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  • Evaluation of low-salt tolerance of razor clams (Sinonovacula constricta) from different families and their physiological responses
    ZHAN Tianyu, ZHANG Na, YE Kai, BAI Zengqi, KANG Pengtian, NIU Donghong
    Journal of Dalian Fisheries University. 2025, 40(5): 780-788. https://doi.org/10.16535/j.cnki.dlhyxb.2025-068
    Abstract (3478) PDF (787) HTML (4)   Knowledge map   Save
    To evaluate low salt tolerance of different family lines of razor clam (Sinonovacula constricta), we exposed specimens from six razor clam family lines (8, 13, 14, 23, 24, and 28) to low salt (2 salinity) or control (20 salinity) conditions to carry out low salt stress experiments. Tissue damage, apoptosis, Na+/K+-ATPase (NKA) activity, and antioxidant enzyme activity were measured and compared among the specimens from the different families. The results showed that the mortality rates of razor clams from F8, F13, and F14 were >80% but the survival curves of all families were similar. The Pearson correlation between razor clam survival and shell width was highly significant (P<0.01), and the Spearman correlation between shell width and body weight was significant (P<0.05). Hematoxylin and eosin (HE) staining showed that clams from F8, F13, and F14 had normal gill tissue structure by 48 h, some gill filaments were swollen at 72 h, gill spacing was reduced, gill volume was enlarged, and the area of broken region was increased at 96 h. Clams from the F23 group had slight edema of localized gill filaments at 72 h, and their damage extent were not worse than those from F8, F13, and F14 by 96 h. F24 and F28 clams had intact gill filament structure at 96 h of the stress cycle. The level of apoptosis was observed by Hoechst 33342 staining, showing that the nuclei of F8, F13, and F14 cells displayed dense bright blue patches, with aggregates of apoptotic vesicles and more apoptosis. In clams from the F23 group, the proportion of apoptotic cells was reduced; and the proportions of apoptotic cells were lower in F24 and F28 clams, with occasional sporadic apoptotic vesicles. The activity of NKA of clams from all family lines decreased continuously during 12 h of low salt stress, and the enzyme activities of clams from the F23, F24, and F28 increased significantly by 24 h but then decreased.The NKA activity levels of F8 and F13 clams decreased continuously, and the value of F8 was always lower than that of F13.The antioxidant enzyme activity assay showed that the catalase activity of two lines (F13 and F14) was always lower than that of the other lines. The superoxide dismutase activity of clams in all families increased and then decreased, with the maximum value at 24 h. The malondialdehyde content of clams in the F8, F13, and F14 groups was higher than that of clams in the F23, F24, and F28 groups at the end of the low salt stress period. In conclusion, the six razor clam families had different tolerances to low salt conditions, and the F23, F24, and F28 clams were the most tolerant. The study results provide a reference for further breeding new low salt-tolerant razor clam lines.
  • The current development status and future prospects of smart fisheries technology:a review
    LIU Huang, LIU Shijing
    Journal of Dalian Fisheries University. 2025, 40(4): 541-551. https://doi.org/10.16535/j.cnki.dlhyxb.2025-183
    Abstract (3377) PDF (1711) HTML (4)   Knowledge map   Save
    Smart fisheries are an important means of improving fishery production efficiency and promoting the modernization and transformation of the fishery industry. By deeply integrating advanced technologies such as multisensing, the Internet of Things (IoT), big data, and artificial intelligence, smart fisheries have made significant progress in key areas such as breeding, aquaculture, fishing, and processing. However, the new trends in the high quality development of modern fisheries pose higher demands on the development of smart fisheries. This paper systematically reviews the major research progress in smart fisheries technologies from three dimensions: information sensing, transmission, and analysis and decision-making. It also outlines the technology development trends and summarizes the current applications of intelligent technologies in breeding, aquaculture, resources, fishing, and processing, in combination with the practical needs of the industry. The aim is to provide support for the transformation of China’s fisheries from a big fishery country to a strong fishery nation.
