Dicentrarchus Labrax Research Articles

This preliminary study investigates the impact of dietary supplementation with 2 mL/kg of either lemongrass (Cymbopogon citratus) or chamomile (Matricaria chamomilla) essential oils on the welfare of European seabass. To simulate typical operational stress, the fish (520 days post-hatching; 156.48 ± 25.05g) were subjected to a 15-min acute stressor, mimicking offshore sampling for biometric measurements, on days 15 and 33 of the feeding trial. Our results showed that these additives did not cause any signs of disease, toxicity, or mortality. They revealed significant effects of these essential oils (p < 0.05), particularly the lemongrass-enriched diet, on fish appetite and daily feed intake, as well as on growth performance (weight gain per month, specific growth rate, and thermal growth coefficient) and feed utilization (condition factor, feed conversion ratio, and protein efficiency ratio). These parameters progressively improved over the duration of administration (p < 0.001). Positive effects were observed on organosomatic indices, with improvements in the hepatosomatic index and a reduction in the visceral fat index. Furthermore, these oil-enriched diets significantly improved total protein levels and hematocrit percentages (p < 0.001). This increase persisted over time (p < 0.01) and was not affected by stress induced by the sampling operation. Cortisol, lactate, and glucose levels fluctuated depending on the diets and duration of administration, but remained within normal ranges for healthy fish. There was also individual variability among fish within the same feeding group regarding these zootechnical and physiological responses. Finally, the bacterial load of Enterobacteriaceae, Enterococci, and total flora in the intestinal and skin mucus of seabass decreased after one month of feeding with essential-oil-based diets, particularly with chamomile. In conclusion, dietary inclusion of lemongrass and chamomile essential oils appears to offer promising anxiolytic and immunomodulatory benefits. However, further investigations are warranted to confirm their viability as a nutritional strategy to enhance the welfare and resilience of D. labrax in Mediterranean aquaculture.

It's not just synthetic microplastics: Multi-tissue approach reveals a wide range of transcriptional changes in European seabass exposed to viscose-rayon microfibres.

Recreational fishing is an increasingly popular leisure activity on a global scale, with catches that may surpass those of commercial fisheries. However, the lack of comprehensive and standardized data hinders accurate assessment of its ecological impact. This study investigates the species composition across three variables including fishing modalities (shore angling, boat angling, and spearfishing), zone and season along the NW Mediterranean coast. Species identification and number of individuals caught data were obtained through onsite surveys conducted between 2020 and 2023. The results reveal significant differences in catch composition among modalities, as well as across spatial and seasonal scales. However, modality exhibited the greatest differentiation in catch composition compared to the other two variables. Then, regarding modality, boat angling and spearfishing yield the highest catch rates but boat angling had the greatest number of species (i.e., 69). However, species composition characterized the catches of each modality. Specifically, Dicentrarchus labrax was more frequently fished by shore anglers, Loligo vulgaris by boat anglers, and Mullus surmuletus by spearfishers. Currently, there is a need to develop and reinforce marine recreational fisheries sustainable management practices at a regional scale. In the study area, our findings suggest that fishing modality is the main driver to consider when developing sustainable management strategies and the conservation of coastal marine biodiversity.

BackgroundThe unique feeding behavior of Siniperca chuatsi (S. chuatsi), which exclusively consumes live fry and rejects dead fry, severely limits the development of its aquaculture industry. This rejection of dead fry likely stems from an aversion to necromones (death-associated odors). Although a subset of trace amine-associated receptors (TAARs) containing key conserved residues (Asp3.32 and/or Asp5.42) are implicated in detecting amine-related odors, the taar gene members in S. chuatsi and their responsiveness to necromones remain unexplored.ResultsIn this study, we found that the aversion of S. chuatsi to dead prey is associated with necromones. Furthermore, we identified 68 taar family members in the S. chuatsi genome, distributed across six chromosomes, with 36 tandem duplication events generating 54 duplicated genes. Phylogenetic analysis classified taars into two classes, Class I and Class III, with a total of eight subfamilies. Synteny analysis revealed low synteny between the taars of S. chuatsi and Dicentrarchus labrax, with only 12 pairs of genes showing syntenic relationships. Protein sequence analysis demonstrated that taars contain amine recognition sites, N-glycosylation, and conserved cysteine structures, with high conservation and purifying selection observed within subfamilies. Subcellular localization revealed that TAARs are localized to the cell membrane and nucleus. Transcriptome data indicated that 61 taars are expressed in the olfactory epithelium, while only 19 are expressed in the brain. The response of representative taars to putrescine and cadaverine was divergent when comparing olfactory and brain tissues.ConclusionsThis study systematically identified the taar gene family in S. chuatsi, analyzing their evolutionary relationships, protein structures, subcellular localization, expression profiles in olfactory and brain tissues, and the response of selected TAARs to necromones (cadaverine and putrescine). This work establishes a foundation for further investigation into TAAR-mediated death odor recognition in S. chuatsi.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12864-025-12142-3.

