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The blood clam ( Tegillarca granosa ) is being developed into a model bivalve mollusc for assessing and monitoring marine pollution on the offshore seabed. However, the information on the response of blood clam to PAHs, an organic pollutant usually deposited in submarine sediment, remains limited. Herein, we employed multiple biomarkers, including histological changes, oxidative stress, neurotoxicity and global DNA methylation, to investigate the effects of 10 and 100 μg/L Bap exposure on the blood clams under laboratory conditions, as well as the potential mechanisms. Acute Bap exposure can induce significant morphological abnormalities in gills as shown through hematoxylin–eosin (H.E) staining, providing an intuitive understanding on the effects of Bap on the structural organization of the blood clams. Meanwhile, the oxidative stress was significantly elevated as manifested by the increase of antioxidants activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione- s -transferase (GST), lipid peroxidation (LPO) level and 8-hydroxy-2′-deoxyguanosine (8-OHdG) content. The neurotoxicity was also strengthened by Bap toxicity manifested as inhibited acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) activities. In addition, the global DNA methylation level was investigated, and a significant DNA hypomethylation was observed in Bap exposed the blood clam. The correlation analysis showed that the global DNA methylation was negatively correlated with antioxidants (SOD, CAT and POD) activities, but positively correlated choline enzymes (AChE and ChAT) activities. These results collectively suggested that acute Bap exposure can cause damage in gills structures in the blood clam possibly by generating oxidative stress and neurotoxicity, and the global DNA methylation was inhibited to increase the transcriptional expression level of antioxidants genes and consequently elevate antioxidants activities against Bap toxicity. These results are hoped to shed some new light on the study of ecotoxicology effect of PAHs on marine bivalves.

Sturgeons are euryhaline fish species that have developed specific mechanisms of osmotic and ion regulation to adapt to waters of varying salinity. For the aim to elucidate the osmoregulation strategy behind its high salinity tolerance of sturgeons, the transcriptomes of gills in Siberian sturgeon Acipenser baeri under salinity stress (30 ppt) were sequenced using deep-sequencing platform Illumina/HiSeq-2500 and differential expression genes (DEGs) were identified. A total of 167, 501, 278 clean reads were obtained and 280, 238 unigenes were composed of those clean reads with the mean length of 520nt, and the N50 of 630 bp. Unigenes Sequence alignment was implemented via KEGG, KOG, NT, NR, PFAM, Swiss-Prot, and GO databases. 62, 242 unigenes (22.21%) were annoated in at least one database. 11380 significantly differentially expressed unigenes were found, 6969 of which were up-regulated and 4411 were down-regulated by salinity stress. Amongst the top 20 KEGG pathways with the most amount of annotation sequences, some pathways such as glycerophospholipid metabolism, fatty-acid biosynthesis, glycolysis/gluconeogenesis, oxidative phosphorylation have been comprehensively proved to be relevant to osmoregulation. Despite of these, three possible osmoregulation-related signaling pathways as lipid metabolism related pathways, tight junction pathway and thyroid hormone signaling pathway have been widely analyzed in the current study. In all DEGs, some of the typical genes involved in osmoregulation, including calcium-transporting ATPase 4 (ATP2B4), Na + /K + -ATPase alpha subunit (α-NKA), potassium-transporting ATPase alpha chain 1 (ATP4A) and Ras GTPase-activating protein (RasGAP) etc were also identified. RNA-seq results were validated with quantitative real-time PCR (qPCR), the 12 selected genes showed a consistent direction in both DGE library and qPCR analysis, proving that the RNA-seq results are reliable. The present results would be helpful to elucidate the osmoregulation mechanism of aquatic animals adapting to salinity challenge.