  • Vitamin C mitigated the effect of hexavalent chromium-induced intestinal microbiota in zebrafish (Danio rerio)
    LU Guanling, NING Jing, RUAN Yuqi, WEI Lu
    Journal of Dalian Fisheries University. 2025, 40(3): 431-439. https://doi.org/10.16535/j.cnki.dlhyxb.2024-141
    Abstract (3241) PDF (537) HTML (5)   Knowledge map   Save
    Hexavalent chromium [Cr(Ⅵ)] is a common and highly toxic environmental pollutant. In this study, we assessed the effects of long-term exposure to environmental concentrations of Cr(Ⅵ) on the intestinal microflora of adult zebrafish (Danio rerio) as well as the effectiveness of the natural antioxidant vitamin C (VC) in preventing chromium oxidative toxicity. Four treatment groups were set up: control (Con) group, VC group (2 mg/L), Cr group (2 mg/L), and Cr+VC group (2 mg/L). After 60 days of semi-static aqueous phase exposure, zebrafish intestines were dissected and feces samples were taken for 16S rRNA high throughput sequencing to analyze the diversity and composition of microbial communities. The results showed that Cr(Ⅵ) induced an increase in Shannon’s index in the intestinal alpha diversity of zebrafish and that the addition of VC reduced this value to some extent (P<0.05). The beta diversity differed between groups in the major components of the gut microbiota (P<0.05). The abundance of species at the phylum and genus levels showed that Cr(Ⅵ) exposure significantly decreased the beneficial bacteria in the genus Cetobacterium (Fusobacteriota) and significantly increased the beneficial bacteria in the genus Exiguobacterium (Firmicutes) in the zebrafish intestine (P<0.05) and that the addition of VC alleviated these changes to a certain extent. Exposure to Cr(Ⅵ) exposure caused the “amino acid transportation and metabolism” function to be slightly lower than that of the Con group, but this function increased slightly after the addition of VC. These results show that VC can alleviate the balance of zebrafish intestinal microflora induced by exposure to Cr(Ⅵ) to a certain extent. The study provides a data support for the remediation of aquatic ecosystems polluted by heavy metals, and it expands the understanding of the structure and function of the zebrafish intestinal microbiota.
  • The influence of light intensity and shelter on habitat and feeding behavior of the spiny lobster (Panulirus homarus)
    TONG Yanling, LIANG Huafang, WEN Chongqing, WANG Chenggui, LI Zhuobo, QING Haipeng
    Journal of Dalian Fisheries University. 2025, 40(3): 382-389. https://doi.org/10.16535/j.cnki.dlhyxb.2024-285
    Abstract (3187) PDF (799) HTML (6)   Knowledge map   Save
    To understand the light adaptation ability and preference for shelters of the spiny lobster (Panulirus homarus), specimens were exposed to different light intensities, light colors, and shelters. The results showed that P. homarus preferred to inhabit low light environments, demonstrating negative phototaxis. They also exhibited a preference for certain light colors. The highest habitation rate (58.61%) occurred in the red light environment and was significantly higher than those of the other three light color groups (P<0.05). Light intensity affected feeding, with greater light intensity resulting in longer time required for the feeding rate to recover. For the 300 lx light intensity experimental group, the feeding rate recovered to 101.0% on day 2, whereas it recovered to only 97.2% on day 6 in the 1 200 lx group. For the four light colors tested, the feeding rate of the lobsters returned to normal levels on day 2. P. homarus showed a preference for low height shelters. The highest habitation rate (66.48%) occurred in shelters located 1 cm from the bottom, and this rate was significantly different from those of the other groups (P<0.05). The lowest habitation rate (0.74%) was recorded in 80 cm high shelters. The lobsters also showed a preference for larger shelters. The highest habitation rate (44.76%) was detected in shelters with a diameter of 20 cm, which was significantly different those of the other groups (P<0.05). These results suggest that P. homarus prefer habitats with weak light and significantly prefer red light. For shelter selection, shelters should be placed at a bottom height not exceeding 40 cm and with a diameter ranging from 0.8 to 1.0 times the length of the antennal flagellum.