Transcriptional profiling of receptor-transporting protein 3 variants in European sea bass and gilthead seabream suggests divergent roles.

This study aimed to determine the presence and characteristics of microplastics (MPs) in six commercially important fish species in Samsun city of, the Middle Black Sea Region: rainbow trout–Turkish salmon (Oncorhynchus mykiss), European seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata), red mullet (Mullus barbatus), horse mackerel (Trachurus mediterraneus), and whiting (Merlangius merlangus). The digestive systems of each species were examined, and MPs were classified according to their morphology, size, color, and polymer type. The analysis revealed that the number of MPs per individual ranged from 4.73 ± 1.13 to 9.26 ± 2.18, with the highest value found in rainbow trout and the lowest in whiting. MPs smaller than 100 µm were dominant (48.9%), and fiber (45.7%) and fragment (36.5%) types were the most common morphologies observed. Black and white/transparent colors were prominent in terms of color distribution, and ATR-FTIR analysis showed a dominance of widely used consumer plastics, such as polypropylene (PP, 31.3%) and polyethylene (PE, 23.9%). Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS) results confirmed the presence of irregular, fibrous, and fragmented structures at microscopic scale, consistent with microplastic morphology. These findings indicate a potential risk of microplastic pollution in the region for both marine biota and human consumption. The study fills a significant data gap regarding the Middle Black Sea ecosystem and provides a foundation for future monitoring and risk assessment research.

Environmental changes can induce epigenetic modifications, influencing gene expression, phenotype, and species adaptation. This study investigates how temperature affects genome-wide DNA methylation patterns, particularly in genes crucial for sex development and whether these modifications can be transmitted across generations. Using the European sea bass —a fish model with both genetic and environmental sex determination— we analyzed DNA methylation at single nucleotide resolution using reduced representation bisulfite sequencing in 64 individuals from five families across two generations (F0 and F1). Parental fish (F0) were exposed to either control (16 °C, C) or elevated (21 °C, T) temperatures from 12 to 60 days post-fertilization. Their offspring (F1) were then subjected to four thermal regimes: control (CC), ancestral exposure via sires (TC), developmental exposure in offspring (CT), and dual exposure (TT). We determined the length of differentially methylated regions (DMRs) using a conservative, reproducible, and species-specific method adapted from plant epigenetics. To disentangle ancestral and developmental temperature effects, DMRs were classified according to their association with F0, F1, or F0 x F1 interaction effects. This allowed us to quantify the relative contribution of each treatment, separately for testes and ovaries in the F1 generation. While the proportion of additive DMRs showing cumulative temperature effects (e.g., 2.1% in testes, 1.4% in ovaries) was relatively rare, a substantial proportion of DMRs (37% in testes, 31.1% in ovaries), exhibited opposing methylation changes with F0 and F1 treatments, indicative of compensatory epigenetic interactions. These interactions were also reflected at the phenotypic level: TT individuals showed body weights comparable to CC, and the sex ratio in TT approached statistical significance when compared to CC (P = 0.051), suggesting a link between epigenetic regulation and phenotypic plasticity under elevated temperatures. Finally, we also investigated the inheritance of epimarks from sires to offspring. While most epimarks remained stable across generations, ~ 5% of all DMRs were both temperature-induced and inherited, offering direct evidence for environmentally responsive multigenerational epigenetic inheritance. This study demonstrates the role of temperature in shaping the epigenome and highlights the potential of epigenetic plasticity and inheritance in species adaptation and conservation amid global warming.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13072-025-00630-5.

