population in the main basin of Lake Huron, one of the Laurentian Great Lakes of North America. YCSs were reconstructed for both hatchery-stocked and wild lake trout. Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used to compare 14 linear mixed-effects models for longitudinal analysis of catch-at-age data, and three linear mixed-effects models for catch-curve regression. From the best models based on AIC or BIC comparisons, YCS estimates with year-class as a fixed effect were consistent with those estimated with year-class as a random effect. Estimated YCS patterns and trends were the same or similar between the longitudinal analysis and the catch-curve regression, indicating that both approaches provide robust estimates of YCS. Potential bias in using the approach of catch-curve regression could be caused by abrupt changes in adult mortality. It is also critical to recognize multiple recruitment origins for using the approach of longitudinal analysis of catch-at-age data. Full article

(This article belongs to the Section Biology and Ecology)

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15 pages, 2654 KB

Open AccessEditor’s ChoiceArticle

Presence and Potential Effect of Microplastics Associated with Anthropic Activity in Two Benthic Fishes Serranus scriba and Lithognathus mormyrus

by Amanda Cohen-Sánchez, Juan Alejandro Sanz, Montserrat Compa, Maria Magdalena Quetglas-Llabrés, Maria del Mar Ribas-Taberner, Lorenzo Gil, Silvia Tejada, Samuel Pinya and Antoni Sureda

Fishes 2025, 10(7), 323; https://doi.org/10.3390/fishes10070323 - 3 Jul 2025

Viewed by 1132

Abstract

Plastic pollution poses a massive problem to the environment, particularly seas and oceans. Microplastics (MPs) ingestion by marine species can generate many adverse effects, including causing oxidative stress. This study evaluated the effects of anthropic activity-related MP presence in two coastal fish species— [...] Read more.

Plastic pollution poses a massive problem to the environment, particularly seas and oceans. Microplastics (MPs) ingestion by marine species can generate many adverse effects, including causing oxidative stress. This study evaluated the effects of anthropic activity-related MP presence in two coastal fish species—Serranus scriba (more related to rocky bottoms) and Lithognathus mormyrus (more related to sandy bottoms)—in two areas of Mallorca Island (Western Mediterranean) with varying anthropic pressures with similar mixed rocky/sandy bottoms. A total of eight fish samples per species and per area (total n = 32), as well as three water samples (500 mL each) and three sediment samples per area, were collected and analyzed. The results showed that despite plastic presence in both areas, the area with higher tourism affluence was also the most polluted. Fourier transform infrared spectroscopy analysis confirmed that the majority of recovered polymers were polyethylene and polypropylene. The pattern of MPs presence was reflected in the biomarker analysis, which showed higher values of antioxidants, namely catalase (CAT) and superoxide dismutase (SOD); detoxification, namely glutathione s-transferase (GST); and inflammation, namely myeloperoxidase (MPO)—enzymes in the gastrointestinal tract of fish from the more polluted area. However, no statistical differences were found for malondialdehyde (MDA) as a marker of lipid peroxidation. As for differences between species, S. scriba presented a higher presence of MPs and measured biomarkers than in L. Mormyrus, suggesting higher exposure. In conclusion, these results showed that increased anthropic activity is associated with a higher presence of MPs which, in turn, induces an adaptative response in exposed fish. Moreover, species living in the same area could be differentially affected by MPs, which is probably associated with different behavioural and feeding habits. Full article

(This article belongs to the Section Environment and Climate Change)

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20 pages, 723 KB

Open AccessEditor’s ChoiceArticle

Changes in Subcellular Responses in the Digestive Gland of the Freshwater Mussel Unio crassus from a Historically Contaminated Environment

by Zoran Kiralj, Zrinka Dragun, Jasna Lajtner, Krešimira Trgovčić, Tatjana Mijošek Pavin, Bruno Bušić and Dušica Ivanković

Fishes 2025, 10(7), 317; https://doi.org/10.3390/fishes10070317 - 2 Jul 2025

Cited by 3 | Viewed by 1000

Abstract

Utilizing a multi-biomarker approach, we assessed the potential adverse effects of pollutants on subcellular responses in the digestive gland of the freshwater mussel Unio crassus from a historically contaminated lowland section (KIZ) of the river Mrežnica compared to its less impacted upstream karstic [...] Read more.

Utilizing a multi-biomarker approach, we assessed the potential adverse effects of pollutants on subcellular responses in the digestive gland of the freshwater mussel Unio crassus from a historically contaminated lowland section (KIZ) of the river Mrežnica compared to its less impacted upstream karstic section (REF) and their seasonality (spring vs. autumn). This approach accounted for the diverse modes of action of pollutants by including biomarkers of metal exposure (metallothioneins, MT), general stress (total cytosolic proteins, TP), antioxidative capacity (catalase, CAT; glutathione, GSH; glutathione-S-transferase, GST), oxidative damage (malondialdehyde, MDA), and neurotoxicity (acetylcholinesterase, AChE). Only in spring, MT concentrations were 15% higher at the REF site (4.38 ± 1.06 µg mg proteins⁻¹) compared to the KIZ site (3.69 ± 0.63 µg mg proteins⁻¹), likely related to elevated Cd bioaccumulation due to the karstic substrate. Regardless of the season, mussels from KIZ showed consistently lower TP and GSH, with significantly higher CAT, GST, and MDA levels, indicating elevated stress, activation of antioxidant defenses, and oxidative damage from chronic exposure to pro-oxidant pollutants, including metal(loid)s and organic contaminants (e.g., ibuprofen, nicotine). Compared to the REF site, AChE activity at the KIZ site was higher in late spring and lower in early autumn, indicating seasonal variability in AChE activity at the contamination-impacted location driven by fluctuating exposure to neurotoxicants, such as drugs and insecticides. Overall, biomarker responses indicated that mild historical pollution, reinforced by current low-capacity sources, has an observable impact on mussel health, posing long-term risks to sediment-dwelling aquatic organisms. Full article

(This article belongs to the Section Environment and Climate Change)

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13 pages, 593 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Sardine-Based Diet Mitigates Growth Depression at Low Temperatures in Juvenile Meagre (Argyrosomus regius, Asso 1801)

by Lav Bavčević, Slavica Čolak, Renata Barić, Siniša Petrović and Tin Klanjscek

Fishes 2025, 10(7), 314; https://doi.org/10.3390/fishes10070314 - 2 Jul 2025

Viewed by 1087

Abstract

Low seawater temperatures are expected to depress fish growth in aquaculture. However, recent evidence suggests diet composition may offer mitigation for some species. This study evaluated the impact of different diets on juvenile meagre (Argyrosomus regius) in cage farming at low [...] Read more.