  • A study on the ability of Brazilin to penetrate the blood-brain barrier of Nile tilapia (Oreochromis niloticus) in vitro
    ZHENG Mengjie, LI Zixin, CHEN Yanghui, CAI Jia, HUANG Yu, TANG Jufen, MOU Xidong, YANG Yexin, WANG Bei
    Journal of Dalian Fisheries University. 2025, 40(3): 372-381. https://doi.org/10.16535/j.cnki.dlhyxb.2024-237
    Abstract (3171) PDF (817) HTML (6)   Knowledge map   Save
    To explore the ability of Brazilin to penetratethe blood-brain barrier and its potential to treat brain diseases in tilapia, a UPLC-MS/MS analytical method was established for the determination of Brazilin in an in vitro model of the blood-brain barrier of the Nile tilapia (Oreochromis niloticus). The antibacterial efficacy of 36 different Chinese herbal medicines against Streptococcus agalactiae (ZQ0910) was assessed by using the agar diffusion method, and the Minimum Inhibitory Concentration of these extracts was determined using a two-fold dilution technique. Herbs exhibiting significant antibacterial activity were selected for a subsequent in vitro permeability experiment to penetrate blood-brain barrier. The effects of an antibacterial agent on the proliferation of tilapia brain endothelial cells (TVEC-01) and tilapia astrocyte cells (TA-02) were determined using the CCK8 method in a co-culture model of TVEC-01 and TA-02 cells. The effects of bacteriostatic drugs on the expression levels of the tight junction-associated proteins JAM-B, ZO-1, and Claudin-5 in the in vitro blood-brain barrier were then detected using qRT-PCR. Finally, the concentrations of the bacteriostatic drugs in pooled samples from the in vitro blood-brain barrier model were determined using UPLC-MS/MS. The experimental results showed that of the 36 herbs tested in the experiment, the sappan wood aqueous extract had the greatest in vitro inhibitory effect on S. lactis. The results of CCK8 experiment showed that Brazilin in the range of experimental concentrations had no significant inhibitory effect on the growth of the TVEC-01 and TA-02 cells constituting the blood-brain barrier. Concentrations of 20, 40, and 80 μmol/L of Brazilin all regulated down the expression levels of tight junction proteins JAM-B, ZO-1, and Claudin-5 (P<0.05). Brazilin could be detected in samples from the lower pool of blood-brain barrier model after 30-minute administration, and the penetration concentration increased with increase in concentration of drug administered. These findings demonstrate that Brazilin can penetrate the blood-brain barrier and exert antibacterial effects, and provide a feasible strategy for screening drugs to treat brain diseases.
  • Optimization of cultivation conditions for the alga Isochrysis galbana in a pilot-scale tubular photobioreactor
    ZHANG Yao, FAN Chonghui, QIU Zhujun, ZHAO Wenyu, WANG Yuqing, ZHANG Tao, SUN Ziyi, SUN Yan, ZHANG Qian
    Journal of Dalian Fisheries University. 2025, 40(6): 1011-1017. https://doi.org/10.16535/j.cnki.dlhyxb.2025-119
    Abstract (3002) PDF (292) HTML (1)   Knowledge map   Save
    To overcome the shortcomings of traditional microalgae cultivation, such as low biomass concentration and susceptibility to weather conditions, we developed a controlled cultivation system using the alga Isochrysis galbana—a vital microalgal diet for marine aquaculture breeding—as the model species. We used a pilot-scale tubular photobioreactor to optimize light regimes, CO2 supplementation, and cultivation strategies. Regarding the light regime, we found that compared with natural light conditions, supplementary LED lighting at night significantly promoted the growth of I. galbana. Additionally, gradient light supplementation was more conducive to the growth of I. galbana, as we detected 0.38 g/L dry weight,an increase of 11% compared with constant light group after 7 days of cultivation. The average daily light intensity of 150 μmol/m2/s was the optimal condition and the dry weight reached 0.41 g/L. Regarding CO2 supplementation, a high aeration rate (400 mL/min) significantly enhanced growth of I. galbana. Under the same average aeration, the gradient aeration mode was beneficial to stability of the system’s pH. It significantly increased the dry alga yield of I. galbana by 9% compared with the constant light group after 7 days of cultivation. In the semi-continuous cultivation mode, the biomass yield with a 40% renewal rate was much higher than that with a 20% renewal rate. After 14 days of cultivation, 488.32 g of biomass was harvested, 20% higher than that of the 20% renewal rate group. These results show that gradient light regimes, gradient aeration, and semi-continuous cultivation with 40% renewal can significantly enhance the biomass production of I. galbana, thereby providing optimized specifications and technical guidance for industrial-scale microalgae cultivation.
