Search Results (311)

The use of eco-organic ingredients as a source of protein in aquaculture diets needs important attention due to the growing demand for organic seafood products. The present study evaluated the effects of fish meal substitution by different organic ingredients on the growth, body composition, retention efficiency, enzyme activity, and nutrient digestibility of white shrimp Penaeus vannamei. The four dietary formulations tested were formulated with organic ingredients and the fish meal was replaced by the following organic protein meals: Iberian pig viscera meal (PIG), trout by-product meal (TRO), insect meal (FLY), and organic vegetable meal (WHT), in addition to a control diet (CON) that included 15% fish meal. A growth trial was carried out for 83 days, raising 1 g shrimp to commercial size (20 g). Shrimp were stocked at 167 shrimp/m³ (15 individuals per 90 L tank). The results showed that the growth obtained by shrimp fed with TRO (19.27 g) and PIG (19.35 g) were similar in weight gain to the control diet (20.76 g), while FLY (16.04 g) and WHT (16.73 g) meals resulted in a significant lower final weight. The FLY diet showed significantly lower protein digestibility (68.89%) compared to the CON, PIG, TRO, and WHT diets, and significantly higher trypsin activity (0.17 mU/g) compared to shrimp fed with the PIG, TRO, and WHT diets. Shrimp fed with WHT have a significantly lower body weight percentage of protein (19.69%) than shrimp fed with the WHT and TRO diets, and some significant differences in dietary aminoacidic levels affecting amino acid body composition. These results indicate that Iberian pig viscera and trout by-product meal can successfully replace fish meal in Pacific white shrimp aquaculture. Full article

Seafood contamination by heavy metals is a growing public health concern, particularly in regions like Tunisia where seafood is a major dietary component. This study assessed concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the muscle tissue of the red shrimp Parapenaeus longirostris, collected in 2023 from four coastal regions: Bizerte, Monastir, Kerkennah, and Gabes. Metal analysis was conducted using flame atomic absorption spectroscopy. This species was chosen due to its ecological and economic importance. The study sites were chosen based on their differing levels of industrial, urban, and agricultural influence, providing a representative overview of regional contamination patterns. Mean concentrations were 1.04 µg/g for Zn, 0.59 µg/g for Cu, 1.56 µg/g for Pb, and 0.21 µg/g for Cd (dry weight). Pb was the most prevalent metal across sites. Statistically significant variation was observed only for Cu (p = 0.0334). All metal concentrations were below international safety limits set by FAO/WHO and the European Union. Compared to similar studies, the levels reported were similar or slightly lower. Human health risk was evaluated using target hazard quotient (THQ), hazard index (HI), and cancer risk (CR) values. For adults, THQ ranged from 5.44 × 10⁻⁶ to 8.43 × 10⁻⁴, while for children it ranged from 2.40 × 10⁻⁵ to 3.72 × 10⁻³. HI values were also well below 1, indicating negligible non-carcinogenic risk. CR values for Cd and Pb in both adults and children fell within the acceptable risk range (10⁻⁶ to <10⁻⁴), suggesting no significant carcinogenic concern. This study provides the first field-based dataset on metal contamination in P. longirostris from Tunisia, contributing valuable insights for seafood safety monitoring and public health protection. Full article

Global marine coastal aquaculture increased by 6.7 million tons in 2024, with whiteleg shrimp (Penaeus vannamei) dominating crustacean production. However, reliance on a single species raises sustainability concerns, particularly in the face of climate change. Diversifying shrimp farming by cultivating native species, such as the European brown shrimp (Crangon crangon), presents an opportunity to develop a sustainable blue bioeconomy in Europe. C. crangon holds significant commercial value, yet overexploitation has led to population declines. Integrated Multi-Trophic Aquaculture (IMTA) offers a viable solution by utilizing fish farm wastewater as a nutrient source, reducing both costs and environmental impact. Research efforts in Germany and other European nations are exploring IMTA’s potential by co-culturing shrimp with species like sea bream, sea bass, and salmon. The physiological adaptability and omnivorous diet of C. crangon further support its viability in aquaculture. However, critical knowledge gaps remain regarding its lipid metabolism, early ontogeny, and reproductive biology—factors essential for optimizing captive breeding. Future interdisciplinary research should refine larval culture techniques and develop sustainable co-culture models. Expanding C. crangon aquaculture aligns with the UN’s Sustainable Development Goals by enhancing food security, ecosystem resilience, and economic stability while reducing Europe’s reliance on seafood imports. Full article