Low seawater temperatures are expected to depress fish growth in aquaculture. However, recent evidence suggests diet composition may offer mitigation for some species. This study evaluated the impact of different diets on juvenile meagre (Argyrosomus regius) in cage farming at low seawater temperatures (average 15.19 °C), conditions known to typically suppress meagre growth. Three replicated groups of fish (initial weight ≈ 107 g) were fed for six months either sardines (group A) or commercial pellets (groups B/C, with group C moisturized). The results demonstrate that the nutritional profile of sardines effectively mitigates cold-induced growth reduction in meagre. While pellet-fed meagre experienced expected growth depression, sardine-fed meagre exhibited a doubled temperature growth coefficient (TGC) and an 80% higher final average weight than the pellet groups (A: 346.13 g, B: 194.44 g, C: 188.93 g). Full article

(This article belongs to the Special Issue Advancing Fish Nutrition Research for Sustainable Aquaculture)

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19 pages, 3260 KB

Open AccessEditor’s ChoiceArticle

Individual Variation in Movement Behavior of Stream-Resident Mediterranean Brown Trout (Salmo trutta Complex)

by Enric Aparicio, Rafel Rocaspana, Antoni Palau-Ibars, Neus Oromí, Dolors Vinyoles and Carles Alcaraz

Fishes 2025, 10(7), 308; https://doi.org/10.3390/fishes10070308 - 30 Jun 2025

Cited by 3 | Viewed by 1374

Abstract

Understanding individual movement patterns in stream-resident salmonids is critical for conservation and river management, particularly in Mediterranean streams characterized by high environmental variability. We tagged 997 Mediterranean brown trout (Salmo trutta complex) and conducted an 11-month mark–recapture study using Passive Integrated Transponder [...] Read more.

Understanding individual movement patterns in stream-resident salmonids is critical for conservation and river management, particularly in Mediterranean streams characterized by high environmental variability. We tagged 997 Mediterranean brown trout (Salmo trutta complex) and conducted an 11-month mark–recapture study using Passive Integrated Transponder (PIT) technology to assess movement behavior in the Flamisell River (Ebro Basin, northeastern Iberian Peninsula). Movements followed a leptokurtic distribution, with 81.8% of the individuals classified as sedentary (median movement = 24.9 m) and 18.2% as mobile (median movement = 376.2 m). Generalized linear models revealed distinct drivers of fish movement for each group. In sedentary trout, movement was mainly influenced by mesohabitat type, season, sex, and body size, with males and larger individuals moving farther. In mobile trout, mesohabitat type, density, and body size were key predictors. Movement patterns were repeatable over time, indicating consistent behavioral tendencies. These results support a bimodal movement strategy and highlight the importance of individual variation. Conservation planning should account for both sedentary and mobile groups to preserve functional and genetic connectivity and improve resilience of Mediterranean streams. Full article

(This article belongs to the Special Issue The Roles of Fishery Biology and Fish Population Dynamics in Fisheries Management)

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16 pages, 1657 KB

Open AccessEditor’s ChoiceArticle

Effect of the Inclusion of Natural Pigments on the Performance and Gene Expression of Immune Response and Oxidative Stress of Oreochromis niloticus Cultured in a Biofloc System

by Andres Elias Castro-Castellon, Maria del Carmen Monroy-Dosta, Aida Hamdan-Partida, Martha Patricia Hernandez-Vergara, Jorge Castro-Mejía, German Castro-Mejia, Arnulfo Misael Martinez-Meingüer and José Antonio Mata-Sotres

Fishes 2025, 10(6), 282; https://doi.org/10.3390/fishes10060282 - 8 Jun 2025

Viewed by 1333

Abstract

Tilapia (Oreochromis niloticus) is one of the most important species in aquaculture, so the optimization of its culture by using sustainable strategies is fundamental. The aim of this study was to evaluate the effects of incorporating natural pigments (carrot and beetroot [...] Read more.

Tilapia (Oreochromis niloticus) is one of the most important species in aquaculture, so the optimization of its culture by using sustainable strategies is fundamental. The aim of this study was to evaluate the effects of incorporating natural pigments (carrot and beetroot meal) as carbon sources in a biofloc system on the growth, immune response, and oxidative stress of O. niloticus. The experiment comprised four treatments: clear water as control (CT), biofloc with molasses (TBM), biofloc with carrot meal (TBC), and biofloc with beetroot meal (TBB). Results showed that biofloc helped to maintain optimal water quality and high survival rates, but specifically, TBC treatment achieved the highest growth rates and feed conversion ratio, along with elevated leukocyte counts, indicating improved health and immunity. Gene expression analysis revealed enhanced antioxidant activity (sod, gpx) and modulated immune responses (tnf-α, il-1β), particularly under thermal stress. Carrot meal emerged as an effective carbon source in biofloc systems, promoting growth, immune resilience, and oxidative stress resistance in tilapia, while beetroot meal improved pigmentation. These findings highlight the potential of natural pigments to enhance aquaculture sustainability and productivity. Full article

(This article belongs to the Special Issue Fish Hematology)

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14 pages, 4905 KB

Open AccessEditor’s ChoiceArticle

Effects of Micro- and Macroalgae-Supplemented Diets on Growth and Muscle Fibrillar Constitution of Gilthead Seabream, Sparus aurata L., in the Final On-Growing Phase

by María Dolores Ayala, Elena Chaves-Pozo, María Isabel Sáez, Francisco Javier Alarcón, Tomás Francisco Martínez and Marta Arizcun

Fishes 2025, 10(6), 262; https://doi.org/10.3390/fishes10060262 - 2 Jun 2025

Viewed by 1224

Abstract

The influence of algae in a final fattening diet for gilthead seabream, Sparus aurata, was studied in an 87 d feeding trial. Five groups were analysed (three tanks per group). In the first 38 days, one lot was fed with standard algae-free [...] Read more.

The influence of algae in a final fattening diet for gilthead seabream, Sparus aurata, was studied in an 87 d feeding trial. Five groups were analysed (three tanks per group). In the first 38 days, one lot was fed with standard algae-free feed (C1) and four batches were fed with an algae-free diet low in fishmeal (FM) and fish oil (FO) and rich in terrestrial vegetables (C2). Subsequently, the C2 diet was changed in three out of the four groups, two of them being fed a diet with a microalgae blend (10%) plus 2% macroalgae (Alaria esculenta), either in raw (C2-R) or hydrolysed (C2-H) form, and a third batch with a diet lacking FM and FO but supplemented with 10% microalgae and 7% algae oil (C2-O) for 49 days. Body length and weight, muscle parameters, and conversion index were analysed after 38 and 87 days. At day 38, no significant differences were observed in any parameter between C1 and C2, but at the end of the trial (day 87), C2 displayed the lowest weight gain and the worst conversion rate, whereas C2-R showed higher body weight, fibrillar hypertrophy, and better conversion rates than the other groups, and C2-H displayed higher hyperplasia values than the other groups. Full article

(This article belongs to the Special Issue Development of Low-Crop, Low-Fishmeal or Low-Fish Oil Feeds for Aquaculture)

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17 pages, 1604 KB

Open AccessEditor’s ChoiceArticle

Stable Isotope Analysis of Two Filter-Feeding Sharks in the Northwestern Pacific Ocean

by Chi-Ju Yu, Shoou-Jeng Joung, Hua-Hsun Hsu, Kwang-Ming Liu and Atsuko Yamaguchi

Fishes 2025, 10(6), 249; https://doi.org/10.3390/fishes10060249 - 26 May 2025

Cited by 2 | Viewed by 2432

Abstract

Understanding the feeding ecology and habitat use of vulnerable shark species is crucial for effective conservation. This study focuses on two large filter-feeding sharks, the megamouth shark (Megachasma pelagios) and whale shark (Rhincodon typus), in Northwestern Pacific waters. Stable [...] Read more.

