Search Results (107)

This study evaluated the effects of alternative feed formulations on the proximate composition and lipid quality of gilthead sea bream (Sparus aurata) in a long-term feeding trial (May 2022–September 2023). Three isoenergetic and isoproteic diets were tested in replicate tanks: a fishmeal-based control (CTRL), a processed animal protein–based diet (PAP), and a diet including insect meal and microalgae oil (ALT). Diet pellet sizes were adapted to the fishes’ developmental stage. Proximate composition and fatty acid profiles were assessed in feed and in fish fillets, with 20 fish analyzed per dietary treatment. The human health lipid indices of the fillets were calculated. Virtual diets were reconstructed to estimate theoretical fatty acid intake across growth, based on feed composition and consumption. Partial least squares discriminant analysis (PLS-DA) revealed distinct clustering by diet. Fillets from all diets met European Food Safety Authority criteria for being high in omega-3 fatty acids, with some variation in EPA and DHA concentrations among formulations. The ALT diet showed a 15% higher EPA+DHA content and the greatest fish lipid quality (FLQ) values, even having the lowest polyunsaturated fatty acids (PUFA) intake from feed, partly due to its elevated lauric acid (C12:0) content, which may contribute to rapid energy mobilization and omega-3 preservation. PAP-fed fish showed the most balanced PUFA/SFA and n6/n3 ratios. These findings demonstrate the viability of sustainable feed alternatives for maintaining nutritional quality in gilthead sea bream, supporting aquaculture sustainability without compromising nutritional value. Full article

As aquaculture adopts more sustainable feed formulations, interest in functional feed additives has grown to help mitigate the health and performance challenges associated with low-marine-ingredient diets. This study evaluated the effects of dietary supplementation with a commercial blend of mono-, di-, and triglycerides of short- and medium-chain fatty acids (SCFAs and MCFAs; BalanGUT™ AQ P, BASF) on growth, health, and disease resistance to Vibrio anguillarum in juvenile gilthead sea bream (Sparus aurata) fed practical low fishmeal and fish oil diets. Over an 8-week trial, fish were fed diets containing 0.3%, 0.5%, or 1% of a glyceride blend of SCFAs and MCFAs (BalanGUT™ AQ P) or a Control diet without functional additive supplementation. Growth performance and feed utilization were not affected by the supplementation of SCFAs/MCFAs glycerides, although non-significant trends (p > 0.05) toward improved specific growth rate (up to 12%) and reduced feed conversion ratio (up to 17%) were observed in sea bream fed supplemented diets, particularly during the 4 initial weeks and at the highest inclusion level (1%). Moderate (0.5%) and high (1%) supplementation levels of SCFAs and MCFAs significantly improved survival following Vibrio anguillarum challenge, despite no significant changes being observed in general systemic innate immune markers, such as serum lysozyme or ACH50 activities. SCFAs/MCFAs supplementation, particularly at 0.3% or 0.5%, also modulated intestinal morphology, including thinner submucosa and smaller goblet cell area in the posterior intestine, suggestive of a more homeostatic mucosa and reduced basal inflammation when feeding a low-FM/FO-based diet. These results suggest that the protective effects of this SCFAs/MCFAs glyceride blend are mediated primarily through local rather than systemic immune modulation. Overall, this study supports the use of functional SCFAs and MCFAs glyceride blends as a functional strategy to promote resilience and health in fish fed sustainable, low-marine-ingredient diets. Full article

This review addresses the nutritional composition, health benefits, and claim conditions of aquaculture fish, focusing on gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax). Both species provide high-quality proteins, essential amino acids, and favorable lipid profiles, particularly long-chain omega-3 fatty acids, alongside minerals such as phosphorus and selenium, which meet EU criteria for several authorized nutrition and health claims. Evidence demonstrates that regular consumption supports cardiovascular, cognitive, and visual health, reduces inflammation, and contributes to better pregnancy and early childhood outcomes. Consumer skepticism toward aquaculture persists, often driven by perceptions of reduced nutritional quality, despite evidence that farmed fish provide nutritionally valuable proteins and beneficial lipids. Nevertheless, both species consistently meet the requirements for multiple nutrition and health claims, particularly those related to protein, omega-3 fatty acids, and selected minerals, allowing their effective use in labeling and consumer communication. Clear, evidence-based labeling of such claims is crucial to enhance acceptance and promote farmed fish as safe, sustainable, and health-promoting dietary choices. Full article