The inflammatory cytokine interleukin-17 (IL17) plays an important role in innate immunity by binding to its receptors (IL17Rs) to activate immune defense signals. To date, information on members of the IL17 family is still very limited in molluscan species. Here, a novel member of the IL17 family was identified and characterized from thick shell mussel Mytilus coruscus, and this gene was designated as McIL17-1 by predicting structural domains and phylogenetic analysis. McIL17-1 transcripts existed in all examined tissues with high expression levels in gills, hemocytes and digestive glands. After the stimuli of different pathogen associated molecular patterns (PAMPs) for 72 h, transcriptional expression of McIL17-1 was significantly upregulated, except for poly I:C stimulation. Cytoplasm localization of McIL17-1 was shown in HEK293T cells by fluorescence microscopy. Further, in vivo and in vitro assays were performed to evaluate the potential function of McIL17-1 played in immune response. McIL17-1 was either knocked down or overexpressed in vivo through RNA inference (RNAi) and recombinant protein injection, respectively. With the infection of living Vibrio alginolyticus, a high mortality rate was exhibited in the McIL17-1 overexpressed group compared to the control group, while a lower mortality rate was observed in the McIL17-1 knocked down group than control group. In vitro, the flow cytometric analysis showed that the apoptosis rate of McIL17-1 inhibited hemocytes was significantly lower than that of the control group after lipopolysaccharide stimulation. These results collectively suggested that the newly identified IL17 isoform is involved in the inflammatory response to bacterial infection in M. coruscus.

Macrophage migration inhibitory factor (MIF) is broadly acknowledged as a central pro-inflammatory regulator, owing to its multifaceted functions including immune cell recruitment, initiation and amplification of pro-inflammatory cytokine cascades, enhancement of macrophage viability, facilitation of macrophage polarization toward a pro-inflammatory state, and attenuation of glucocorticoid-mediated immunosuppression. However, functional investigations of MIF in Mytilus coruscus remain limited. In this study, we identified the MIF gene in M. coruscus, and bioinformatic analyses revealed that the gene encodes a 115-amino-acid polypeptide that exhibits close phylogenetic affinity with MIF homologs from other mollusks. McMIF was predominantly expressed in immune-related tissues, with notably high expression levels in the digestive gland. Upon Vibrio alginolyticus infection, both the mRNA and protein levels of McMIF were significantly upregulated, suggesting that McMIF is involved in the antibacterial immune response of M. coruscus. Meanwhile, the m6A modification level of McMIF was markedly reduced following infection, suggesting a potential relationship between m6A modification and the antibacterial immune function of MIF. Furthermore, knockdown of McMIF followed by LPS stimulation led to an increased level of apoptosis in digestive gland cells, suggesting that McMIF is involved in the inhibition of apoptosis induced by immune stimulation. Collectively, these findings provide insights into the immunological characteristics of McMIF in M. coruscus.

Nuclear Factor of Activated T Cells 5 (NFAT5) is a transcription factor that plays a pivotal role in immune regulation. While its functions have been extensively studied in mammalian immune systems, its role in marine invertebrates, particularly in bivalves, remains largely unexplored. This study provides the first characterization of the NFAT5 gene in the thick-shelled mussel (Mytilus coruscus), investigating its evolutionary characteristics and immunological functions. Using direct RNA sequencing, McNFAT5 was comprehensively analyzed, revealing its critical involvement in the innate immune response of M. coruscus to Vibrio alginolyticus challenge. Differential expression patterns of McNFAT5 were observed across various tissues with the highest expression detected in hemolymphs. The knockdown of McNFAT5 using small interfering RNA (siRNA) led to a significant reduction in the activities of superoxide dismutase (SOD), Na+/K+-ATPase, and antioxidant enzymes compared to levels observed post-infection. These findings highlight the central role of McNFAT5 in modulating antioxidant defense mechanisms. In conclusion, McNFAT5 is a key regulatory factor in the innate immune system of M. coruscus, providing valuable insights into the immune adaptive mechanisms and evolutionary mechanisms of bivalve immunity. This study contributes to a deeper understanding of the immune regulatory networks in marine invertebrates.