  • DNA methylation in response to environmental stress in aquatic animals： a review
    LI Jin, NIE Hongtao
    Journal of Dalian Fisheries University. 2025, 40(6): 1053-1064. https://doi.org/10.16535/j.cnki.dlhyxb.2025-022
    Abstract (2966) PDF (350) HTML (1)   Knowledge map   Save
    Environmental stress has a significant impact on survival, growth, physiology, and innate immune response of aquatic animals. The innate immune defense system of aquatic animals can quickly respond to environmental stress and help organisms adapt to environmental changes. DNA methylation is an important epigenetic modification.It may dynamically regulate gene expression in aquatic animals facing biotic and abiotic environment stress, participate in metabolism, immunity, and resistance functions, and maintain body homeostasis. This article reviews environmental stress factors, including abiotic factors (temperature, salinity, low dissolved oxygen, pollutants) and biotic factors (viruses, bacteria, parasites); changes in DNA methylation, physiological and ecological effects, and DNA methylation regulation of gene expression in aquatic animals. It provides a scientific reference for a comprehensive understanding of how DNA methylation regulates immunity in the biological response to environmental stress and its potential role in variety breeding and ecological protection.
  • Gene sequence and expression pattern of hsd17b12a in large-scale loach (Paramisgurnus dabryanus)
    FANG Yutong, GUAN Xin, ZHANG Lei, SHI Mijuan, XIA Xiaoqin
    Journal of Dalian Fisheries University. 2025, 40(6): 907-915. https://doi.org/10.16535/j.cnki.dlhyxb.2025-089
    Abstract (2929) PDF (459) HTML (1)   Knowledge map   Save
    The hsd17b12a gene is a key regulator of sex steroid metabolism. To assess the functional mechanism of this gene in large-scale loach (Paramisgurnus dabryanus), we conducted protein prediction and evolutionary analysis based on the full-length coding sequence of hsd17b12a annotated in the genome. The gene's expression patterns were examined using quantitative real-time PCR across embryonic development stages, various adult tissues, and key time points of gonadal development. The results revealed that hsd17b12a has a 949 base pair coding sequence that encodes a 319 amino acid protein. During embryogenesis, its expression was significantly higher at the cleavage stage than that at other stages. The gene was broadly expressed in the heart, liver, spleen, muscle, intestine, gills, brain, and gonads of both sexes, with significantly higher expression in the ovary than that in the testis(P<0.05). These findings suggest that hsd17b12a is closely associated with gonadal development and differentiation in large-scale loach, potentially playing a crucial role in ovarian development while being partially suppressed during testicular development.
  • Nutritional quality and heavy metal safety risk assessment of Chinese mitten crab(Eriocheir sinensis) and crayfish (Procambarus clarkia) cultivated in cold ponds
    WANG Shihui, SU Junjie, ZHANG Shuqi, LUO Liang, ZHANG Rui, GUO Kun, ZHAO Zhigang
    Journal of Dalian Fisheries University. 2025, 40(3): 396-405. https://doi.org/10.16535/j.cnki.dlhyxb.2024-241
    Abstract (2883) PDF (526) HTML (6)   Knowledge map   Save
    To investigate the nutritional quality and heavy metal safety risk of Chinese mitten crab (Eriocheir sinensis) and the crayfish (Procambarus clarkia) farmed in cold ponds with the similar environments, the edible yield, proximate composition(moisture, crude protein, total lipid and ash), fatty acids, mineral elements, and heavy metal (Cd,Cr,Hg and Pb) in these two specieswere determined by dissection, biochemical composition analysis, area normalization, and inductively coupled plasma mass spectrometry. The results showed that the average body weight, gonadosomatic index, meat yield, and total edible yield of E. sinensis were significantly higher than those of P.clarkia (P<0.01). The moisture and crude protein contents in the hepatopancreas of E. sinensis were significantly higher than those of P.clarkia, but the crude protein content in the muscle was significantly lower (P<0.01). The total saturated fatty acid, C18:3n3 (α-linolenic acid), C22:6n3 (docosahexaenoic acid), and total 3-ω polyunsaturated fatty acid contents of E. sinensis were significantly lower than those of P.clarkia (P<0.01), whereas the total polyunsaturated fatty acid content was significantly higher (P<0.01). The contents of Na, Ca, Zn, Cu, and total minerals in the hepatopancreas of E. sinensis were higher than those in the P. clarkia, but the contents of Fe and Mn were lower. The contents of Na, Ca, Fe, Zn, Cu, Mn, Se and total minerals in the muscle of E. sinensis were higher than those in the P. clarkia, but K content was lower (P< 0.01). The contents of the heavy metal elements Cd, Cr, Hg, and Pb in the hepatopancreas and muscle of P.clarkia were slightly higher than those in. In summary, had higher body weight, gonadosomatic index, meat yield, total edible yield, and total PUFA, Na, Ca, Zn, Cu, and total mineral element contents compared to P.clarkia, whereas the edible tissues of P.clarkia had higher α-linolenic acid, docosahexaenoic acid, K contents as well as higher crude protein content in muscle. The poisonous heavy metal contents in the edible tissues of both species were lower than the national food safety standard, making them safe sources of aquatic food.