Understanding the feeding ecology and habitat use of vulnerable shark species is crucial for effective conservation. This study focuses on two large filter-feeding sharks, the megamouth shark (Megachasma pelagios) and whale shark (Rhincodon typus), in Northwestern Pacific waters. Stable isotope analysis (δ¹³C and δ¹⁵N) was conducted on white muscle samples (n = 91) of M. pelagios and fin clips (n = 90) of R. typus, collected via large-mesh drift nets and set nets in Taiwanese waters. In this study, we investigated feeding strategies, ontogenetic dietary shifts, habitat use, and isotopic niche variation in both species. For R. typus, the observed positive correlation between δ¹³C and δ¹⁵N supports the previously proposed active suction filter feeding, as well as implying both a diet with an increasing proportion of higher trophic level prey and an ontogenetic shift. In contrast, M. pelagios displayed a negative correlation, consistent with a previous study associating such patterns with primary or secondary consumers, further aligning with its reported planktonic prey dominance. Both species had increasing δ¹³C with growth, signifying a shift to nutrient-rich habitats. Only R. typus exhibited ontogenetic diet changes (δ¹⁵N). SIBER (Stable Isotope Bayesian Ellipses in R) analysis revealed distinct feeding strategies and habitat use between the two species, potential sexual segregation, and wider isotopic niche widths for males in both species. The findings underscore the importance of considering species-specific behaviors and sex-based differences in conservation strategies. Full article

(This article belongs to the Section Biology and Ecology)

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23 pages, 11176 KB

Open AccessEditor’s ChoiceArticle

Multi-Omics Investigation of Fatty Acid Content Variations in Common Carp (Cyprinus carpio) Muscle: Integrating Genome, Transcriptome, and Lipid Profiling Data

by Kaikuo Wang, Qi Wang, Yingjie Chen, Yiming Cao, Ran Zhao, Shuangting Yu, Xiaoqing Sun, Yan Zhang and Jiongtang Li

Fishes 2025, 10(5), 234; https://doi.org/10.3390/fishes10050234 - 16 May 2025

Cited by 1 | Viewed by 1531

Abstract

Fatty acids (FAs), especially the polyunsaturated fatty acids (PUFAs), play pivotal roles in growth and development. Fish possess a remarkable ability to synthesize PUFAs, rendering them a crucial and significant source of these essential FAs for human consumption. Despite extensive research on the [...] Read more.

Fatty acids (FAs), especially the polyunsaturated fatty acids (PUFAs), play pivotal roles in growth and development. Fish possess a remarkable ability to synthesize PUFAs, rendering them a crucial and significant source of these essential FAs for human consumption. Despite extensive research on the metabolic processes of FAs, the primary processes underlying FA content variation and corresponding regulatory mechanisms remain largely unexplored. We quantified the muscular FA profiles of 304 common carp samples. High variation in muscle FA content among samples was observed, with the coefficients of variation ranging from 0.36 to 0.92. With genome-wide association studies (GWAS), we identified 1410 SNPs significantly associated with the FA content. The genetic variation at genes participating in oxidation, ubiquitination, and transcriptional factors was associated with the content of multiple FAs, while few variants were observed in the FA-synthesis genes. For the total PUFA (TPUFA) content, transcriptome analysis of groups with the highest and lowest TPUFA content identified 715 differentially expressed genes (DEGs), including genes involved in oxidation and ubiquitination. Using multiple genomic selection programs with the associated SNPs for FA content, we obtained high and positive correlations ranging from 0.65 to 0.92 between the real FA contents and estimated breeding values. These findings manifested the major-effect processes governing the differences in muscular FA content and their regulatory mechanisms. The optimal genomic selection programs provide novel and feasible perspectives to enhance FA content in common carp. Full article

(This article belongs to the Special Issue Molecular Design Breeding in Aquaculture)

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13 pages, 704 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Dietary Lauric Acid Supplementation Positively Affects Growth Performance, Oxidative and Immune Status of European Seabass Juveniles

by Filipa Fontinha, Nicole Martins, Rui Magalhães, Helena Peres and Aires Oliva-Teles

Fishes 2025, 10(5), 190; https://doi.org/10.3390/fishes10050190 - 22 Apr 2025

Cited by 4 | Viewed by 2742

Abstract

Lauric acid (LA), a medium-chain fatty acid (C12), can promote growth performance and decrease oxidative damage and lipid deposition in animals. This study aimed to evaluate the effect of dietary supplementation of lauric acid as a functional ingredient on European seabass juveniles’ growth [...] Read more.

Lauric acid (LA), a medium-chain fatty acid (C12), can promote growth performance and decrease oxidative damage and lipid deposition in animals. This study aimed to evaluate the effect of dietary supplementation of lauric acid as a functional ingredient on European seabass juveniles’ growth performance and intestine antioxidant and immunological status. For this purpose, four practical diets were formulated to be isoproteic and isolipidic, including 0, 0.5, 1, and 2% of LA, and fed to triplicate groups of European seabass juveniles (~12.7 g) for 61 days. Dietary LA supplementation did not affect growth performance, feed utilization, or whole-body composition, but feed intake increased at a concentration-dependent level. However, the plasmatic triglyceride content was increased at the higher level of LA supplementation. In the intestine, catalase and glutathione reductase activities and lipid peroxidation levels were lower in fish fed the 1% LA diet than in the control group. The hepatic LPO level was higher in fish fed 0.5% LA than in the control group. Fish fed the 1% LA diet presented lower intestinal expressions of caspase 3, tumor necrosis factor-alpha, interleukins 10, 6, and 1-β, and a lower plasma white blood cell number. Overall, up to 2% dietary supplementation of lauric acid as a functional ingredient showed a trend to improve European sea bass juveniles’ growth performance without affecting feed utilization. Moreover, 1% dietary inclusion of LA reduced intestinal lipid peroxidation and downregulated pro-inflammatory and anti-inflammatory genes, thus enhancing the intestine’s homeostatic status. Full article

(This article belongs to the Section Nutrition and Feeding)

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13 pages, 667 KB

Open AccessEditor’s ChoiceArticle

A Comparison of White Muscle Quality in Grass Carp Ctenopharyngodon idellus Fed with Commercial Feeds and Barley Malt

by Chongjiang Hu, Zheng Huang, Hongkang Liu, Dingrui Mo, Peng Fu, Haiyan Guo, Wei Jiang, Yong Xie and Yongjun Chen

Fishes 2025, 10(4), 185; https://doi.org/10.3390/fishes10040185 - 18 Apr 2025

Cited by 1 | Viewed by 1618

Abstract

This study was the first report regarding the application of barley malt (BM) for diets of aquaculture species. Triplicate groups of grass carp Ctenopharyngodon idellus with an initial size of about 1.2 kg were selected and fed with either BM or commercial feed [...] Read more.