The aim of this study was to clarify the taxonomic identification of a hemoflagellate and assess the effect of trypanosome infection on Larimichthys crocea . Giemsa staining showed the presence of three morphotypes of trypomastigotes. The trypanosomes had the following morphological characteristics: a slender body with a long flagellum at the front; body size 12.30–30.90 × 1.13–2.33 μm; elongated oval nucleus situated in the median region; kinetoplast small, oval, located at the posterior end. The parasite had significant morphological differences from Trypanosoma epinepheli Su, Feng, Jiang, Guo, Liu & Xu, 2014 and Trypanosoma carassii (Mitrofanov) Doflein, 1901. The 18S rDNA sequences of the trypanosome from L. crocea had the highest homology (98.4%) with T. carassii . Phylogenetic analysis indicated that the parasite clustered with freshwater fish trypanosomes. Based on the differences in morphological characteristics and molecular data, it is considered a new species, Trypanosoma larimichthysi n. sp. Trypanosome infection had no effect on the growth of L. crocea , but significantly increased the concentration of blood urea nitrogen (BUN), and induced pathological changes in the gills, liver, spleen and kidney. The pro-inflammatory immune genes, including TNF-α , IFN-γ , IL-1β , CXCL8 and iNOS , were significantly upregulated in the L. crocea infected with trypanosomes. These results suggest that the trypanosome has negative impacts on host health. Le but de cette étude était de clarifier l’identification taxonomique d’un hémoflagellé et d’évaluer l’effet de l’infection trypanosomienne sur Larimichthys crocea . La coloration au Giemsa a montré la présence de trois morphotypes de trypomastigotes. Les trypanosomes avaient les caractéristiques morphologiques suivantes : un corps élancé avec long flagelle à l’avant; taille du corps 12,30–30,90 × 1,13–2,33 μm; noyau ovale allongé situé dans la région médiane; kinétoplaste petit, ovale, situé à l’extrémité postérieure. Le parasite présentait des différences morphologiques significatives par rapport à Trypanosoma epinepheli Su, Feng, Jiang, Guo, Liu & Xu, 2014 et Trypanosoma carassii (Mitrofanov) Doflein, 1901. Les séquences d’ADNr 18S du trypanosome de L. crocea présentaient la plus forte homologie (98,4 %) avec T. carassii . L’analyse phylogénétique a indiqué que le parasite se regroupait avec les trypanosomes de poissons d’eau douce. Sur la base des différences dans les caractéristiques morphologiques et les données moléculaires, il est considéré comme une nouvelle espèce, Trypanosoma larimichthysi n. sp. L’infection par les trypanosomes n’a eu aucun effet sur la croissance de L. crocea , mais a augmenté de manière significative la concentration d’azote uréique du sang (BUN) et a induit des modifications pathologiques des branchies, du foie, de la rate et des reins. Les gènes immunitaires pro-inflammatoires, dont TNF-α , IFN-γ , IL-1β , CXCL8 et iNOS , ont été significativement régulés à la hausse chez les L. crocea infectés par les trypanosomes. Ces résultats suggèrent que le trypanosome a des impacts négatifs sur la santé de l’hôte.

Marine fisheries scientific and technological innovation level (MFSTIL) drives the modernization and sustainability of China’s fisheries. Based on the panel data of 11 coastal provinces and cities in China from 2011 to 2022, the article used the entropy weight-TOPSIS method, spatial econometric model (Standard Deviation Ellipse), Dagum Gini coefficient, Markov modified grey prediction model and other methods to analyze the spatiotemporal differentiation of China’s MFSTIL and its future development trend. The results show that: (1) China’s MFSTIL was generally good and grew steadily year by year from 2011 to 2022, but regional development was uneven; (2) The temporal evolution of MFSTIL has a sequence of “slow rise-rapid rise-steady rise”, and the differentials between regions also fluctuate upward; (3) The spatial pattern of MFSTIL is uneven in distribution, and there are “lagging areas” in the three major marine economic zones; in terms of evolution, it has the dynamic equilibrium characteristics of “northeast-southwest”, and the center of gravity of the standard deviation ellipse moves first to the northeast and then to the southwest; (4) The overall spatial variation in MFSTIL has increased year by year in recent years, with hyper-variance density contributing most significantly to regional differences; (5) The MFSTIL will maintain the growth trend of the previous 12 years in 2023-2030, and the ranking of provinces will change slightly. The gap between the northern and eastern regions will narrow, while their disparity with the southern region will widen, the absolute gap between regions cannot be ignored. In this regard, the article proposed following suggestions: (1) Implement targeted support strategies through special funds and the construction of industry-academia-research integration platforms to identify and empower regions lagging behind in innovation, thereby stimulating local scientific research and innovation capabilities; (2) Optimize the spatial layout of the three major marine economic zones, build integrated industrial chains, and achieve complementary regional development; (3) Establish a dynamic monitoring and early warning system based on big data and the Internet of Things to achieve real-time monitoring of resources, the environment, markets, and industries, thereby promoting sustainable and balanced development.