  • Mechanisms of high-temperature adaptation of Manila clams(Ruditapes philippinarum) during intermediate culture in northern ponds
    DU Zehua, SAIJI Zhuoma, DING Xiangming, ZHANG Guozhu, CHEN Yanyu, XU Yunrui, HUO Zhongming, WANG Hua
    Journal of Dalian Fisheries University. 2025, 40(6): 947-956. https://doi.org/10.16535/j.cnki.dlhyxb.2025-070
    Abstract (2880) PDF (305) HTML (1)   Knowledge map   Save
    The study was to assess the impact of dynamic environmental changes during the summer high-temperature period on physiological metabolism of Manila clams (Ruditapes philippinarum). To assess the metabolic-driven mechanisms underlying the high-temperature adaptation of Manila clams under water quality regulation in intermediate nursery ponds, we systematically monitored individual growth (shell length, wet weight), energy metabolism (oxygen consumption rate, ammonia excretion rate), and key water quality parameters. During the high-temperature window of 27 ℃ to 30 ℃, the clams exhibited significant growth advantages, with a monthly average shell length increase of (3.93 ± 0.21) mm (n= 300). The clams displayed active respiration and metabolism, with oxygen consumption rates ranging from 1.532 to 1.974 mg/(g·h) and ammonia excretion rates between 0.048 and 0.086 mg/(g·h). The oxygen to nitrogen ratio also showed significant temporal variation, indicating dynamic adjustments in metabolic substrate to achieve high-temperature adaptive growth. Additionally, the regular water exchange strategy implemented in the intermediate nursery ponds effectively maintained water quality stability (salinity: 20.6-24.4; dissolved oxygen: 4.72-8.78 mg/L; pH: 7.17-8.37; chlorophyll a: 3.66-16.86 μg/L), providing a suitable environment for clam cultivation. These results demonstrate a “high temperature-high metabolism-stable growth” aquaculture pattern for Manila clams in northern summer nursery ponds, offering technical support for water quality regulation and scientific management in such systems.