This study was the first report regarding the application of barley malt (BM) for diets of aquaculture species. Triplicate groups of grass carp Ctenopharyngodon idellus with an initial size of about 1.2 kg were selected and fed with either BM or commercial feed (CF) to apparent satiation for 8 weeks in outdoor ponds connected with a flow-through aquaculture system. The results showed that the final body weight (1651 g) was lower in the BM fish than in the CF fish (1791 g). The edible part was lower in the BM fish than in the CF fish as indicated by the viscerosomatic index. Except for ash levels, which were lower in the fillet of the BM fish than for that of the CF fish, moisture, protein, and lipid levels were not impacted by the application of BM. Water-holding capacity indicators (drop loss, frozen exudation rate, and cooking loss) of grass carp muscle were not relevant to dietary modifications. Hematoxylin-eosin (HE) staining showed that the diameter of the myofibers was decreased while density was increased in response to the application of BM, which contributed to the improvement in textural properties (hardness, gumminess, and chewiness) in the muscle of the BM fish as compared to the CF fish. Glutamic acid level was highest, followed by aspartic acid, lysine, leucine, alanine, and arginine in grass carp muscle. Except three amino acids (proline, phenylalanine, and histidine), the amounts of the other 15 amino acids, essential amino acids, semi-essential amino acids, nonessential amino acids, and delicious amino acids were not impacted by different treatments, suggesting that the application of BM had a minor effect on the amino acid composition of grass carp muscle. Oleic acid (C18:1n-9), linoleic acid (C18:2n-6), and palmitic acid (C16:0) were the most abundant fatty acids in grass carp muscle. The amounts of poly-unsaturated fatty acid (PUFA) in the muscle decreased in response to the application of BM as the diet of grass carp, and n-6 PUFAs (C18:2n-6 and C20:2n-6) rather than n-3 PUFAs accounted for this change, which is beneficial for human health. In conclusion, the application of BM had minor impacts on the proximate composition and amino acid composition but improved textural properties and decreased n-6 PUFAs in the fillet of grass carp. Full article

(This article belongs to the Special Issue Growth, Metabolism, and Flesh Quality in Aquaculture Nutrition)

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18 pages, 2154 KB

Open AccessEditor’s ChoiceArticle

Reconstruction of Recreational Catch and Multi-Fisheries Stock Assessment of Hairtail (Trichiurus lepturus) in Korean Waters Under a Data-Limited Situation

by Sang Chul Yoon, Moo-Jin Kim, Heejoong Kang and Min-Je Choi

Fishes 2025, 10(4), 166; https://doi.org/10.3390/fishes10040166 - 8 Apr 2025

Cited by 3 | Viewed by 2086

Abstract

Accurate catch data are essential for effective fisheries management. This study reconstructs the historical recreational catch of hairtail (Trichiurus lepturus) in Korean waters by incorporating unreported catches to improve stock assessment accuracy. Using a Bayesian state-space surplus production model, we conducted [...] Read more.

Accurate catch data are essential for effective fisheries management. This study reconstructs the historical recreational catch of hairtail (Trichiurus lepturus) in Korean waters by incorporating unreported catches to improve stock assessment accuracy. Using a Bayesian state-space surplus production model, we conducted a multi-fishery stock assessment by integrating abundance indices from eight major fisheries. The multigear mean standardization (MGMS) method was applied to derive standardized CPUE indices for each fishery, providing a more comprehensive evaluation of stock trends. The results indicate that excluding recreational catches and multiple CPUE indices may lead to biased stock assessments of hairtail in Korean waters. Models using an integrated CPUE index (SMSC) yielded higher MSY and biomass estimates, suggesting a more optimistic stock condition, whereas fishery-specific CPUE models (MSC) provided more precautionary estimates. The Kobe plot analysis indicates recent stock recovery, but continued monitoring and adaptive management are required to ensure long-term sustainability. This study highlights the importance of integrating recreational catch data and multi-fishery approaches in stock assessments, particularly under data-limited conditions, to enhance resource management and policy decision-making. Full article

(This article belongs to the Special Issue The Roles of Fishery Biology and Fish Population Dynamics in Fisheries Management)

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20 pages, 2383 KB

Open AccessEditor’s ChoiceArticle

Age, Growth, and Mortality of the Common Pandora (Pagellus erythrinus, L. 1758) in the Central Aegean Sea: Insights into Population Dynamics

by Alexandros Theocharis, Sofia Vardali and Dimitris Klaoudatos

Fishes 2025, 10(4), 160; https://doi.org/10.3390/fishes10040160 - 4 Apr 2025

Cited by 4 | Viewed by 1845

Abstract

This study investigates the age, growth, and mortality of the common pandora (Pagellus erythrinus) in the Central Aegean Sea, providing critical insights into its population dynamics and sustainability. A total of 589 specimens were analyzed, identifying nine age cohorts with mean [...] Read more.

This study investigates the age, growth, and mortality of the common pandora (Pagellus erythrinus) in the Central Aegean Sea, providing critical insights into its population dynamics and sustainability. A total of 589 specimens were analyzed, identifying nine age cohorts with mean total lengths ranging from 13.18 cm to 32.94 cm. Growth parameters, estimated using the von Bertalanffy growth model, yielded an asymptotic length (L∞) of 39.53 cm and a growth coefficient (k) of 0.16 year⁻¹, indicating moderate growth rates. The population exhibited non-isomorphic growth (b = 2.49, R² = 98.4), suggesting slower weight gain relative to length. Mortality estimates indicated natural mortality (M) at 0.321 year⁻¹, total mortality (Z) at 0.52 year⁻¹, and fishing mortality (F) at 0.2 year⁻¹, resulting in an exploitation rate (E) of 0.38. The fishing mortality at maximum sustainable yield (FMSY) was estimated at 0.33, with an exploitation rate at MSY (EMSY) of 0.51, suggesting that the population is currently harvested sustainably but close to the threshold of overexploitation. These findings provide essential reference points for fisheries management and highlight the need for continuous monitoring to ensure the long-term sustainability of P. erythrinus in Greek waters. Full article

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17 pages, 2047 KB

Open AccessEditor’s ChoiceArticle

You Are What You Eat: California Sea Cucumbers Become “Fishier” After Integrated Multi-Trophic Aquaculture with Chinook Salmon

by Emaline M. Montgomery, Barb L. Cannon, Miki Nomura, Rodrigo B. Leme, Ian P. Forster and Christopher M. Pearce

Fishes 2025, 10(4), 154; https://doi.org/10.3390/fishes10040154 - 1 Apr 2025

Viewed by 1490

Abstract

Recent interest in integrated multi-trophic aquaculture (IMTA) as an ecologically-sustainable and climate-conscious aquaculture system has resulted in testing different species partnerships and configurations in anticipation of industrialization. Deposit feeders like the California sea cucumber (Apostichopus californicus) have been suggested as ideal [...] Read more.

Recent interest in integrated multi-trophic aquaculture (IMTA) as an ecologically-sustainable and climate-conscious aquaculture system has resulted in testing different species partnerships and configurations in anticipation of industrialization. Deposit feeders like the California sea cucumber (Apostichopus californicus) have been suggested as ideal partners for IMTA with finfish, due to their ability to consume fish waste as well as their passive nature. However, the nutritional impacts of feeding on fish waste in IMTA have not yet been established for this species. The present study tested the effect of 3 months of inclusion in IMTA with Chinook salmon (Oncorhynchus tshawytscha) on the fatty-acid and nitrogenous-metabolite profiles of California sea cucumbers. The fatty-acid profiles of IMTA sea cucumbers showed significant changes from wild reference individuals, while few differences were detected in amino acids and other nitrogenous metabolites. Sea cucumbers housed directly in cages with salmon showed distinct shifts in their fatty-acid profiles toward higher levels of MUFAs and lower levels of SFAs, while PUFA concentrations remained the same. Sea cucumbers included in IMTA with finfish may be even more healthful for humans due to the accumulation of certain unsaturated fatty acids in their tissues not seen in wild reference individuals. Full article

(This article belongs to the Special Issue Advances in Integrated Multi-Trophic Aquaculture)

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19 pages, 1068 KB

Open AccessEditor’s ChoiceArticle

Impact of Dietary Glutamate on Growth Performance and Flesh Quality of Largemouth Bass

by Bo Zhao, Ju Zhao, Haifeng Liu, Hailong Zhang, Hongying Shan, Jiali Zong, Quanquan Cao and Jun Jiang

Fishes 2025, 10(4), 151; https://doi.org/10.3390/fishes10040151 - 31 Mar 2025

Cited by 6 | Viewed by 2100

Abstract

The influence of dietary glutamate (Glu) was evaluated in a 56-day feeding trial on the growth performance and flesh quality of largemouth bass (Micropterus salmoides). A total of 1170 fish (average body weight 24.05 ± 0.22 g) were randomly allocated into [...] Read more.