The increasing consumption of raw and minimally processed fish products has raised concerns regarding the risk of anisakiasis, the infection caused by ingesting larvae of the Anisakis genus. Freezing is currently the standard control measure; however, alternative non-thermal technologies are being explored to preserve product quality while ensuring safety. Several studies have investigated the impacts of high-pressure processing (HPP) on seafood products, but limited information is available about the minimum effective pressure required to achieve complete inactivation of Anisakis larvae while maintaining fillet quality. Moreover, no studies have evaluated the use of portable near-infrared (NIR) spectroscopy as a rapid tool to authenticate HPP-treated fish products. This study evaluated the efficacy of HPP in inactivating Anisakis spp. larvae in gilthead sea bream (Sparus aurata) fillets and investigated the impact of treatment on physicochemical quality parameters. In addition, the reliability of portable NIR spectroscopy coupled with chemometrics was assessed for rapid discrimination between treated and untreated samples. HPP treatments were applied with different pressure–time combinations, and the treatment at 200 MPa for 5 min was selected as the optimal treatment since it was able to achieve 100% larval inactivation. Quality evaluation showed significant changes in color (increase in L* values) and texture parameters, consistent with pressure-induced denaturation, while lipid oxidation remained within acceptable limits. NIR spectra analysis combined with chemometrics approach allowed discrimination between not treated and HPP-treated fillets with an overall accuracy of 98%. The results demonstrate that HPP at moderate pressure levels represents a promising alternative to freezing for Anisakis larvae inactivation in farmed sea bream, and that portable NIR spectroscopy may serve as a rapid, non-destructive tool for on-site verification of treatment. This combined approach could support the development of innovative control strategies in seafood safety management Full article

Sustainable expansion of global aquaculture relies on innovative alternative diets that reduce dependence on marine-derived ingredients. Poultry by-product meal (PBM) and insect meal have emerged as promising protein sources, yet their combined use under commercial farming conditions remains poorly explored. This study evaluated a plant-based finishing diet low in marine proteins and supplemented with 10% Hermetia illucens larvae meal (HIM) and 30% PBM (H10P30) and compared it with a conventional commercial diet (COM) in gilthead sea bream (Sparus aurata) reared on a land-based farm for 65 days. Health and welfare indicators, product safety, fillet quality, fatty acid profile, oxidative status, and consumer acceptance were assessed. Fish fed the H10P30 diet showed a significantly higher body weight and specific growth rate and a lowered feed conversion ratio than COM-fed fish. No external or internal lesions or liver histopathological alterations related to the H10P30 diet were observed. While the diet influenced the fatty acid profile of raw fillets, differences disappeared after cooking, except for a higher C22:6n-3 content in cooked H10P30 fillets. Sensory analysis penalised COM fillets due to the perceived hard texture and low juiciness. In summary, incorporating both PBM and HIM into a plant-based finishing diet serves as a viable feeding strategy for gilthead sea bream, contributing to improved feed sustainability. Full article

Fish host complex intestinal bacterial communities that contribute to a wide range of functions, from nutrient assimilation to modulation of the immune system. Understanding how environmental and host-related factors shape the fish gut microbiota is essential for advancing sustainable aquaculture practices. This study compared the intestinal microbiota of gilthead sea bream (Sparus aurata) between wild and aquaculture populations in western Greece using 16S rRNA gene amplicon sequencing targeting the V3–V4 region, combined with culture-based methods. The analysis was based on a 97% similarity threshold and included 141 gastrointestinal samples of fish collected at two aquaculture facilities and two wild fisheries, representing two different growth phases (150 g and 300 g body weight). High-throughput sequencing data revealed a clear separation of gut microbial communities according to origin (wild vs. aquaculture), geographic location, and body growth phase, with most wild fish groups exhibiting higher microbial diversity than their farmed counterparts, except for group MES_150 which showed similar or lower values. The gut microbiota was dominated by Pseudomonadota (53%), Bacillota (29%), Actinomycetota (7%), Deinococcota (5%), and Bacteroidota (4%). A shared core microbiome, comprising Psychrobacter, Staphylococcus, Geobacillus, Aeromonas, Enterobacter, Pantoea, Bacillus, and Acinetobacter, was detected across all populations. Wild fish were enriched in Psychrobacter, Aeromonas, and Photobacterium, while aquaculture fish displayed higher abundances of Vibrio, Allomeiothermus, and Staphylococcus. Network analysis revealed mostly mutually exclusive interactions in both groups but distinct patterns of co-occurrence, driven mainly by Paenibacillus, Enterobacter, and Staphylococcus in wild samples, and by Vibrio, Aeromonas, and Pseudomonas in farmed fish. Culture-based assays demonstrated greater diversity in wild fish, dominated by Pseudomonas, Staphylococcus, and Vibrio strains, in contrast to the frequent occurrence of Staphylococcus and Psychrobacter in aquaculture samples. The findings suggest that aquaculture practices significantly alter gut microbial community structure and reduce diversity, with potential implications for fish health and disease resistance. The identified core and differentially abundant taxa provide candidates for probiotic development to improve aquaculture sustainability. Full article