Copper pyrithione (CuPT), an emerging biocide used in ship antifouling coatings, may accumulate in marine sediments and pose risks to non-target organisms. However, current research on CuPT toxicity remains limited. Litopenaeus vannamei, one of the world’s most important aquaculture shrimp species, relies heavily on its hepatopancreas for energy metabolism, detoxification, and immune responses. Due to their benthic habitat, these shrimps are highly vulnerable to contamination in sediment environments. This study investigated the toxicological response in the hepatopancreas of L. vannamei exposed to CuPT (128 μg/L) for 3 and 48 h. Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) fluorescence staining revealed increased apoptosis, deformation of hepatic tubule lumens, and the loss of stellate structures in the hepatopancreas after CuPT 48 h exposure. A large number of differentially expressed genes (DEGs) were identified by transcriptomics analysis at 3 and 48 h, respectively. Most of these DEGs were related to detoxification, glucose transport, and immunity. Metabolomic analysis identified numerous significantly different metabolites (SDMs) at both 3 and 48 h post-exposure, with most SDMs associated with energy metabolism, fatty acid metabolism, and related pathways. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of metabolomics and transcriptome revealed that both DEGs and SDMs were enriched in arachidonic acid metabolism, fatty acid biosynthesis, and glycolysis/gluconeogenesis pathways at 3 h, while at 48 h they were enriched in the starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, and galactose metabolism pathways. These results suggested that CuPT disrupts the energy and lipid homeostasis of L. vannamei. This disruption compelled L. vannamei to allocate additional energy toward sustaining basal physiological functions and consequently caused the accumulation of large amounts of reactive oxygen species (ROS) in the body, leading to apoptosis and subsequent tissue damage, and ultimately suppressed the immune system and impaired the health of L. vannamei. Our study elucidates the molecular mechanisms of CuPT-induced metabolic disruption and immunotoxicity in L. vannamei through integrated multi-omics analyses, providing new insights for ecological risk assessment of this emerging antifoulant. Full article

Investigating the volatiles isolated from a commercial spirulina (Arthrospira platensis) dietary supplement by gas chromatography–olfactometry (GC–O) in combination with an aroma extract dilution analysis (AEDA) resulted in 29 odor events with flavor dilution (FD) factors between 8 and 2048. Identification experiments, including various offline and online fractionation approaches, led to the structure assignment of 30 odorants, among which the most potent were sweaty 2- and 3-methylbutanoic acid (FD 2048), roasty, earthy, shrimp-like 2-ethyl-3,5-dimethylpyrazine (FD 2048), vinegar-like acetic acid (FD 1024), and floral, violet-like β-ionone (FD 1024). Static headspace dilution analysis revealed sulfuric, cabbage-like methanethiol (FD factor ≥ 32) as an additional potent odorant. In summary, 31 important spirulina odorants were identified in this study, and 14 were reported for the first time as spirulina constituents. Our data will provide a basis for future odor optimization of spirulina-based food products. Full article

Crustins are a family of cysteine-rich antimicrobial peptides (AMPs), predominantly found in crustaceans, and play important roles in innate immunity. However, among the many reported crustins, few studies have explored their immunomodulatory functions. In this study, we investigated the immune function of a type I crustin (LvCrustinIa-2) in Litopenaeus vannamei, with particular emphasis on comparing the roles of its different domains. LvCrustinIa-2 possesses cationic patchy surface and amphipathic structure, and its expression was significantly induced in hemocytes after pathogen challenge. Both the recombinant LvCrustinIa-2 (rLvCrustinIa-2) and its whey acidic protein (WAP) domain (rLvCrustinIa-2-WAP) exhibited significant inhibitory activities against the tested Gram-positive bacteria. They also showed binding affinity not only for Gram-positive bacteria but also for Gram-negative bacteria. Furthermore, rLvCrustinIa-2 induced membrane leakage and structure damage in the target bacteria. Notably, chemotaxis assays revealed that rLvCrustinIa-2 and the synthetic cysteine-rich region (LvCrustinIa-2-CR) significantly enhanced the chemotactic activity of shrimp hemocytes in vitro. Knockdown of LvCrustinIa-2 triggered significant transcriptional activation of genes involved in calcium transport, inflammation, redox regulation, and NF-κB pathway. Taken together, these findings elucidate the distinct roles of the cysteine-rich region and WAP domain in type Ia crustin and provide the first evidence of a crustacean AMP with chemotactic and immunomodulatory activities. Full article