The influence of dietary glutamate (Glu) was evaluated in a 56-day feeding trial on the growth performance and flesh quality of largemouth bass (Micropterus salmoides). A total of 1170 fish (average body weight 24.05 ± 0.22 g) were randomly allocated into six groups, with three replicates per group. They were fed diets containing Glu in levels of 11.40% (G1), 11.88% (G2), 12.53% (G3), 13.27% (G4), 14.33% (G5), and 15.62% (G6). We found that, over a 56-day feeding period, the final body weight (FBW) of largemouth bass was about 4–5 times the IBW. The FBW, percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER) initially increased and then decreased with elevating dietary Glu levels. Likewise, protein content, lipid content, apparent digestibility coefficient of dry matter (ADC_D), and apparent digestibility coefficient of protein (ADC_P) followed a similar pattern. Supplementation with Glu significantly improved the hepatosomatic index (HSI), viscerosomatic index (VSI), and relative gut length (RGL). Moreover, dietary Glu augmentation noticeably enhanced flesh composition such as muscle protein, ash, lipid, amino acid contents, and polyunsaturated fatty acids (PUFAs). Furthermore, dietary Glu supplementation enhanced muscle physicochemical quality (such as drip loss and pH), textural properties (adhesiveness and cohesiveness), and biochemical indices such as total protein (TP) and salt-soluble protein, while decreasing muscle cathepsin B (CtsB) and lactate dehydrogenase (LD) contents, thereby improving flesh quality. In conclusion, these findings suggest that Glu plays a crucial role in enhancing both growth performance and muscle quality in largemouth bass. The optimal dietary requirement for juvenile largemouth bass was estimated to be approximately 125.1 g/kg of diet based on SGR analysis. Full article

(This article belongs to the Section Nutrition and Feeding)

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15 pages, 649 KB

Open AccessEditor’s ChoiceArticle

Exploring Nationwide Oyster Aquaculture Data: An Index to Compare Regulatory, Production, and Economic Attributes of Oyster Aquaculture Among U.S. States and Regions

by Anthony R. Lima

Fishes 2025, 10(4), 138; https://doi.org/10.3390/fishes10040138 - 21 Mar 2025

Cited by 1 | Viewed by 3467

Abstract

Wild oyster reefs have been harvested for centuries and continue to face anthropogenic pressures, including climate change, pollution, and habitat reduction. Oyster aquaculture has grown to supplement depleted wild stocks and strengthen local economies, but development has not occurred at the same rate [...] Read more.

Wild oyster reefs have been harvested for centuries and continue to face anthropogenic pressures, including climate change, pollution, and habitat reduction. Oyster aquaculture has grown to supplement depleted wild stocks and strengthen local economies, but development has not occurred at the same rate across all regions. Across the United States, states have a variety of political and cultural influences that impact oyster aquaculture policy, constraining the ability to make direct comparisons among locations that could enhance aquaculture expansion in slower-to-develop states and regions. This research developed a four-part index to compare regulatory, production, and economic attributes of oyster aquaculture among 23 coastal states. The final index score—a summation of the four individual index components—provides a broad integrated view of oyster aquaculture across the U.S. The results indicate that coastal states in the U.S. Mid-Atlantic and New England regions have the greatest number of resource and policy attributes in place to support oyster aquaculture, whereas coastal states in the Gulf of Mexico and Western Pacific region have relatively less in the way of aquaculture-supporting structures. As the oyster aquaculture industry continues to grow in the U.S., results from this study can help organizations involved in oyster aquaculture to make informed decisions to expand permitting, leasing, and production systems, following the model from states who have been active in oyster aquaculture for decades. Mindful and cautious improvements can facilitate sustainable sources of seafood and stable income generation for coastal communities while reducing pressures on wild stocks. Full article

(This article belongs to the Special Issue Fisheries Monitoring and Management)

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26 pages, 4940 KB

Open AccessEditor’s ChoiceArticle

Integration of Gill and Intestinal Osmoregulatory Functions to Assess the Smoltification Window in Atlantic Salmon

by Jonás I. Silva-Marrero, Floriana Lai, Sigurd O. Handeland, Cindy Pedrosa, Virginie Gelebart, Pablo Balseiro, Juan Fuentes, Ivar Rønnestad and Ana S. Gomes

Fishes 2025, 10(3), 119; https://doi.org/10.3390/fishes10030119 - 8 Mar 2025

Cited by 3 | Viewed by 3325

Abstract

The transfer time of Atlantic salmon smolts from freshwater to seawater remains a challenge in aquaculture, with the “smolt window” referring to the optimal timeframe for seawater readiness. Our study monitored Atlantic salmon osmoregulatory adaptations during smoltification under continuous light (LL) and winter [...] Read more.

The transfer time of Atlantic salmon smolts from freshwater to seawater remains a challenge in aquaculture, with the “smolt window” referring to the optimal timeframe for seawater readiness. Our study monitored Atlantic salmon osmoregulatory adaptations during smoltification under continuous light (LL) and winter signal regime (6 weeks LD 12:12) followed by 6 or 8 weeks of constant light. Fish were subsequently reared in seawater for 8 weeks and subjected to a stress event of cyclic hypoxia at the conclusion of the trial. Significant differences in growth trajectories were observed between the LL and LD groups, with fish receiving the winter signal showing compensatory growth after seawater transfer. Gill Na⁺/K⁺-ATPase (NKA) activity, plasma ions, glucose, and cortisol levels confirmed the importance of the winter signal for seawater adaptation. Molecular markers, including nka isoforms, Na⁺-K⁺-2Cl⁻ cotransporter (nkcc), cystic fibrosis transmembrane conductance regulator (cftr), and Na⁺/HCO₃⁻ cotransporter (nbc), showed distinct temporal expression patterns, particularly in gills and midgut. Notably, the LD group with delayed seawater transfer exhibited enhanced growth and improved hypo-osmoregulatory capacity. These findings underscore the advantages of a winter signal in smoltification and suggest that delaying seawater transfer for up to 8 weeks could be beneficial. Full article

(This article belongs to the Special Issue Rhythms in Marine Fish and Invertebrates)

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22 pages, 1530 KB

Open AccessEditor’s ChoiceArticle

Investigation of Plasticity in Morphology, Organ Traits and Nutritional Composition in Chinese Soft-Shelled Turtle (Pelodiscus sinensis) Under Different Culturing Modes

by Ming Qi, Yang Wang, Liangliang Hu, Guangmei Chen, Tianlun Zheng, Xueyan Ding, Yijiang Bei, Jianjun Tang, Wenjun Ma and Xin Chen

Fishes 2025, 10(3), 89; https://doi.org/10.3390/fishes10030089 - 20 Feb 2025

Cited by 2 | Viewed by 2781

Abstract

The Chinese soft-shelled turtle (Pelodiscus sinensis) is an aquatic reptile prized for its nutritional and health benefits. Given its adaptability to various culturing modes including the greenhouse, pond and rice culturing modes, we conducted a comparative analysis of the morphology, organ [...] Read more.