This study presents, for the first time, the occurrence and community structure of wild fish inside marine aquaculture cages of gilthead seabream (Sparus aurata), European sea bass (Dicentrarchus labrax), greater amberjack (Seriola dumerili), meagre (Argyrosomus regius), and common dentex (Dentex dentex). Coexistence of farmed and wild fish was observed only in cages of gilthead seabream and European sea bass, with wild fish constituting 0.08% of the total sampled fish biomass. Twelve wild fish species from five families were recorded: Carangidae, Clupeidae, Mugilidae, Moronidae, and Sparidae. Bogue (Boops boops) and jack mackerel (Trachurus sp.) were the most abundant. Multivariate analysis indicated that location significantly influenced the wild fish community composition, while reared species and farming duration, along with their interaction, had no significant effect. Descriptive comparisons suggested potential differences in biometric traits of bogue and jack mackerel between reared species and farming duration. The findings highlight the need for further research on wild fish in cages to better understand the potential health and biosecurity risks they may pose.

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.

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.

BackgroundStructural variants (SVs) are genetic polymorphisms including deletions, insertions, inversions, and duplications, with potential to influence traits through impacts on gene function and expression. SVs have not been widely utilized in genetic analysis, owing to the challenge of their accurate detection and genotyping. Addressing this general issue, and the broader demand to understand their role in commercially important taxa, we report a comprehensive analysis of SVs in the genome of European seabass (Dicentrarchus labrax), the most commercially important fish in the Mediterranean region.ResultsUsing whole genome sequencing from a farmed population (n = 90 samples), 21,428 SVs were identified using a comprehensive detection and genotyping strategy involving manual curation of every variant. This high-confidence SV atlas was annotated to predict impacts on genes and evolutionarily conserved sequences. We explored the overlap between SVs and repeats, identified heterogeneity in SV density across the genome, and tested if the coding genes disrupted by SVs are enriched for specific biological processes or conserved protein domains. SVs impacting evolutionarily conserved genomic regions were enriched in genes with nervous system and developmental functions. Finally, we performed a comparative analysis incorporating 38,408 high-confidence SVs identified independently for three wild populations (n = 80 samples) using identical methods. An analysis of 41,336 SVs merged across the two datasets provides insights into genes and biological functions targeted during aquaculture domestication, with evidence of shifts in allele frequency for SVs located within or near genes controlling behaviour, enriched for forebrain and synaptic functions, and specifically expressed in the brain.ConclusionsThis study sheds light on the global organisation of SVs across the European seabass genome, revealing a potential role in aquaculture domestication. The reported datasets provide a novel, high-quality reference for future genetic investigations of both farmed and wild European seabass.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12915-025-02404-7.

Interactions between micro(nano)plastics and natural organic matter: implications for toxicity mitigation in aquatic species.

Nutritional enhancement of lupin meal (Lupinus albus), through fermentation with Saccharomyces cerevisiae, as plant protein ingredient in aquafeeds for the European sea bass (Dicentrarchus labrax).

Partial dietary fish meal replacement with soybean meal supplemented with papain alters growth, hematological, serum biochemical indices, antioxidant activities and immune response of Sea bass, Dicentrarchus labrax

Impact of dietary protein levels and feeding regimes on growth performance and biochemical profile of European sea bass (Dicentrarchus labrax) reared in a brackish water recirculating aquaculture system

This study aimed to valorize Codium sp. and Osmundea sp. as functional ingredients for European seabass diets. For this purpose, triplicate groups of 25 fish (20.6 g) were fed, during 8 weeks, one of seven diets: the control (CTR), 5% of Codium and Osmundea ground (diets CO and OS, respectively), 5% of Codium and Osmundea ground and autoclaved (diets COA and OSA, respectively), and 0.5% of Codium and Osmundea polysaccharide extracts (diets COP and OSP, respectively). The same diets were used for a digestibility trial. Fish fed the CO diet presented lower growth and an apparent digestibility coefficient (ADC) for dry matter and protein compared to fish fed the CTR and OS diets. Diet COA counteracted these negative effects. No differences were observed in feed intake, feed efficiency, and lipid ADC. Antioxidant enzyme activities and distal intestine histomorphology, an indicator of gut health, were not affected. The expression of interleukin-1β and interleukin-6 increased in fish fed the COP diet. In conclusion, the processing methods counteracted the negative effects of raw Codium, enhancing its value as a dietary ingredient, while its polysaccharides showed immunomodulatory potential that could be valuable during stress or disease periods. These findings support the valorization of these algae for aquafeeds, with Osmundea being safely included at 5% without processing.

