Sebastiscus Marmoratus Research Articles

Species Composition of Fish Larvae and Juveniles in the Nanji Islands, China

To describe the species composition of fish larvae and juveniles in the Nanji Islands, monthly collection was conducted at 12 stations around the Nanji Islands from March 2023 to February 2024 by using horizontal tow at the surface layer. The fish larvae and juveniles were collected by a larva net (1.3 m mouth diameter, 0.5 mm mesh aperture). A total of 6446 fish larvae and juveniles were collected, belonging to 59 species and 54 genera in 11 families. Most of them were preflexion larvae (93.31%). Gobiidae, with eight species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Sebastiscus marmoratus (Cuvier, 1829), accounting for 84.52% of the total number of samples collected. The common species were Stolephorus commersonii Lacepède, 1803; Omobranchus elegans (Steindachner, 1876); Nibea albiflora (Richardson, 1846); Parablennius yatabei (Jordan & Snyder, 1900); Lateolabrax maculatus (McClelland, 1844); and Odontamblyopus lacepediiand (Temminck & Schlegel, 1845). Other species were all rare species. The highest species number was in September (18 species), and the highest density was in December. Only one fish larva was collected in April. Pielou’s evenness index was highest in November, while Margalef’s richness index and Shannon–Wiener diversity were highest in September. The result of cluster analysis showed that the 11 months (except April) could be divided into four groups. The species number, density, and three diversity indexes showed no significant correlation with temperature and salinity.

Use of Environmental DNA to Evaluate the Spatial Distribution of False Kelpfish (Sebastiscus marmoratus) in Nearshore Areas of Gouqi Island

This study aims to explore the spatial distribution of false kelpfish (Sebastiscus marmoratus) in the mussel farming area, artificial reef areas of Gouqi Island (Shengsi, China), and natural areas using eDNA detection methods. Surface and bottom water samples were collected at 12 stations in November 2022 and April 2023, totaling 52 samples. We used species-specific primers and probes for quantitative PCR (qPCR) detection of Sebastiscus marmoratus eDNA. The eDNA concentrations differed seasonally (p < 0.05) and did not differ (p > 0.05) among the three sampling areas and two water layers. The greatest eDNA concentrations occurred in the surface layer during the spring. Higher concentrations of Sebastiscus marmoratus eDNA were also found in the mussel aquaculture area. Temperature exhibited a significant positive correlation with Sebastiscus marmoratus eDNA concentration (p < 0.05). Additionally, we developed linear equations predicting the relationship between environmental factors and environmental factors, providing a reference for future fishery resource surveys.

Disparities in Body Color Adaptability and Ambient Light Color Preference between Wild and Hatchery-Reared Marbled Rockfish (Sebastiscus marmoratus).

Hatchery rearing significantly influences the phenotypic development of fish, with potential adverse effects for the post-release performance of hatchery-reared individuals in natural environments, especially when targeted for stock enhancement. To assess the suitability of releasing hatchery-reared fish, a comprehensive understanding of the phenotypic effects of captive rearing, through comparisons with their wild conspecifics, is essential. In this study, we investigated the divergence in body coloration between wild and hatchery-reared marbled rockfish Sebastiscus marmoratus. We examined the selection preferences for different light colors and assessed the impact of different ambient light colors on the morphological color-changing ability of juvenile marbled rockfish. Our findings revealed significant differences in body color between wild and hatchery-reared marbled rockfish. The hue and saturation values of wild marbled rockfish were significantly higher than those of their hatchery-reared counterparts, indicative of deeper and more vibrant body coloration in the wild population. Following a ten-day rearing period under various light color environments, the color of wild marbled rockfish remained relatively unchanged. In contrast, hatchery-reared marbled rockfish tended to change their color, albeit not reaching wild-like coloration. Light color preference tests demonstrated that wild juvenile marbled rockfish exhibited a preference for a red-light environment, while hatchery-reared individuals showed a similar but weaker response. Both wild and hatchery-reared marbled rockfish displayed notable negative phototaxis in the presence of yellow and blue ambient light. These results highlight the impact of hatchery rearing conditions on the body color and morphological color-changing ability, and provide insight into light color selection preferences of marbled rockfish. To mitigate the divergence in phenotypic development and produce more wild-like fish for stocking purposes, modifications to the hatchery environment, such as the regulation of ambient light color, should be considered.