The Chinese soft-shelled turtle (Pelodiscus sinensis) is an aquatic reptile prized for its nutritional and health benefits. Given its adaptability to various culturing modes including the greenhouse, pond and rice culturing modes, we conducted a comparative analysis of the morphology, organ trait and nutritional composition of turtles cultured in three culturing modes. This study investigated the plasticity of morphology and physiology, as well as the variations in nutritional composition across varying culturing modes. The results demonstrated that after approximately 120 days of cultivation, significant changes were observed in the morphology, physiology and nutritional composition of turtles from each culturing mode. In terms of morphology, rice turtles exhibited an arched shell shape, broad plastron, elongated limbs, narrow interocular distance and slender head and neck. Pond turtles displayed similar morphological characteristics to rice turtles, with the additional features of a flattened body shape and narrower plastron. Greenhouse turtles presented a flattened shell shape, narrow plastron, shortened limbs, wider interocular distance and stocky head and neck. Regarding the organ characteristics, the specific weights of liver, viscera, internal fat lumps and condition factors were significantly higher in greenhouse turtles compared to rice turtles and pond turtles (p < 0.05). Conversely, the specific weights of the back carapace, calipash and edible part were significantly lower than those in rice turtles and pond turtles (p < 0.05). Nutritional analysis revealed that crude protein, total amino acid, essential amino acid, flavor amino acid, pharmacodynamic amino acid, collagen and EPA+DHA contents were significantly higher in rice turtles and pond turtles than greenhouse turtles (p < 0.05). However, crude fat and unsaturated fatty acid contents were significantly higher in greenhouse turtles than in rice turtles and pond turtles (p < 0.05). In summary, Chinese soft-shelled turtles exhibited significant morphological and organ plasticity in response to different culturing modes. While the rice and pond culturing modes could enhance the nutritional quality of turtles to some extent, the impact of commercial feed on fatty acid profiles must be carefully considered. Full article

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23 pages, 3009 KB

Open AccessEditor’s ChoiceReview

Advancing Fisheries Research and Management with Computer Vision: A Survey of Recent Developments and Pending Challenges

by Jesse Eickholt, Jonathan Gregory and Kavya Vemuri

Fishes 2025, 10(2), 74; https://doi.org/10.3390/fishes10020074 - 12 Feb 2025

Cited by 2 | Viewed by 3027

Abstract

The field of computer vision has progressed rapidly over the past ten years, with noticeable improvements in techniques to detect, locate, and classify objects. Concurrent with these advances, improved accessibility through machine learning software libraries has sparked investigations of applications across multiple domains. [...] Read more.

The field of computer vision has progressed rapidly over the past ten years, with noticeable improvements in techniques to detect, locate, and classify objects. Concurrent with these advances, improved accessibility through machine learning software libraries has sparked investigations of applications across multiple domains. In the areas of fisheries research and management, efforts have centered on the localization of fish and classification by species, as such tools can estimate the health, size, and movement of fish populations. To aid in the interpretation of computer vision for fisheries research management tasks, a survey of the recent literature was conducted. In contrast to prior reviews, this survey focuses on employed evaluation metrics and datasets as well as the challenges associated with applying machine learning to a fisheries research and management context. Misalignment between applications and commonly used evaluation metrics and datasets mischaracterizes the efficacy of emerging computer vision techniques for fisheries research and management tasks. Aqueous, turbid, and variable lighted deployment settings further complicate the use of computer vision and generalizability of the reported results. Informed by these inherent challenges, culling surveillance data, exploratory data collection in remote settings, and selective passage and traps are presented as opportunities for future research. Full article

(This article belongs to the Section Fishery Economics, Policy, and Management)

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23 pages, 5624 KB

Open AccessEditor’s ChoiceArticle

Heat Shock Factors in the European Eel: Gene Characterization and Expression Response to Different Environmental Conditions and to Induced Sexual Maturation

by Leonor Ferrão, Luz Pérez, Juan F. Asturiano and Marina Morini

Fishes 2025, 10(2), 73; https://doi.org/10.3390/fishes10020073 - 12 Feb 2025

Cited by 1 | Viewed by 1552

Abstract

Heat shock factors (HSFs) are transcription factors that regulate responses to environmental changes and play roles in physiological mechanisms like spermatogenesis. This study analyzed the HSF gene family and their expression profiles in the European eel under different environmental conditions and during testis [...] Read more.

Heat shock factors (HSFs) are transcription factors that regulate responses to environmental changes and play roles in physiological mechanisms like spermatogenesis. This study analyzed the HSF gene family and their expression profiles in the European eel under different environmental conditions and during testis maturation. Six HSF genes were identified in the studied vertebrates, in which the eel presents two HSF1 paralogs (HSF1a and HSF1b), likely resulting from the teleost whole-genome duplication event, while only one paralog is present for the other HSF (HSF2, HSF4, and HSF5). All five HSF genes were highly expressed in the testis, but some were also detected in the brain, intestine, and gills. Our findings showed that HSF1 changed their expression in response to different temperature and salinity conditions, suggesting that these may support males in perceiving the temperature and salinity changes possibly found during reproductive migration. During hCGrec-induced spermatogenesis, HSF genes presented a decreasing expression profile throughout testis maturation (with significant differences in HSF1a and HSF4), except HSF5, which showed the highest levels after 4 weeks of hormonal treatment. Our study indicates that HSF genes are potentially implicated in the response to environmental changes perception and during gonadal maturation. Full article

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25 pages, 2423 KB

Open AccessEditor’s ChoiceArticle

Molecular Immune Responses of Ruditapes decussatus to Vibrio Infection at Different Temperatures: Expression of Key Genes and Resilience-Associated Single Nucleotide Polymorphisms

by Dimitrios K. Papadopoulos, Ioannis A. Giantsis, Athanasios Lattos, Konstantina Bitchava and Basile Michaelidis

Fishes 2025, 10(2), 72; https://doi.org/10.3390/fishes10020072 - 11 Feb 2025

Cited by 5 | Viewed by 1799

Abstract

The impact of pathogenic Vibrio on bivalves is expected to be aggravated by global warming, posing a growing threat to aquaculture. Clam production has been particularly vulnerable, with significant losses attributed to the lack of pathogen-resistant strains. In this study, the mantle cavity [...] Read more.

The impact of pathogenic Vibrio on bivalves is expected to be aggravated by global warming, posing a growing threat to aquaculture. Clam production has been particularly vulnerable, with significant losses attributed to the lack of pathogen-resistant strains. In this study, the mantle cavity of the grooved carpet shell clam Ruditapes decussatus (Linnaeus, 1758) was injected with Vibrio splendidus at 18 °C, 22 °C, and 24 °C and the transcription of the phagelysozyme, Cu-Zn superoxide dismutase (Cu-Zn sod), tumor necrosis factor receptor associated factor 6 (traf6), inhibitor of NF-κB (IκB), and Fas-associated protein with death domain (fadd) genes were assessed during a 20-day period. Additionally, the coding sequences of lysozyme, fadd, and IκB in Ruditapes decussatus were characterized for the first time, and SNPs were identified. Some SNPs showed significantly different distributions between infection-resistant and infection-susceptible individuals. Infected clams experienced increased mortality at elevated temperatures. Lysozyme mRNA was upregulated in infected groups across all temperatures. The sustained increase on day 20, coinciding with elevated traf6 mRNA, suggests a prolonged activation of the immune response. Cu-Zn sod transcription at 18 °C and 22 °C peaked on day 7 and returned to control levels by day 20, indicating an effective immune response, while at 24 °C, infected animals showed a continuously increased transcription. IκΒ and traf6 transcription, reflecting NF-κB pathway activity, varied with temperature and showed transient stimulation at higher temperatures. The pattern of fadd expression indicated a late induction of apoptosis, particularly at 18 °C and 24 °C. Overall, this study illustrates the involvement of five key genes in host–pathogen interactions and identifies potential markers for selection for Vibrio resistance in Ruditapes decussatus. However, given the weak correlation observed, further research is needed on the link between these polymorphisms and pathogen resilience. Full article