Biofloc technology (BFT) represents a promising approach among sustainable options for the sustainable intensification of shrimp aquaculture, helping to mitigate environmental impacts while maintaining production yields. This study evaluated the effects of stocking density (200, 400, 600, and 800 ind/m³) on the water quality, nitrogen dynamics, and production performance of Penaeus vannamei in BFT systems with limited water exchange (<10%). During an eight-week production-scale trial, water quality exhibited density-dependent deterioration, with TAN and NO₂⁻-N peaks increasing from 0.4 to 2.3 mg/L and 1.0 to 4.2 mg/L, respectively, as density rose from 200 to 800 ind/m³. Concurrently, DO and pH declined significantly from 6.7 to 5.1 mg/L and 7.6 to 7.3, respectively. Production performance revealed critical trade-offs: while yield rose from 3.62 to 9.09 kg/m³, individual growth metrics declined, including harvest body weight (19.14 to 14.12 g), size variation (14.03% to 23.90%), and survival rate (94.6% to 79.8%). Quadratic regression analysis and response surface analysis identified 400~600 ind/m³ as the optimal density range, achieving balanced outcomes: yield (6.74~8.43 kg/m³), harvest body weight (16.72~18.03 g), survival rate (84.0%~93.5%), and feed conversion ratio (1.14~1.22). These findings provide actionable guidelines for optimizing stocking density in commercial BFT systems, highlighting the importance of balancing productivity with environmental sustainability under limited water exchange. Full article

The Pacific white shrimp, Litopenaeus vannamei (L. vannamei), is an important aquaculture species, yet the molecular mechanisms underlying its sex differentiation and gonadal development remain poorly understood. A deeper understanding of these processes is critical for advancing broodstock quality and enabling unisex breeding strategies. While previous studies have focused on gene expression differences between females and males, structural differences in transcriptomic regulation between sexes have been largely overlooked. Here, we present a comprehensive full-length transcriptome analysis of L. vannamei testis and ovary, identifying 830 and 690 novel genes, respectively, and over 6000 new isoforms. Notably, we discovered extensive alternative splicing (AS) events, with the cartilage oligomeric matrix protein-like gene exhibiting over 300 AS isoforms in the ovary compared to only 2 in the testis, suggesting a potential role in ovarian development. Furthermore, sex-determining genes such as Fem-1a, Fem-1c, and Sxl were found to produce AS isoforms exclusively in ovarian tissue. We also identified three germ cell development-associated genes—MAD2-like, RAD51-like, and Su(dx)-like—that undergo distinct AS events in gonadal tissues, leading to sex-specific structural domain alterations. These findings highlight the complexity of AS-mediated post-transcriptional regulation in L. vannamei and provide novel insights into the molecular mechanisms governing sex differentiation and gonadal development. Full article

Histological techniques are essential for studying small crustaceans’, such as Neocaridina shrimp, anatomy and physiology. However, their small size and rapid tissue autolysis present challenges for fixation and processing. This study aimed to optimize histological methods for Neocaridina shrimp by evaluating different protocols for fixation, decalcification, and enzymatic digestion. Shrimp were fixed using 10% neutral-buffered formalin (NBF) and Bouin’s or Davidson’s fluid with or without modifications such as trypsin digestion, decalcification, or abdomen removal. Tissue preservation, section quality, and staining properties were assessed. Davidson’s fluid consistently gave generally acceptable fixation results, with minimal autolysis and good tissue preservation. Trypsin digestion increased tissue damage and autolysis, particularly in the liver and pancreas. Decalcification improved the quality of the sections; however, it increased autolysis and resulted in less specific staining. The optimal protocol involved the removal of the abdomen, followed by fixation in Davidson’s fluid and decalcification, which resulted in rapid penetration of the fixative, minimal autolysis, and a beneficial effect on staining. This study highlights the importance of adapting histological methods to the specific characteristics of small crustaceans and provides a basis for future research on Neocaridina shrimp. Implementing these optimized techniques will improve the quality and reliability of histological analyses in crustacean research, deepening the understanding of their biology and facilitating their use as model organisms in various scientific fields. Full article