Does the Artificial Enhancement and Release Activity Affect the Genetic Diversity of Marbled Rockfish Sebastiscus marmoratus in Zhoushan Waters?

Artificial enhancement and release activity is an important method in the restoration of fishery resources. In order to understand the possible genetic effect of hatchery-released populations on wild populations during the artificial enhancement and release activities of Sebastiscus marmoratus in Zhoushan waters, we utilized mitochondrial DNA control region sequences to examine the genetic diversity in four S. marmoratus populations, including one farmed population, one released population and two wild populations. A total of 68 haplotypes from 123 individuals were detected, including 3 shared haplotypes. Haplotype diversity ranged from 0.944 to 0.980, with a mean of 0.966. The nucleotide diversity ranged from 0.020 to 0.025, with a mean of 0.022. Analysis of Molecular Variance (AMOVA) indicated that the primary genetic variation occurs within populations and the index of genetic differentiation between populations (FST) among the four populations showed no differentiation. The results indicate that the current artificial enhancement and release has not impacted the S. marmoratus population in Zhoushan waters. Continued long-term monitoring is essential to protect the high-quality germplasm resources of S. marmoratus.

Otolith morphology as a tool for stock discrimination of three rockfish species in the East Sea of Korea

The shape and structure of otoliths play a vital role in studying fish populations because otolith shape indices are often applied to discriminate fish species. This study focused on examining inter- and intra-specific variations in otolith shape and size among three species of rockfish (Sebastes inermis, Sebastiscus marmoratus, and Sebastes zonatus) collected from the Dokdo and Ulleungdo regions of the East Sea in Korea. A total of 35 S. inermis specimens, 19 S. marmoratus specimens, and 59 S. zonatus specimens were collected between April 2021 and August 2022. The otolith shape was visualized using wavelet coefficients in the shapeR package. Otolith size indices, such as length, width, perimeter, and area, and shape indices, including form factor, aspect ratio, ellipticity, circularity, roundness, rectangularity, and squareness, were calculated for each species. Otolith size and shape indices significantly differed among the three rockfish species (p< 0.05). Compared with the other two species, S. marmoratus possessed more elongated otoliths, whereas S. zonatus had the largest otolith area, perimeter, and length. Average shape analysis based on wavelet coefficients revealed significant differences in otolith shape, particularly on the rostrum and posterior sides. A canonical analysis of principal components (CAP) confirmed the complete separation of otolith shapes among the three rockfish species, with 92.5% of the variation explained by the first axis (CAP1). The findings of this study enhance our understanding of the fish species in the Korean East Sea.

Hsp70 Gene Family in Sebastiscus marmoratus: The Genome-Wide Identification and Transcriptome Analysis under Thermal Stress.

Heat shock protein 70 kDa (Hsp70) is a highly conserved heat stress protein that is important in biotic processes and responses to abiotic stress. Hsp70 genes may be important in Sebastiscus marmoratus, for it is a kind of nearshore reef fish, and habitat temperature change is more drastic during development. However, genome-wide identification and expression analysis in the Hsp70 gene family of S. marmoratus are still lacking. Here, a total of 15 Hsp70 genes in the genome of S. marmoratus are identified, and their expression patterns were investigated using transcriptomic data from thermal stress experiments. The expansion and gene duplication events of Hsp70 genes from the Hspa4, Hspa8, and Hspa12a subfamilies in S. marmoratus are revealed by phylogenetic analysis. qRT-PCR expression patterns demonstrated that seven Hsp70 genes were significantly up-regulated and none were significantly down-regulated after heat treatment. Only the hsp70 gene was significantly up-regulated after cold treatment. The selection test further showed a purifying selection on the duplicated gene pairs, suggesting that these genes underwent subfunctionalization. Our results add novel insight to aquaculture and biological research on S. marmoratus, providing important information on how Hsp70 genes are regulated in Scorpaeniformes under thermal stress.

Trophic niche and potential carbon source of three reef-associated fishes of Zhongjieshan Islands.