(This article belongs to the Special Issue Prevention and Control of Aquatic Animal Diseases)

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16 pages, 1240 KB

Open AccessEditor’s ChoiceArticle

Stock Structure of the Gulf Hake Urophycis cirrata (Teleostei: Phycidae) in South-Western Atlantic Using Otolith Shape and Elemental Analyses

by César Santificetur, Carmen Lúcia Del Bianco Rossi-Wongtschowski, André Ruperti, Agostinho Almeida, Edgar Pinto and Alberto Teodorico Correia

Fishes 2025, 10(2), 63; https://doi.org/10.3390/fishes10020063 - 4 Feb 2025

Cited by 2 | Viewed by 1425

Abstract

Urophycis cirrata is an important demersal fish species targeted by Brazilian industrial fisheries. With high exploitation rates, its stock(s) is(are) currently deemed fully exploited or overexploited. While basic ecological information, such as length at first maturity, exists, knowledge of its population structure is limited. [...] Read more.

Urophycis cirrata is an important demersal fish species targeted by Brazilian industrial fisheries. With high exploitation rates, its stock(s) is(are) currently deemed fully exploited or overexploited. While basic ecological information, such as length at first maturity, exists, knowledge of its population structure is limited. A sub-sample of 90 sagittal otoliths of U. cirrata juveniles (300–411 mm total length) collected during the Program for Assessment of the Sustainable Potential of Living Resources in the Exclusive Economic Zone (REVIZEE) in 2001/2002 was analyzed. Samples came from the outer continental shelf and upper slope of the southeast-south Brazilian coast, divided into three regions: northern (Cabo São Tomé to São Sebastião), central (São Sebastião to Cabo Santa Marta Grande), and southern (Cabo Santa Marta Grande to Chuí). Otolith shape (elliptic Fourier descriptors) and elemental (element:Ca) signatures were examined using univariate (ANOVA, Tukey) and multivariate (MANOVA, LDFA) statistical methods. An overall reclassification success rate of 86% was achieved using both signatures. However, individuals from the three regions were not fully separable, indicating a single, albeit not homogeneous, population unit for fisheries management. As fish stocks are dynamic, contemporary studies should be conducted to verify whether this population structure persists. Full article

(This article belongs to the Section Biology and Ecology)

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13 pages, 5211 KB

Open AccessEditor’s ChoiceArticle

Preferred and Optimal Swimming Speeds in Rainbow Trout (Oncorhynchus mykiss) at Three Temperatures

by Ólavur av Fløtum Mittún, Morten Bo Søndergaard Svendsen, Lars Emil Juel Andersen, Heiðrikur Bergsson and John Fleng Steffensen

Fishes 2025, 10(2), 64; https://doi.org/10.3390/fishes10020064 - 4 Feb 2025

Cited by 1 | Viewed by 2617

Abstract

Sustained exercise in aquaculture is known to improve the health and growth of finfish. Implementing exercise regimes has become an increasing focus in aquaculture practice. This study examined the relationship between the preferred swimming speed (U_pref) and the optimal swimming speed [...] Read more.

Sustained exercise in aquaculture is known to improve the health and growth of finfish. Implementing exercise regimes has become an increasing focus in aquaculture practice. This study examined the relationship between the preferred swimming speed (U_pref) and the optimal swimming speed (U_opt) in rainbow trout (Oncorhynchus mykiss) under non-migratory conditions typical of aquaculture environments. Using a circular raceway, rainbow trout were allowed to swim voluntarily to determine U_pref. U_opt was measured using a forced-swimming test in a swim tunnel respirometer. Experiments were conducted at three temperatures (10 °C, 15 °C, and 20 °C). The results revealed a significant difference between U_pref (1.18 ± 0.14, 1.17 ± 0.19, and 1.24 ± 0.15 BL s⁻¹, respectively) and U_opt (1.4 ± 0.19, 1.5 ± 0.15, and 1.6 ± 0.24 BL s⁻¹, respectively) across all temperatures. Aerobic scope was greatest at 15 °C (3.8), consistent with the species’ thermal range. Notably, swimming at U_pref required 18–22% less energy than U_opt, suggesting that U_pref is more suitable for aquaculture systems. This study introduces a minimally invasive and stress-free method for determining U_pref and provides insights that can optimize flow regimes in aquaculture tanks, improving both energy efficiency and fish welfare. Full article

(This article belongs to the Special Issue Technology for Fish and Fishery Monitoring)

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17 pages, 3447 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Using Nearshore Fish Communities to Evaluate Eutrophication Impact in Temperate Estuaries

by Mark D. Saunders, Nathanael Bergbusch, Kyle M. Knysh, Leah P. MacIntyre, Christina C. Pater, Michael R. S. Coffin, Monica Boudreau, Michael R. van den Heuvel and Simon C. Courtenay

Fishes 2025, 10(2), 55; https://doi.org/10.3390/fishes10020055 - 29 Jan 2025

Viewed by 1743

Abstract

Using fishes as indicators of estuarine degradation is informative in long-term monitoring programs. Beach seine hauls were used in four estuaries that differed in their trophic and tidal status. The study found that inner, middle, and outer estuarine nearshore fish communities differed significantly [...] Read more.

Using fishes as indicators of estuarine degradation is informative in long-term monitoring programs. Beach seine hauls were used in four estuaries that differed in their trophic and tidal status. The study found that inner, middle, and outer estuarine nearshore fish communities differed significantly at from all estuaries, for all sampling times. To reduce the effects of within-estuary variability, between-estuary differences were examined separately for inner, middle, and outer estuarine areas. These analyses revealed differences in north-south and trophic status in communities between estuaries. The north-south differences were characterized by more benthic fishes, such as mummichogs and fourspine stickleback in the microtidal northern estuaries and proportionally more pelagic fishes, such as Atlantic silversides and river herring in the mesotidal estuaries. In both multivariate and univariate analyses, mummichogs were also featured as being most abundant in the more eutrophic estuaries. The distance-based redundancy analysis showed that bare sediment coverage was the strongest correlate of the north-south differences, while the Ulva to Zostera plant gradient was more influential in predicting eutrophication impacts on communities in the inner and middle estuary. Full article

(This article belongs to the Section Environment and Climate Change)

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18 pages, 4001 KB

Open AccessEditor’s ChoiceArticle

Broadband Characteristics of Target Strength of Pacific Chub Mackerel

by Kohei Hasegawa, Naizheng Yan, Tohru Mukai, Yoshiaki Fukuda and Jun Yamamoto

Fishes 2025, 10(2), 51; https://doi.org/10.3390/fishes10020051 - 28 Jan 2025

Cited by 2 | Viewed by 1381

Abstract

Broadband backscattering measurements of Pacific mackerel (Scomber japonicus) can improve acoustic surveys of the species for the management of its fisheries throughout the Pacific Ocean. The determination of its target strength (TS), the logarithmic form of the backscattering cross-section, is the [...] Read more.