  • Effects of glass microbeads on the behavior, gut morphology, and gut microbiota of sea cucumber (Apostichopus japonicus)
    SONG Qiuzhen, YANG Yunjie, WAN Liwei, WU Hengye, ZHAO Chong
    Journal of Dalian Fisheries University. 2025, 40(3): 440-450. https://doi.org/10.16535/j.cnki.dlhyxb.2025-015
    Abstract (2873) PDF (545) HTML (5)   Knowledge map   Save
    A good gut microbiota is of vital importance to digestion of sea cucumber (Apostichopus japonicus). This study used paraffin sectioning, behavioral observation, and 16S rRNA high-throughput sequencing techniques to investigate the effects of ingested glass microbeads on the behavior and intestinal structure of A. japonicus,andthensystematically elucidated the impacts of those microbeads on the composition of intestinal microbial community of sea cucumber. The results showed that no significant differences were observed in crawling and feeding behaviors or gut morphology among group Q (complete replacement of sea mud with microbeads), group I (partial replacement of sea mud withmicrobeads), and group O (control). The abundance and diversity of the gut microbiota of A. japonicus in group Q were significantly higher than those in group O (P<0.05), while no significant difference was observed in the relevant indicators in group I. However, the ingested glass microbeads showed minimal impact on the dominant microbial communities. Proteobacteria were the primary dominant phylum in all three groups, and Bacteroidota persisted as the second dominant phylum, suggesting that the original balance of microbial communities was not disrupted. Compared to group O, group Q exhibited specific bacterial phyla including NB1-j, Hydrogenedentes, and Desulfobacterota, along with specific bacterial families such as the PS1 clade, Hydrogenedensaceae, Hyphomicrobiaceae, and Arenicellaceae.But group I showed no differential bacterial phyla. This study demonstrates that complete substitution of sea mud with glass microbeads in the substrate enhances the richness and diversity of intestinal microbiota of A. japonicus, effectively enriching the beneficial microorganisms while maintaining normal behavioral activities, intestinal structural integrity, and intestinal microecological balance. This study provides theoretical insights for culture of A. japonicus.
  • The effect of Cu2+ stress on the expression of genes related to the immune response and oxidative stress in the kidney of Gymnocypris eckloni
    WANG Lu, JIA Chunyan, LI Changzhong, MA Shuxiong, YAN Weiyi, LIU Zhenya, CHEN Yanxia, ZHANGCAIDAN Zhuoma, JIN Wenjie
    Journal of Dalian Fisheries University. 2025, 40(6): 926-938. https://doi.org/10.16535/j.cnki.dlhyxb.2025-097
    Abstract (2863) PDF (414) HTML (1)   Knowledge map   Save
    The study was to explore the effects of Cu2+ stress on expression of genes related to the immune response and oxidative stress in the kidney of Gymnocypris eckloni. Three-year-old fish were exposed to 0.01 mg/L CuSO4·5H2O for 0, 6, 36, and 72 h respectively. At each time point, the kidney samples were taken, and transcriptomic analysis of kidney tissues was conducted to measure the expression of genes related to immunity and oxidative stress. Six significantly altered immune-related genes (HIF1A, Golph3, Susd2, CXCL8, H2-Eb1, TOP2B) and two significantly altered stress-related genes (INIP and ATP8B2) were detected in the kidneys of G. eckloni under Cu2+ stress. Among them, the expression of HIF1A was significantly up-regulated at 6, 36, and 72 h of Cu2+ stress, but its expression remained stable in the K1, K2, and K3 experimental groups. Golph3 expression was rapidly up-regulated, suggesting that it might be a key early-warning sign of Cu2+ toxicity. Susd2 expression was significantly up-regulated under Cu2+ stress and activated the NF-κB pathway to help the kidney resist heavy metal damage. Expression of CXCL8 was up-regulated at the initial stage of stress, but its expression decreased over time. H2-Eb1 and TOP2B expressions were up-regulated at the early stage and down-regulated at the later stage, respectively. The expression of INIP was significantly down-regulated at the initial stage of Cu2+ stress and significantly up-regulated at 36 h. ATP8B2 expression was normal during the initial phase of stress but suppressed with prolonged stress duration. In conclusion, Cu2+ stress has complex and diverse effects on the expressions of genes related to the immune response and oxidative stress in the kidney of G. eckloni. The changes in the expressions of these genes reflect various adaptation mechanisms and possible damage as the kidney of G. eckloni copes with Cu2+ stress. The research results provide an important theoretical basis for further analysis of the molecular response mechanism of G. eckloni exposed to heavy metal stress and also provide scientific references for protecting this species and other aquatic organisms from heavy metal pollution.