To clarify the trophic relationship of important rock fishes, we analyzed trophic niche of three typical rockfish species (Oplegnathus fasciatus, Sebastiscus marmoratus and Conger myriaster) in the Zhongjieshan Islands in summer 2020, based on the carbon and nitrogen stable isotope techniques. We calculated the contributions of major carbon sources [macroalgae, phytoplankton, suspended particulate organic matter (POM) and substrate organic matter (SOM)]. The results showed that: 1) the δ13C values of the three species ranged from -21.44‰ to -15.21‰, with an average value of (-16.85±1.12)‰, while the δ15N values ranged from 8.32‰ to 10.96‰, with an average value of (9.69±0.66)‰. There were significant differences in carbon and nitrogen stable isotopes among the three species. 2) There was small niche overlap between O. fasciatus and S. marmoratus, indicating that the interspecific competition was not intense. There was no overlap between C. myriaster and the first two, indicating feeding differentiation. 3) The total ecotone area, corrected core ecotone area, and food source diversity of C. myriaster were the highest, indicating that it had a more generalized diet and richer food sources. 4) With Mytilus coruscus as a baseline organism, the trophic level of C. myriaster was the highest (3.38), followed by S. marmoratus (3.09), and the trophic level of O. fasciatus was the smallest (3.00). 5) Results of the stable isotope mixture model (SIAR) showed that POM was the main carbon source of the three species, contributing 57.4%, 57.9%, and 92.0% of the total, respectively. In addition, the contribution rate of SOM was also high for O. fasciatus and S. marmoratus, which was 21.5% and 33.9%, respectively. This study could provide basic information and reference for understanding trophic structure and marine food web in Zhongjiashan Islands.

Transcriptome Analysis of Marbled Rockfish Sebastiscus marmoratus under Salinity Stress.

The marbled rockfish, Sebastiscus marmoratus, belongs to the euryhaline fish and is an oviparous scleractinian fish. There are few studies on the adaptation mechanism, functional genes, and related pathways of S. marmoratus and salinity. The results showed that a total of 72.1 GB of clean reads were obtained and all clean reads annotated a total of 25,278 Unigenes, of which 2,160 were novel genes. Compared to 20‱, 479 and 520 differential genes were obtained for 35‱ and 10‱, respectively. Gene ontology (GO) enrichment analysis revealed significant enrichment in protein binding, ion binding, ATP binding, and catalytic activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that differentially expressed genes significantly expressed under salinity stress were mainly involved in the pathways of the cytochrome P450 metabolism of xenobiotics, tryptophan metabolism, cellular senescence, and calcium signaling pathways. Among them, pik3r6b, cPLA2γ-like, and WSB1 were differentially expressed in all three groups, and they were associated with apoptosis, inflammation, DNA damage, immune regulation, and other physiological processes. Six differentially expressed genes were randomly selected for qRT-PCR validation, and the results showed that the transcriptomic data were of high confidence.

Applying a fish expert system for ranking the biological effects of polycyclic aromatic hydrocarbons on the rockfish Sebastiscus marmoratus in the Maowei Sea, China

Applying a fish expert system for ranking the biological effects of polycyclic aromatic hydrocarbons on the rockfish Sebastiscus marmoratus in the Maowei Sea, China

Differences in Light Attenuation Patterns of Sargassum horneri Beds and Their Influences on Sebastiscus marmoratus Juveniles: A Case Study of Gouqi Island, Ma’an Archipelago, China

Sargassum beds ensure sustainable environmental, social, and economic benefits in the coastal areas around the world. They can provide shelter ground to different species of fish juveniles. To investigate these, we conducted field surveys in a peaking growth period of Sargassum horneri from May to June 2010 to evaluate them on Gouqi Island, Ma’an archipelago, China. The study indicated that the light attenuation rate inside the S. horneri beds was higher than that in the surrounding areas. The light attenuation rate was highest in Ganxie, the second highest in Huangshidong, and the lowest in Houtouwan. We found that the average length of Sebastiscus marmoratus corresponded to the average height of S. horneri. This study improves our understanding of the function of sheltering grounds provided by Sargassum beds. Additionally, this study is relevant to the development of the regulations and directives to ensure the sustainable exploitations and protection of wild seaweeds and the accompanying organisms resources.

Genome-Wide Identification, Characterization and Expression Analysis of Toll-like Receptors in Marbled Rockfish (Sebastiscus marmoratus).