Genomic prediction has been increasingly applied in aquaculture selective breeding; however, systematic evaluations of prediction accuracy across multiple aquaculture species and analytical methods under a unified and comparable framework remain limited. In this study, we conducted a comprehensive comparative assessment of genomic prediction performance across four representative aquaculture species, including Atlantic salmon (Salmo salar), gilthead sea bream (Sparus aurata), common carp (Cyprinus carpio), and rainbow trout (Oncorhynchus mykiss), using ten genomic prediction models including GBLUP, Bayesian and machine learning methods. Prediction accuracy varied widely among species and models, ranging from 0.49 to 0.85, and was strongly associated with trait heritability. High-heritability traits consistently achieved higher prediction accuracies, with rainbow trout and common carp exhibiting the best overall performance (0.75–0.83 and 0.73–0.85, respectively), whereas Atlantic salmon and gilthead sea bream showed lower and more variable accuracies (0.49–0.61 and 0.49–0.66). No single model performed optimally across all species. Machine learning-based approaches achieved the highest prediction accuracy in specific cases but exhibited pronounced species-dependent variability, while GBLUP provided stable and well-calibrated predictions with consistently low bias. Incremental SNP feature selection further improved prediction accuracy by 2.8–4.2% in three species using only 0.54–9.64% of the available markers, whereas no improvement was observed for a low-heritability trait. These results show that genomic prediction performance is highly context-dependent and underscores the importance of jointly considering trait genetic architecture, population characteristics, model choice, and marker selection when optimizing genomic selection strategies in aquaculture breeding programs. Full article

In fish gut microbiome studies, there are no standardized protocols regarding sampling region or post-feeding time, nor clear consensus on whether analyses should target resident (autochthonous) or transient (allochthonous) bacteria. This study examined the dynamics and interactions of both microbial communities in the anterior and posterior intestine of farmed gilthead sea bream and evaluated the resident microbiome at 24 and 48 h post-feeding. Microbial DNA was sequenced using the Oxford Nanopore Technology platform. Data were analyzed through statistical and discriminant approaches, as well as a Bayesian network framework to assess bacterial interactions. Transient communities showed higher richness and diversity, regardless of intestinal section, suggesting a more specialized and stable microbial environment in the mucus layer. The two communities differed markedly in structure and composition. Variations associated with intestinal region were less pronounced, particularly for autochthonous bacteria, and post-feeding fluctuations in the resident microbiome were minimal. Functionally, results indicated relevant synergies between communities. Protein metabolism pathways were enriched in autochthonous bacteria, whereas allochthonous microorganisms contributed mainly to bile acid and carbohydrate metabolism. Overall, resident and transient bacteria constitute distinct communities in the gut of gilthead sea bream, with numerous genera present in both but most being differentially represented and interconnected. Full article

This study investigated the effectiveness of basil (Ocimum basilicum L.) extract obtained by hydrodistillation (EO) and lipid extract (LE) obtained via supercritical fluid extraction in preserving the quality of ground fish patties during refrigerated storage. Gilthead sea bream (Sparus aurata) patties were formulated with varying concentrations of EO and LE and evaluated over three days at 4 °C. The chemical composition of the extracts, analyzed by GC-MS, revealed linalool, eucalyptol, and τ-cadinol as dominant bioactive compounds, with EO richer in monoterpenes and LE in sesquiterpenes. Both extracts significantly reduced lipid oxidation (TBARS) and protein oxidation (thiol content), with the strongest antioxidative effect observed in patties containing 0.150 µL/g of LE. Color parameters (L*, a*, b*, ΔE) were moderately influenced, without adverse effects on product appearance. pH and water activity values remained stable across treatments, while total volatile basic nitrogen (TVB-N) levels confirmed delayed spoilage in extract-treated patties. Results highlight the potential of basil extracts, especially LE obtained by SFE, as effective natural antioxidants in fish-based products. These findings support the development of clean-label, health-promoting products tailored to individual needs, and show that ground fish porridge has promise as a viable material for the production of innovative seafood products. Full article