Understanding how aquatic invertebrates respond and adapt to rapid environmental change remains a key challenge in marine ecology. In recent years, environmental epigenetics has emerged as an important interdisciplinary approach, with a noticeable increase in related studies since 2020. Based on publications from 2014 to 2025, this study uses CiteSpace and VOSviewer to carry out a bibliometric analysis, aiming to outline the knowledge structure, collaboration patterns, and research development in this field. The global research network demonstrates methodological and resource complementarity, with multi-omics sequencing institutions partnering with regional marine stations that contribute taxonomically diverse aquatic invertebrate samples and localized environmental exposure data. China contributes the largest share of publications, while the overall connectivity of the network largely depends on collaborations led by the United States. At the same time, several limitations remain evident. Current studies rely heavily on DNA methylation, focus mainly on a limited number of taxa (especially aquaculture-related mollusks) and often overlook the complexity of natural environmental conditions in experimental design. In terms of research themes, the field appears to be shifting from descriptive studies linking environmental factors and phenotypic responses toward work that explores mechanisms of transgenerational adaptation. To move forward, future research should expand the use of multi-omics approaches to a wider range of non-model organisms, develop longer-term experiments under multiple stressors, and place greater emphasis on in situ validation. These efforts will be important for improving our ability to predict the resilience of benthic organisms under ongoing climate change.

Ocean warming can cause injury and death in mussels and is believed to be one of the main reasons for extensive die-offs of mussel populations worldwide. However, the biological processes by which mussels respond to heat stress are still unclear. In this study, we conducted an analysis of enzyme activity and TMT-labelled based proteomic in the digestive gland tissue of Mytilus coruscus after exposure to high temperatures. Our results showed that the activities of superoxide dismutase, acid phosphatase, lactate dehydrogenase, and cellular content of lysozyme were significantly changed in response to heat stress. Furthermore, many differentially expressed proteins involved in nutrient digestion and absorption, p53, MAPK, apoptosis, and energy metabolism were activated post-heat stress. These results suggest that M. coruscus can respond to heat stress through the antioxidant system, the immune system, and anaerobic respiration. Additionally, M. coruscus may use fat, leucine, and isoleucine to meet energy requirements under high temperature stress via the TCA cycle pathway. These findings provide a useful reference for further exploration of the response mechanism to heat stress in marine mollusks.

In the cultivation of Mytilus unguiculatus, the broodstock are shade-dried to stimulate sperm and egg production. To identify the functional genes affecting gonad development in M. unguiculatus, the transcriptome of gonads in mussels stimulated by shade-drying and those not stimulated were compared. Differential gene expression analysis revealed that there were 22 differentially expressed genes (DEGs) in the testis and 70 DEGs in the ovary among the experimental groups. KEGG enrichment analysis identified a total of 11 pathways that might be related to environmental stimuli affecting gonadal development. Nicotinic acetylcholine receptors (AChRs), the cholecystokinin A receptor (CCKAR), hypocretin (orexin) receptor 2 (HCRTR2), and gamma-aminobutyric acid type B receptor (GABBR) were highly expressed in the neuroactive ligand-receptor interaction pathway, indicating that these genes might be involved in the transduction of environmental information that stimulates gonadal development. Meanwhile, nuclear receptor co-repressor 2 (NCoR2) was highly expressed in the notch signaling pathway, indicating that NCoR2 might be involved in the regulation of gonad development. To validate the transcriptome data, we selected five DEGs in the KEGG signaling pathway, including AChRs, CCKAR, HCRTR2, GABAB, and NCoR2, for real-time quantitative PCR (RT-qPCR), which produced results consistent with the RNA-Seq data. The transcriptome analysis and gene pathway identification in this study have enhanced our comprehension of the reproductive mechanisms in M. unguiculatus.