Toll-like receptor (TLR) is a cluster of type I transmembrane proteins that plays a role in innate immunity. Based on the marbled rockfish (Sebastiscus marmoratus) genome database, this study used bioinformatics methods to identify and analyze its TLR gene family members. The results showed that there were 11 TLR gene family members in Sebastiscus marmoratus (SmaTLR), which could be divided into five different subfamilies. The number of amino acids encoded by the Smatlr genes ranged from 637 to 1206. The physicochemical properties of the encoded proteins of different members were also computed. The results of protein structure prediction, phylogenetic relation, and motif analysis showed that the structure and function of the SmaTLRs were relatively conserved. Quantitative Real-Time PCR (qRT-PCR) analysis revealed the expression patterns of SmaTLRs in the gill, liver, spleen, head kidney, kidney, and intestine. SmaTLRs were widely detected in the tested tissues, and they tended to be expressed higher in immune-related tissues. After polyriboinosinic polyribocytidylic acid (poly(I:C)) challenge, SmaTLR14, SmaTLR3, SmaTLR5S, SmaTLR7, and SmaTLR22 were significantly upregulated in the spleen or liver. The results of this study will help to understand the status of TLR gene family members of marbled rockfish and provide a basis for further study of the functional analysis of this gene family.

Differences in External Morphology, Body Composition and Swimming Performance Between Hatchery- and Wild-Origin Marbled Rockfish (Sebastiscus marmoratus)

Stock enhancement based on hatchery-reared fish has become one of the most common forms of management practices in marine fisheries resource restoration. However, unnatural rearing environments may cause hatchery-reared fish to diverge phenotypically from wild conspecifics, with negative consequences for post-release performance in the natural environments. To better evaluate the suitability of releasing hatchery-reared fish, it is necessary to understand the phenotypic effects of captive rearing, through comparisons with wild conspecifics. In this study, we compared body morphology, swimming performance, and biochemical body composition between hatchery-reared and wild marbled rockfish (Sebastiscus marmoratus) from the same general gene pool. The results show that the overall body profile differed significantly between the groups, with hatchery-reared individuals having a deeper body (in particular in the head and trunk regions), narrower caudal peduncles, and higher condition factor, as compared to wild conspecifics. Hatchery-reared marbled rockfish also had relatively shorter fins, for a given size. In terms of swimming performance, the hatchery-reared marbled rockfish performed worse than the wild, with slower burst swimming speeds and poorer endurance. Wild rockfish had higher body protein content but lower lipid levels compared to the hatchery-reared individuals. These results suggest that hatchery rearing conditions have a great impact on the phenotypic development, with possibly high effects on their post-release performance of the hatchery-reared marbled rockfish. Modifications for the hatchery environment and operation should be investigated with an aim to minimize the divergence in phenotypic development for production of more wild-like fish for stocking.

A Comparison of Fish Diversity in Rocky Reef Habitats by Multi-Mesh Gillnets and Environmental DNA Metabarcoding

This study was undertaken in order to explore the practical effectiveness of the environmental DNA (eDNA) metabarcoding approach in evaluating fish composition and diversity in a high heterogeneous rocky reef habitat. We assessed the fish composition and diversity characteristics of the rocky reef habitat at Dachen Islands, Taizhou and the Zhejiang Province in China in November 2020 by comparing two methods: multi-mesh gillnets and eDNA. A comparative analysis was carried out on the fish composition and diversity characteristics gained under the two methods by using taxonomy, ecotypes and diversity indices. The results showed that there were 28 species of fish collected through gillnets, distributed under 24 genera, 19 families, 6 orders and one class. Among them, 4, 18, and 6 species of near-surface, near groundfish and groundfish were found, respectively, with Thryssa mystax, Johnius belangerii, and Sebastiscus marmoratus being the dominant species in each water layer. A total of 81 species of fish detected by eDNA metabarcoding belonging to 67 genera, 46 families, 15 orders and 2 classes. The near-surface, near groundfish and groundfish species were 17, 42, and 22, with Thryssa vitrirostris, Benthosema pterotum, Harpadon nehereus, and Dasyatis akajei being the dominant species in each water layer. Twenty species (71.4%) and 41 species (50.6%) of reef fish were counted by gillnets and eDNA, respectively. The results showed that multi-mesh gillnets can accurately obtain information on fish composition in rocky reef habitats, but with some selectivity. The eDNA technology can detect species not collected by gillnets, but the number of species detected in areas with fast water velocity is significantly less than other eDNA stations where the water velocity is slow. In summary, the combination of traditional nets and eDNA will provide more information on taxonomic diversity and population biomass, transforming natural resource management and ecological studies of fish communities on a larger spatial and temporal scale.