Exploring polychaeta meal as a functional ingredient for improving European seabass intestinal health and oxidative status

This study was conducted to determine the validity of three species of frozen fish imported to Iraq. A comparison was made between the status of whole fish and fillets of the same species, and then a comparison was made among the three species of fish: seabream Sparus aurata, seabass Dicentrarchus labrax and tuna Tunnus alalunga, depending on some oxidation tests of frozen fish samples, included determination of free fatty acids (FFA) mg/100 mg fat, total volatile nitrogen (TVN) mg N_2 100g-1 meat, peroxide value (PV) meq Kg-1 meat, and thiobarbituric acid (TBA) mg MDA Kg-1 meat. The results recorded significant differences (P&lt;0.05)) between the case of whole tuna and the fillet of thiobarbituric acid. The results showed that significant differences (P&lt;0.01) were recorded in the total volatile nitrogen value of whole seprim fish and fillets, while tuna fish recorded significant differences (P&lt;0.05)) between the state of whole fish and the fillets. The results recorded significant differences (P&lt;0.01)) in the peroxide value between the state of whole fish and fillets for cyprim fish. The results showed, based on the examinations and comparison with the local and international specifications, that the meat of the fish under study, seabream, seabass and tuna imported to Iraq is considered suitable for human consumption.

Over the past years, with the growing interest in sustainable biomaterials, marine collagen has been emerging as an interesting alternative to bovine collagen. It is more easily absorbed by the body and has higher bioavailability. In this study, collagen was extracted from Dicentrarchus labrax (sea bass) skin, a fishery by-product, thus valorizing waste streams while reducing environmental impact. To overcome the intrinsic weak mechanical of collagen, it was combined with chitosan to produce composite scaffolds for skin tissue engineering. The incorporation of collagen proved crucial for scaffold performance: (i) it promoted the formation of an open-pore architecture, favorable for cell infiltration and proliferation; (ii) it enhanced swelling behavior suitable for exudate absorption and maintenance of a moist wound environment; (iii) by tuning the chitosan/collagen ratio, it enabled us to control the degradation rate; (iv) it conferred antioxidant properties; and (iv) by adjusting collagen/chitosan concentrations, it allowed fine-tuning of mechanical properties, ensuring sufficient strength to resist stresses encountered during wound healing. In vitro assays demonstrated that the scaffolds were non-cytotoxic and effectively supported mouse adipose tissue fibroblasts’ adhesion and proliferation. Finally, all formulations exhibited marked bactericidal activity against the human pathogen Staphylococcus aureus and the methicillin-resistant Staphylococcus aureus, with a Log reduction greater than 3 (a reduction of at least 99.9% in bacterial growth) compared to the control. Collectively, these findings highlight collagen not only as a sustainable resource but also as a functional component that drives the structural, physicochemical, biological, and antimicrobial performance of chitosan/collagen scaffolds for skin tissue engineering.

Viral nervous necrosis, caused by the nervous necrosis virus (NNV), is an important threat to aquaculture, causing great economic losses and a high environmental burden. European sea bass (Dicentrarchus labrax) is highly affected by NNV, and selective breeding programs for disease resistance have been established in order to achieve a sustainable aquaculture and minimize the need for vaccines, drugs and antibiotics. Resistant and susceptible European sea bass were experimentally challenged with NNV and their head kidney transcriptomes were analyzed at three time points, i.e., 3 hpi, 2 dpi and 14 dpi. Numerous differentially expressed genes (DEGs) were identified in the head kidneys of resistant and susceptible infected vs. non-infected sea bass. Gene ontology enrichment, pathway, and protein–protein interaction analyses revealed that the NNV-resistant fish control their response to viral infection more efficiently, utilizing different mechanisms compared to the susceptible fish. Resistant fish displayed higher levels of interferon-related elements, cytokines, antigen presentation, T-cell activity, apoptosis, and programmed cell death combined with a controlled inflammatory response and more active proteasome and lysosome functions. The susceptible fish appeared to have high immune responses at the early infection stages, accompanied by high expressions of inflammatory, complement and coagulation pathways. Insulin metabolism was better regulated in the resistant fish and the control of lipid metabolism was less effective in the susceptible family. The cytoskeleton- and cell adhesion-related pathways were mostly down-regulated in the susceptible fish, and the intracellular transport and motor proteins were utilized more efficiently by the resistant fish. The present study represents a thorough transcriptomic analysis of NNV infection effects on a resistant and a susceptible European sea bass head kidney. The obtained results provide valuable information on the mechanisms that offers pathogen resistance to a host, with many aspects that can be exploited to develop more efficient approaches to fighting viral diseases in aquaculture.