  • Molecular cloning, expression profiling, and functional characterization of the caspase-8 gene in the sea urchin Strongylocentrotus intermedius
    TIAN Ye, LI Yuanxin , QUAN Zijiao, LIU Kexin, XU Haoyuan, LIU Jiaqi, FAN Yichen, HAN Bing, HAN Lingshu, DING Jun
    Journal of Dalian Fisheries University. 2025, 40(6): 897-906. https://doi.org/10.16535/j.cnki.dlhyxb.2025-058
    Abstract (2755) PDF (486) HTML (1)   Knowledge map   Save
    To investigate the role and expression characteristics of the apoptosis-related gene caspase-8 in the immune response of the sea urchin Strongylocentrotus intermedius, rapid amplification of cDNA ends technology, quantitative real-time PCR, and RNA interference were employed. The molecular features of caspase-8 and its encoded amino acids, expression patterns across developmental stages and different tissues, and its biological functions were examined. The full-length caspase-8 cDNA consisted of 3 107 base pairs, with a predicted open reading frame of 2 064 base pairs encoding 687 amino acids. The predicted molecular weight of the protein was 254 700, and the theoretical isoelectric point was 4.85. Caspase-8 exhibited conserved structural features, including two death effector domains(DED) and a cysteine-aspartic acid-specific catalytic domain(CASs). Among the various tissues, caspase-8 expression was highest in coelomocytes and lowest in the intestine. Expression was highest at the 8-cell stage of development and lowest at the gastrula stage. The expression levels of caspase-8 and caspase-3 were assessed following knockdown of caspase-8 with specific small interfering RNA, and the activities of key enzymes were measured before and after interference. Caspase-8 was most efficiently silenced in coelomocytes, and caspase-3 expression levels were significantly downregulated in both the intestine and coelomocytes (P< 0.05), indicating a regulatory relationship between the two genes. In addition, the activities of superoxide dismutase, catalase, peroxidase, and glutathione peroxidase were significantly reduced (P< 0.05), suggesting that silencing caspase-8 may suppress the immune response of sea urchins. This study demonstrates that caspase-8 plays a crucial role in the immune response of sea urchins and that a regulatory association exists between caspase-8 and caspase-3.
  • Development status and future trends in aquaponics technology：a review
    TANG Guangjing, WU Zhengli, SUN Yu, PU Decheng, LI Yanhong
    Journal of Dalian Fisheries University. 2025, 40(3): 529. https://doi.org/10.16535/j.cnki.dlhyxb.2024-183
    Abstract (2694) PDF (794) HTML (4)   Knowledge map   Save
    Aquaponics is a multidisciplinary agricultural technology with the microorganisms as the common productive base. It uses the theory of circular economy to address the problem of environmental pollution and food safety and pursues the goal of green, healthy, and sustainable development in the view of ‘all encompassing approach to food’ concept. Driven by the digital transformation and intelligent applications in recent years, aquaponics technology has experienced significant advances, but still faced many problems and challenges. The paper reviewed the domestic and foreign scientific literature, explored the technical origin of aquaponics development, took the research status of the technical model as the logical line, and clarified the key technical elements, cost-bebefit feasibility, of aquaponics. The technical bottlenecks of aquaponics were analyzed, including limitations relating to salt-alkali water cultivation and breeding varieties, deficiencies in system design, and inadequate supply of artificial light sources.Additionally, challenges such as disease prevention, incomplete purification of recycled water, and a shortage of skilled personnel were also addressed. In view of the analysis above, future research directions should focus on the selection of salt-alkali water cultivation varieties, the transforming mechanisms of nitrogen, phosphorus, and other nutrients, disease prevention and control, and the RD of organic feed. It is forseeable tht that the aquaponics technology will make progress in digitization, artificial intelligence, three dimensionality, and commercialization. This may provide reliable theoretical support for promotion and application of aquaponics technology.