Antimicrobial and immunoregulatory activities of the derived peptide of a natural killer lysin from black rockfish (Sebastes schlegelii)

Natural killer lysin (NK-lysin) is a small molecule antimicrobial peptide secreted by natural killer cells and T lymphocytes. In this study, we characterized a cDNA sequence encoding an NK-lysin homologue (SsNKL1) from black rockfish, Sebastes schlegelii. The open reading frame (ORF) of SsNKL1 encodes a putative protein of 149 amino acids and shares 44%–87% overall sequence identities with other teleost NK-lysins. SsNKL1 possesses conserved NK-lysin family features, including a signal sequence and a surfactant-associated protein B (SapB) domain, sequence analysis revealed that SsNKL1 is most closely related to false kelpfish (Sebastiscus marmoratus) NK-lysin (with 87% sequence identity). SsNKL1 transcripts were detected in all the tested tissues, with the highest level in the kidney, followed by the spleen and gills. Upon Listonella anguillarum infection, the mRNA expression of SsNKL1 in the black rockfish was significantly up-regulated in the liver and kidney. The derived peptide SsNKLP27 from SsNKL1 was synthesized, and its biological function was studied. SsNKLP27 showed direct antibacterial activity against Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Bacillus subtilis, L. anguillarum, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus. SsNKLP27 treatment facilitated the bactericidal process of erythromycin by enhancing the permeability of the outer membrane. In the process of interaction with the target bacterial cells, SsNKLP27 changed the permeability and retained the morphological integrity of the cell membrane, then penetrated into the cytoplasm, and induced the degradation of genomic DNA and total RNA. In vivo studies showed that administration of SsNKLP27 before bacterial and viral infection significantly reduced the transmission and replication of pathogens in tissues. In vitro analysis showed that SsNKLP27 could enhance the respiratory burst ability and regulate the expression of some immune-related genes of macrophages. In summary, these results provided new insights into the function of NK-lysins in teleost fish and support that SsNKLP27 is a new broad-spectrum antimicrobial peptide that has a potential application prospect in aquaculture against pathogenic infection.

Comparative transcriptomic analysis of the liver and spleen in marbled rockfish (Sebastiscus marmoratus) challenged with polyriboinosinic polyribocytidylic acid (poly(I:C))

Marbled rockfish (Sebastiscus marmoratus) is a common coastal fish in China with considerable market value. The artificial culture of this species has not been widely popularized, and there have been few research on its vaccine or immune adjuvant. In this study, we performed transcriptome analysis of marbled rockfish spleen and liver tissue samples at 12 and 48 h after the polyinosinic-polycytidylic acid (poly(I:C)) challenge. Compared with the control group, 1067 and 598 differentially expressed genes (DEGs) were identified in the spleen and liver, respectively. GO, and KEGG enrichment analyses of DEGs revealed that some immune-related biological processes and pathways were significantly changed after poly(I:C) treatment, including primary immunodeficiency, the NF-kappa B signaling pathway, the Jak-STAT signaling pathway, and the PPAR signaling pathway. In conclusion, the findings of this research provide new insights into the immune response of marbled rockfish against poly(I:C) at the transcriptome level, and enrich the theoretical basis for the development of its immune adjuvant.

PAH residue and consumption risk assessment in four commonly consumed wild marine fishes from Zhoushan Archipelago, East China Sea

The concentration, constitution, distribution, possible sources, and associated consumption risks of polycyclic aromatic hydrocarbons (PAHs) in four marine fishes in the Zhoushan Archipelago were investigated. The concentrations of PAHs in the edible muscle of these four fishes ranged from 34.7 to 108 ng/g wet weight. Four-ring and six-ring PAH congeners constitute the most and least percentages of the total PAHs, respectively. The highest PAH concentrations were found in Mugil cephalus, followed by Sebastiscus marmoratus, Lateolabrax maculatus, and Collichthys lucidus. The highest PAH concentrations were found at the sampling island Liuheng, followed by Gouqi, Qushan, Dongji, and Zhujiajian. PAH concentrations in wet weight were remarkably different among these four fish species but not among different locations. High-molecular-weight congeners predominated the PAH composition pattern in most of the samples. Results showed that the consumption of M. cephalus might have potential carcinogenic risk. This study provided baseline data on PAH concentrations in seafood and consequent human consumption risk.