This study evaluated the combined effect of the modified atmosphere packaging (MAP1: 60% CO₂, 10% O₂/30% N₂ & MAP2: 40% CO₂, 30% O₂/30% N₂), and active packaging of oregano essential oil (1% v/w) used as a natural preservative, on the quality and shelf-life extension of fresh sea bream fillets. The samples were stored at four different temperatures (0, 4, 8, and 12 °C), and a microbiological analysis, pH measurements, and sensory evaluations were performed. In parallel, spectral data were obtained using three different spectroscopic sensors (two MultiSpectral Imaging devices and an FT-IR one), and nine different machine-learning regression models were applied to predict the microbiological counts. Oregano essential oil positively affected preservation, reducing microbial growth by 0.5 to 2 log CFU/g, and extending the fillets’ shelf life by up to 48 h based on sensory evaluation. Regarding the sensors’ data, the examined nine models exhibited encouraging results for the rapid microbiological assessment, with the FT-IR data showing the best performance for evaluating the microbiological population. Among the tested algorithms, the least Angle Regression (lars) achieved the best performance for both the flesh and skin datasets, with RMSE values of 0.6075 and 0.5953, MAE of 0.3008 and 0.4567, R² of 0.8858 and 0.7532, and accuracy of 87% and 91%, respectively. The Benchtop-MSI showed the best predictive performance for flesh (RMSE = 0.5926, MAE = 0.4876, R² = 0.7338, and Accuracy = 92%), while the artificial neural network (nnet) performed best for skin (RMSE = 0.6761, MAE = 0.5247, R² = 0.6560, and Accuracy = 84%). Regarding the Portable-MSI, the artificial neural network model gave the highest accuracy for flesh (RMSE = 0.5908, MAE = 0.4663, R² = 0.5903, and Accuracy = 87%), whereas principal component regression was the most effective for skin (RMSE = 0.6600, MAE = 0.5413, R² = 0.5534, and Accuracy = 83%). Full article

Matrix metalloproteases (MMPs) are zinc-dependent endopeptidases that are critical for extracellular matrix (ECM) remodeling, with key roles in tissue development and repair, and immune responses. Despite their evolutionary and functional importance, the diversification and regulatory dynamics of MMPs genes in teleosts remain poorly understood. This study investigates the evolutionary history of MMPs with collagenolytic activity in the vertebrates with an emphasis on teleosts. Using comparative genomics and phylogenetics we identified conserved single-copy mmp2 and mmp9 genes and duplicated mmp11 and mmp13 paralogs in all non-salmonid teleosts. Phylogenetic and synteny analyses suggest that mmp11 paralogs originated from the teleost-specific genome duplication (TSGD), whereas the origin of mmp13 paralogs originated from a more complex evolutionary scenario. Protein domain analysis confirmed conserved catalytic motifs across species, supporting functional retention. The expression patterns of paralog genes were studied in two model marine teleosts, the Sparus aurata (gilthead sea bream) and Dicentrarchus labrax (European sea bass). Developmental and adult tissue transcriptome analyses revealed three major expression patterns among the paralogs: similar expression, stage-specific or tissue-specific expression. The overall data point to varied evolutionary dynamics of MMP genes in the teleosts, tracing their origin to different whole-genome duplication events. Expression profiles on paralog genes in model teleosts suggest regulatory sub-functionalization as the most possible fate of retained MMPs paralogs in teleosts following whole-genome duplication. Full article

This study developed and characterized zein-based edible films enriched with curcumin as natural pH-sensitive indicators for monitoring fish freshness. Colorimetric films were prepared with different curcumin concentrations (1–7% wt) and evaluated for physicochemical, mechanical, optical, and antioxidant properties. Increasing curcumin content reduced water vapor permeability (0.085–0.110 g·mm/m²·h·kPa), lowered water contact angles (<90°), and enhanced hydrophilicity. Films exhibited high brightness, with decreased a* and increased b* values, while light transmission decreased, improving UV barrier properties. Colorimetric response (ΔE*) across pH 3–10 was more pronounced at higher curcumin levels, confirming pH-sensitivity. Antioxidant activity significantly increased with curcumin loading (up to 24.18 µmol Trolox/g). Mechanical analysis revealed decreased tensile strength but improved elongation at break, bursting strength, and deformation, supported by SEM images showing more homogeneous, micro-porous structures at 7% curcumin. Zein films containing 7% (wt) curcumin (Z/CR7) were applied to gilthead sea bream (Sparus aurata) fillets stored at 4 °C for 13 days. Results showed lower TBARS and TVB-N values in Z/CR7 compared to the control, indicating delayed lipid oxidation and spoilage. Colorimetric changes in the films corresponded with fish freshness deterioration, providing a clear visual indicator. Microbiological results supported chemical findings, though antimicrobial effects were limited. Curcumin-enriched zein films demonstrated strong potential as intelligent, biodegradable packaging for real-time monitoring of seafood quality. Full article