Broadband backscattering measurements of Pacific mackerel (Scomber japonicus) can improve acoustic surveys of the species for the management of its fisheries throughout the Pacific Ocean. The determination of its target strength (TS), the logarithmic form of the backscattering cross-section, is the aim of this work. It was measured for fourteen individual specimens, eight in a freshwater tank and six in a seawater tank, using calibrated broadband echosounders spanning the frequency band 24–84 kHz. The TS is expressed as a function of frequency and tilt angle, with fish length as a parameter. The individual broadband TS patterns with the tilt angle of fish showed size and frequency dependencies. The fish length-normalized TS of mackerel decreased with increasing fish length-to-acoustic wavelength ratio (l/λ) in the small l/λ range (approximately 2–6) but was flat in the larger l/λ range (>6). This variation in the normalized TS indicates that a pair of regression equations is necessary to span the range of commercially important mackerel relative to the acoustic wavelength. The relative l/λ characteristic of the normalized TS showed constant values with tilt-angle distributions over a large l/λ range and can be used as a characteristic of acoustic backscattering for discrimination among species. Full article

(This article belongs to the Section Fishery Facilities, Equipment, and Information Technology)

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14 pages, 2848 KB

Open AccessEditor’s ChoiceArticle

Establishing the Physiological Values of Minimally Invasive Biomarkers in Gilthead Sea Bream (Sparus aurata)

by Rafael Angelakopoulos, Andreas Tsipourlianos, Alexia E. Fytsili and Katerina A. Moutou

Fishes 2025, 10(2), 52; https://doi.org/10.3390/fishes10020052 - 28 Jan 2025

Viewed by 1419

Abstract

Peripheral blood has been always used as the mirror of physiological status in a minimally invasive manner. In homeothermic vertebrates, different blood parameters have been correlated to a variety of biochemical and physiological processes and the establishment of physiological values have rendered them [...] Read more.

Peripheral blood has been always used as the mirror of physiological status in a minimally invasive manner. In homeothermic vertebrates, different blood parameters have been correlated to a variety of biochemical and physiological processes and the establishment of physiological values have rendered them valuable indicators for research, diagnosis, and welfare status. Despite the volume of research in fish physiology and teleost significance for food security, information about the physiological values of minimally invasive biomarkers is still fragmented while there is a great need for such biomarkers for monitoring fish health, welfare, and factors that can impact their homeostasis. For the first time, we have focused on determining the physiological ranges of cholesterol, triglycerides, and total proteins in the plasma of gilthead sea bream (Sparus aurata) and detecting how size, diet, environment, and genetic background may influence these levels. A large heterogeneous dataset of 5318 healthy individuals of two different size classes (1–100 g; 101–200 g), dietary status (10 feeds and feeding regimes), and different genetic background (125 families), in combination with different geographic locations (GxE), was produced over a period of three years and analyzed to ensure a comprehensive representation in establishing the physiological range for these biomarkers. Dietary status and GxE introduced significant variations in the range of the physiological values of all biomarkers in both size classes. Triglyceride, total protein and cholesterol values did differentiate with age/size. Interestingly, all parameters responded to diet in a size-specific way, revealing their potential as biomarkers of dietary status. Full article

(This article belongs to the Special Issue Environmental Physiology of Aquatic Animals)

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17 pages, 6115 KB

Open AccessEditor’s ChoiceArticle

Black Sea Bass Centropristis striata Year Class Strength and Spatial Extent from Two Long-Term Surveys off the Southeast U.S. Atlantic Coast

by Julie L. Vecchio, Margaret W. Finch, Kevin R. Spanik, Amy Zimney and Tracey I. Smart

Fishes 2025, 10(2), 53; https://doi.org/10.3390/fishes10020053 - 28 Jan 2025

Viewed by 1788

Abstract

The Southeastern U.S. Atlantic coast (North Carolina to Florida, U.S.A.) has undergone considerable environmental change in recent decades, including increasing coastal water temperature and human development. The region is also home to a diverse suite of exploited reef fish species, including the southern [...] Read more.

The Southeastern U.S. Atlantic coast (North Carolina to Florida, U.S.A.) has undergone considerable environmental change in recent decades, including increasing coastal water temperature and human development. The region is also home to a diverse suite of exploited reef fish species, including the southern stock of black sea bass (Centropristis striata). The objective of the current study was to compare trends in black sea bass year class strength and central location captured by trawls (age 0) and traps (age 2) as well as compare those trends to regional bottom temperature. We found no correlation between age 0 and age 2 abundance when comparing the same year class, suggesting that the numbers of trawl-caught juveniles cannot predict the number of adults available to the fishery. Larger year classes observed in traps were correlated with centers of abundance farther south in the region, while smaller year classes corresponded with more northerly centers of abundance. In both trawls and traps, strong year classes occurred following years with below-average regional water temperatures, and a series of recent, weak year classes correspond with recent higher-than-average water temperatures. It is unclear whether correlations between shifting centers of abundance, year class strength, and regional bottom temperature indicate a range contraction for the southern stock of black sea bass or movement into areas previously inhabited by the northern stock of the species. Full article

(This article belongs to the Special Issue Biodiversity and Spatial Distribution of Fishes, Second Edition)

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21 pages, 789 KB

Open AccessEditor’s ChoiceReview

Pivotal Roles of Fish Nutrition and Feeding: Recent Advances and Future Outlook for Brazilian Fish Farming

by Aline Brum, Caio Magnotti, Mônica Yumi Tsuzuki, Elen Monique de Oliveira Sousa, José Luiz Pedreira Mouriño, Maurício Laterça Martins, Rafael Garcia Lopes, Roberto Bianchini Derner and Marco Shizuo Owatari

Fishes 2025, 10(2), 47; https://doi.org/10.3390/fishes10020047 - 27 Jan 2025

Cited by 12 | Viewed by 7498

Abstract

The aquafeed industry evolved alongside fish farming, utilizing scientific and technological advancements to incorporate a variety of feed additives, supplements, and alternative ingredients in the nutrition and feeding of fish in aquaculture. These advances played a significant role in improving the production, health, [...] Read more.

The aquafeed industry evolved alongside fish farming, utilizing scientific and technological advancements to incorporate a variety of feed additives, supplements, and alternative ingredients in the nutrition and feeding of fish in aquaculture. These advances played a significant role in improving the production, health, and welfare of farmed fish. Recent research in Brazil highlighted the importance of using fish feed additives, such as vitamins, minerals, and amino acids, to ensure that farmed fish receive all the necessary nutrients for growth and health. Functional additives can enhance the immune system, boosting disease resistance and promoting the overall health of fish. Antimicrobial and antiparasitic additives help prevent and treat infections and infestations, reducing the occurrence of disease outbreaks. Additionally, some additives improve feed digestibility, leading to better nutrient absorption and reduced feed requirements. Overall, nutritional strategies are essential for optimizing fish farming practices in Brazil and globally, promoting fish health and sustainability in the industry. This review emphasizes the significance of certain additives, supplements, and ingredients strategically incorporated into experimental feeds for research in Brazilian fish farming. It also underscores the necessity for ongoing research. There is a noticeable trend towards developing more sustainable and efficient feeds, which is essential for the future of sustainable aquaculture. The goal is to minimize environmental impacts while maintaining economic viability in aquaculture operations. Full article

(This article belongs to the Special Issue Pivotal Roles of Feed Additives for Fish)

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