Research on the trophic transfer of trace elements in food chains, particularly toxic elements like mercury (Hg) and essential elements like selenium (Se), is crucial for understanding their impact on human health. In this work, we assessed the transfer of Hg and Se in the blue shark (Prionace glauca), a top predator with economic importance. Muscle samples from sharks, as well as their main prey (squid, red shrimp, sardine, and mackerel), were analyzed for Hg and Se concentrations. The Hg levels of sharks were below the recommended legal limit for seafood consumption in Mexico (1 µg·g⁻¹ ww), while Se levels were significantly lower than previously reported for the species. Biomagnification was evaluated in this species by calculating biomagnification factors (BMF) for Hg and Se based on predator-prey element concentrations. Hg showed a BMF of 2.8, indicating biomagnification, while Se had a BMF of 0.2, suggesting biodilution. Trophic transfer factor models supported these findings, showing a positive correlation of Hg concentration with trophic level and a negative correlation with Se. However, while a hazard quotient under one does not pose a risk for consumption, a Se:Hg molar ratio under one estimated in the muscle tissue indicates that Hg levels along this food web should be approached with caution. Full article

White spot syndrome virus (WSSV) has emerged as a significant threat to global shrimp aquaculture, causing economic losses because of its rapid spread and high mortality rates. This study aims to elucidate the genetic and evolutionary dynamics of WSSV through a comprehensive genome analysis. Utilizing 27 complete genome sequences sourced from public databases, this study investigates the genetic variability, potential recombination events, and evolutionary patterns of WSSV. Our results identified multiple genomic deletions, 14 novel single-nucleotide polymorphism sites, and variable number tandem repeats across different strains, underscoring the virus’s genetic diversity. A recombination event between freshwater and marine strains highlights a complex transmission pathway, potentially facilitated by aquaculture practices. A phylogenetic tree constructed using ancestral genes suggests that WSSV originated in Southeast Asia and subsequently globally spread, influenced by both natural and anthropogenic factors. Genomic shrinkage of the virus occurred in time series, while the host’s viral infection induced transposon transposition and insertion into the earlier virus genome to provide a basis for genomic shrinkage. Our research emphasizes the importance of advanced molecular characterization and evolutionary models of the virus in understanding the spread of viral pathogens in aquaculture environments. Full article

In this study, we aimed to investigate the occurrence of rare earth elements (REEs) in commonly consumed foods and assess the dietary exposure risks among different age groups in Zhejiang Province. The results showed that tea and shrimp had the highest REE detection rates, reaching 100%. Of all the food categories examined, tea exhibited the highest REE concentrations, significantly exceeding those in other foods. This may be attributed to differences in moisture content, root absorption mechanisms, and processing methods. The concentration pattern of REEs in all samples occurred in the following order: cerium > lanthanum > yttrium > neodymium > neodymium > scandium > praseodymium > gadolinium > dysprosium. The light REEs/heavy REEs (HREEs) ratio was consistently > 2 but remained lower than the ratios observed in the soil and sediments, indicating a potential risk of HREE enrichment. Dietary exposure assessments revealed that the total REE intake among Zhejiang residents was below the established safety threshold (51.3 µg/kg BW/day), with children experiencing the highest exposure (3.71 µg/kg BW/day), primarily due to their lower body weight. In the assessment of individual rare earth elements, Ce exposure in children aged ≤ 6 years exceeded the toxicological reference value. However, this threshold was established based on studies in pregnant and lactating populations and might not be directly applicable to young children. Therefore, overall dietary exposure to individual REEs remains within safe limits. REE exposure from tea consumption did not pose a health risk, even for habitual tea drinkers. These findings underscore the importance of continuous monitoring of REE accumulation in food and additional research on the potential long-term health effects, even though the current exposure levels of REEs are below the established safety limit. This is especially important considering the bioaccumulative nature of REEs and the limited paucity of toxicological data, particularly in vulnerable populations. Full article