The revalorization of animal by-products, such as porcine blood, is a key strategy for sustainable aquaculture and circular economy practices. This study aimed to fill the existing knowledge gap on the effects of spray-dried porcine blood hydrolysate (PBSH), assessing its potential as a functional feed ingredient for gilthead sea bream. Two practical diets were formulated: a control diet containing 5% blood meal, and a PBSH diet including 5% PBSH previously characterized in vitro. The results indicated that the PBSH diet promoted lower hepatosomatic index, a down-regulation of key hepatic lipogenic enzymes (scd1b, hl, lpl), and a better stress condition with lower circulating levels of glucose and cortisol and a reduction in aggressive attacks. Positive findings were also achieved in energy management, obtaining lower metabolic rates along with an enhanced swimming performance (20% increase in the critical speed) and a quicker weigh recovery after a fasting period. The PBSH diet also shaped the intestinal bacterial composition, determining a redistribution of abundant genera including Aureimonas and Halomonas. Ultimately, this study demonstrated that PBSH would act as a functional ingredient capable of enhancing fish energy management and resilience in the face of stressful events, exhibiting a transient transcriptional modulation, yet persistent physiological and welfare benefits. Full article

Intestinal microbiota populations are constantly shaped by both intrinsic and extrinsic factors, including diet, environment, and host genetics. As a result, understanding how to assess, monitor, and exploit microbiome–host interplay remains an active area of investigation, especially in aquaculture. In this study, we analyzed the taxonomic structure and functional potential of the intestinal microbiota of European sea bass and rainbow trout, incorporating gilthead sea bream as a final reference. The results showed that the identified core microbiota (40 taxa for sea bass and 20 for trout) held a central role in community organization, despite taxonomic variability, and exhibited a predominant number of positive connections (>60% for both species) with the rest of the microbial community in a Bayesian network. From a functional perspective, core-associated bacterial clusters (75% for sea bass and 81% for sea bream) accounted for the majority of predicted metabolic pathways (core contribution: >75% in sea bass and >87% in trout), particularly those involved in carbohydrate, amino acid, and vitamin metabolism. Comparative analysis across ecological phenotypes highlighted distinct microbial biomarkers, with genera such as Vibrio, Pseudoalteromonas, and Paracoccus enriched in saltwater species (Dicentrarchus labrax and Sparus aurata) and Mycoplasma and Clostridium in freshwater (Oncorhynchus mykiss). Overall, this study underscores the value of integrating taxonomic, functional, and network-based approaches as practical tools to monitor intestinal health status, assess welfare, and guide the development of more sustainable production strategies in aquaculture. Full article

The aquaculture industry has experienced considerable growth in recent decades, stimulating research into sustainable and functional feed formulations, mainly related to using high-quality, safe, and environmentally friendly feed ingredients. The employment of immunomodulatory additives is a promising strategy to enhance fish health and performance. In this study, the effects of the ghrelin analog GHRP-6 peptide included in the diet (500 µg/kg of feed) on the endocrine and immune responses of Sparus aurata following Incomplete Freund’s adjuvant (IFA) treatment were assessed. After 97 days, fish were intraperitoneally injected with 100 µL of saline solution or IFA/100 g fish and sampled 72 h post-injection. Our results indicated that fish fed GHRP-6 maintained stable plasma levels of lactate, triglycerides, and cortisol after IFA treatment, in contrast to control-fed fish, which showed significant metabolic stress. Circulating immunoglobulin levels enhanced significantly in the GHRP-6/IFA group, suggesting a stimulated humoral immune response. Transcriptomics analysis revealed that the anterior intestine was the most responsive tissue, with upregulation of il10, il15, il34, and mx1, indicating mucosal immune activation. In the spleen, GHRP-6-fed fish increased il8, il10, and ighm expression, highlighting a balanced pro- and anti-inflammatory response and support for adaptive immunity. Multivariate analysis confirmed that dietary GHRP-6 modulates immune gene expression in a tissue- and stimulus-specific manner, without inducing histological alterations in the intestine or spleen. Taken together, these preliminary results indicate that this peptide is a viable and safe dietary supplement to improve immune resilience and increase the production efficiency of S. aurata and suggest a protective effect on the fish’s immune system in this species. Full article