Potential effects of underwater noise from wind turbines on the marbled rockfish (Sebasticus marmoratus)

Environmental assessments of underwater noise on marine species must be based on species-specific hearing abilities. This study was to assess the potential impact of underwater noise from the East China Sea Bridge wind farm on the acoustic communication of the marbled rockfish. Here, the 1/3 octave frequency band of underwater noise was 125 Hz with the level range of 78–96 dB re 1 μPa, recorded at distances between 15-20m from the foundation at wind speed of 3–5 m/s. Auditory evoked potential (AEP) and passive acoustic techniques were used to determine the hearing abilities and sound production of the fish. The resultes showed the lowest auditory threshold of Sebastiscus marmoratus was 70 dB at 150 Hz matching the disturbance sound ranging 140–180 Hz, which indicating the acoustic communication used in this species. However, the frequency and level of turbine underwater noise overlapped the auditory sensitivity and vocalization of Sebastiscus marmoratus. The wind turbine noise could be detected by fish and may have a masking effect on their acoustic communication. This result can be applied for further to the assessent of fish species released into offshore wind farm marine ranch.

Quantitative assessment of fish assemblages on artificial reefs using acoustic and conventional netting methods, in Xiangshan Bay, Zhejiang Province, China

Artificial reefs are often deployed by many countries for the purpose of enhancing fishing after a period of several years. The objective of this study was to analyze the effect of a pilot artificial reef system deployment in enhancing the demersal fish assemblages, investigated using both acoustic methods and bottom trammel nets, during four years between 2011 and 2017, in Xiangshan Bay, Zhejiang Province, China. Comparisons of community indices, including fish biomass, species richness and species diversity, indicated relatively consistent trends between the control sites and the artificial reefs following their deployment in 2012. Fish density, represented by the value of the nautical area scattering coefficient, and fish biomass were significantly higher on the artificial reefs than at the control sites in 2015 and 2017, and species richness and diversity were significantly greater at the reefs from 2013 to 2017. Blackhead seabream (Acanthopagrus schlegelii) and false kelpfish (Sebastiscus marmoratus) were the dominant fishes on the artificial reefs, and the average body lengths of these two species were significantly greater 40 and 64 months after deployment. Thus, construction of the artificial reefs appears to have achieved their primary purpose as fish-attraction devices, thereby contributing to ecological restoration in Xiangshan Bay.

A new and a known species of Taeniacanthus Sumpf, 1871 (Copepoda, Cyclopoida, Taeniacanthidae) parasitic on Japanese fishes

Abstract Taeniacanthus aulacocephali sp. nov. recovered from Aulacocephalus temminckii Bleeker, 1855 (Serranidae) is described and T. sebastichthydis Yamaguti, 1939 collected from Sebastiscus marmoratus (Cuvier, 1829) and Sebastes inermis Cuvier, 1829 (Sebastidae) is redescribed. The male, copepodid V male, both sexes of copepodid IV, and copepodid II of the latter species are herein described for the first time.

Developing and applying a classification system for ranking the biological effects of endocrine disrupting chemicals on male rockfish Sebastiscus marmoratus in the Maowei Sea, China

Endocrine disrupting compounds (EDCs) in marine environments has become a major environmental concern. Nonetheless, the biological effects of EDCs on organisms in coastal environments remain poorly characterized. In this study, biomonitoring of EDCs in male fish Sebastiscus marmoratus was carried out in the Maowei Sea, China. The results showed that the concentration of 4-nonylphenol (4-NP) was below the detection limit, the concentrations of 4-tert-octylphenol (4-t-OP) and bisphenol A (BPA) in seawater were moderate compared with those in other global regions, and the possible sources are the municipal wastewater discharge. Nested ANOVA analyses suggest significant differences of the brain aromatase activities and plasma vitellogenin (VTG) expression between the port area and the oyster farming area. A new fish expert system (FES) was developed for evaluating the biological effects of EDCs on fish. Our findings show that the FES is a potential tool to evaluate the biological effects of marine pollutants.