The blue crab Callinectes sapidus Rathbun, 1896 is native to the western coast of the Atlantic Ocean. Although its arrival to the Mediterranean was probably due to ballast water, this species has several characteristics that have enabled it to successfully invade countless localities in the Mediterranean and the Black Sea. Little is known about its feeding habits and ecosystem impacts in the Mediterranean basin. This study aimed to provide information on the natural diet of C. sapidus by comparing the stomach contents of specimens caught in different seasons and habitats of the SE Iberian Peninsula (hypersaline waters in Mar Menor Lagoon and brackish waters in Guardamar Bay). This study also tested whether gender influences prey selection and if ovigerous females exhibit limited feeding activity. Regarding the frequency of occurrence, the results indicated that in Mar Menor Lagoon the most frequently consumed prey were Crustacea (60%), followed by fish (57%) and Mollusca (29%), whilst in Guardamar Bay, Mollusca (40%), sediment (32%), algae (24%) and Crustacea (24%) were dominant. It has been determined that this species predates heavily on Mediterranean shrimp Penaeus kerathurus, an economically important shrimp species in the lagoon area. Analysis using a generalised linear model indicated that sex, season and size class were factors that significantly influenced the stomach content weight. Furthermore, non-ovigerous females had significantly fuller stomachs than ovigerous individuals. Since the population of Callinectes sapidus tends to increase in the Mediterranean basin, monitoring of its feeding ecology is recommended to determine its impact on the ecosystem. Full article

Salinity serves as an important environmental factor in ecosystems, driving the evolution of adaptive strategies in euryhaline species. The Pacific white shrimp, Litopenaeus vannamei, is a representative euryhaline species. However, the molecular mechanisms, particularly the roles of cis-regulatory elements, remain elusive in penaeid shrimp. This study tackles this gap by subjecting L. vannamei to a gradual reduction in salinity from 30‰ to 3‰, and then applying ATAC-seq and RNA-seq techniques to dissect the cis-regulation mechanisms underlying low salinity adaptation. A key finding reveals a positive correlation between chromatin accessibility and gene expression, with 36.8% of differentially expressed genes directly associated with changes in chromatin accessibility. The cis-regulation of many osmoregulation-related pathways, such as betaine synthesis and PI3K-Akt signaling pathways, appeared to be a crucial strategy for salinity adaptation in shrimp. By analyzing differentially accessible regions under low salinity stress, we uncovered two known and seven novel candidate transcription factors (TFs) that may play pivotal roles in salinity adaptation. We further conducted a comprehensive analysis of these TFs, including their functions, expression profiles, consensus TFBS motifs, and the functional enrichment and expression profiles of their targeted genes. This study elucidates a complex cis-regulatory network that enables exceptional salinity tolerance in L. vannamei, which provides a foundation for the refinement of genetic breeding programs and desalination aquaculture for penaeid shrimp. Full article

High concentrations of ammonia nitrogen could result in the death of aquatic animals and cause a huge economic loss in the aquaculture industry. However, the metabolic responses to acute ammonia nitrogen stress remain largely unknown in Penaeus monodon. In this study, we first investigated the histological change in tissues in Penaeus monodon under 96 h acute ammonia nitrogen stress. The result of the paraffin section showed that acute ammonia nitrogen stress induced severe epithelial detachment and lumen dilatation of the hepatopancreas, swollen and hemocyte infiltration of the gills, and mucosa exfoliation and shortened villi of the intestine in Penaeus monodon, suggesting the impairment of the normal physiological function in these tissues. We next examined the change in the metabolic product in the plasma and the enzyme activity in the hepatopancreas after ammonia nitrogen stress. Upon ammonia stress, both the concentration of ammonia and urea nitrogen significantly increased, while there was no significant increase in the concentration of uric acid, which is consistent with the results that the enzyme activity of glutamine synthetase (GS), glutamate dehydrogenase (GDH), and aspartate transaminase (GOT) became significantly elevated and the enzyme activity of adenosine deaminase (ADA) in the purine metabolism pathway significantly decreased after ammonia stress, suggesting that shrimp could convert excessive ammonia to urea for ammonia detoxification through the ammonia–nitrogen metabolism pathways. Interestingly, we also observed a significant increase in superoxide dismutase (SOD) activity, suggesting a potential role of this antioxidant enzyme in the clearance of reactive oxygen species (ROS) induced via ammonia stress. Moreover, we found that acute ammonia nitrogen stress inhibited the enzyme activity of caspase 3 and caspase 8, suggesting an important role of apoptosis in protecting Penaeus monodon against acute ammonia stress. Overall, our findings revealed that Penaeus monodon may employ metabolic and purine pathways and undergo oxidative stress and apoptosis for ammonia detoxification under ammonia nitrogen stress, thus providing new insight into the metabolic response of shrimp to acute ammonia stress. Full article