  • Dietary β-hydroxy-β-methylbutyrate supplementation affects growth performance, muscle quality, and glycolipid metabolism in Pacific white shrimp (Litopenaeus vannamei) fed a high carbohydrate diet
    JIANG Shuai, SHUAI Meiqi, XU YiHuan, ZHANG Lihan, FANG Xuedan, GUO Ran, CHEN Guang
    Journal of Dalian Fisheries University. 2025, 40(6): 989-1000. https://doi.org/10.16535/j.cnki.dlhyxb.2025-049
    Abstract (2622) PDF (262) HTML (1)   Knowledge map   Save
    The study was to investigate the effects of dietary supplementation with calcium β-hydroxy-β-methylbutyrate (HMB) in a high carbohydrate diet on growth performance, muscle quality, and glycose-lipid metabolism of Pacific white shrimp (Litopenaeus vannamei). We formulated six isonitrogenous and isoenergetic diets with a high carbohydrate concentration with graded HMB levels of 0, 0.25, 0.5, 1, 2, and 4 g/kg (HMB0, HMB0.25, HMB0.5, HMB1, HMB2, HMB4, respectively). These diets were fed to Pacific white shrimp (initial body weight, 0.28 g ± 0.01 g) for 56 days. Compared to the HMB0 group, the weight gain rate (WGR) and specific growth rate (SGR) of shrimp in the HMB2 and HMB4 groups were significantly higher, whereas the feed conversion ratio was significantly lower. Quadratic regression analysis of the WGR and FCR indices showed that the optimum levels of HMB were 2.58 g/kg and 2.71 g/kg, respectively. Pacific white shrimp in the HMB2 group showed upregulation of key genes in the PI3K/AKT/mTOR signaling pathway and myogenesis regulation in muscle, which improved muscle quality. In the HMB2 group, HMB also downregulated expression of the FoxO1 gene, leading to significant inhibition of gluconeogenesis and lipolysis in shrimp. This further activated glycolysis and enhanced glucose utilization. Furthermore, HMB inhibited lipid synthesis, thereby attenuating high carbohydrate diet-induced lipid deposition in shrimp. In conclusion, dietary supplementation of 2 g/kg HMB in a high carbohydrate diet synergistically improved growth performance, muscle quality, and glucose-lipid metabolism in Pacific white shrimp. These results provide novel insights for promoting the utilization of high carbohydrate diets in the culture of Pacific white shrimp.
  • Review of the effects of net cage biofouling on hydrodynamics in aquaculture environments
    DU Shupeng, LIU Ying, LU Shan, TIAN Zhenglin, REN Xiaozhong
    Journal of Dalian Fisheries University. 2025, 40(6): 1065. https://doi.org/10.16535/j.cnki.dlhyxb.2025-032
    Abstract (2551) PDF (281) HTML (1)   Knowledge map   Save
    As the aquaculture industry moves towards intensive facility-based development and the expansion of nearshore farming to offshore areas, the scale of cage farming continues to increase. In turn, the issue of net biofouling is having an increasingly prominent impact on production. Biofouling is one of the key factors affecting the hydrodynamic characteristics of offshore aquaculture cages. Biofouling organisms not only significantly influence the durability and service life of net structures, but they also play a crucial role in the hydrodynamics of aquaculture environments. This review focuses on the literature related to biofouling of offshore aquaculture nets, specifically on: 1) the impact of net materials on aquaculture environment hydrodynamics; 2) the effects of biofouling on aquaculture environment hydrodynamics, and 3) research methodologies for offshore net biofouling. Current challenges are summarized and future prospects are discussed, with the goal of providing scientific references for understanding biofouling mechanisms and promoting the development of the cage aquaculture industry.
  • Fish feeding intensity recognition based on multi-modal background suppression
    WANG Hao, WANG Miao, LONG Jinlong, HAN Aihui, WU Junfeng, SUN Qunwen, YU Hong
    Journal of Dalian Fisheries University. 2025, 40(3): 499-509. https://doi.org/10.16535/j.cnki.dlhyxb.2024-174
    Abstract (2354) PDF (423) HTML (5)   Knowledge map   Save
    To achieve efficient, accurate, and intelligent fish feeding andto reduce labor intensity and farming cost, this paper proposes a fish feeding intensity recognition method based on a cross-modal background suppression network (CMBS).The CMBS model integrates a cross-modal co-attention mechanism, a multi-head attention fusion module, and both temporal- and event-level background suppression modules. These components enhance the model’s focus on salient features and reduce the influence of transient noise and audio-visual asynchrony often found in single-modality data. To evaluate the effectiveness of the proposed approach, verifying experiments were conducted on two datasets： the publicly available AFFIA3K dataset (collected under controlled laboratory conditions) and a self-constructed dataset obtained from a recirculating aquaculture system (RAS), representing a real-world commercial farming environment. The proposed CMBS model was compared with seven state-of-the-art deep learning models. Experimental results show that the CMBS model achieved a three-class feeding intensity classification accuracy of 98.33% using the AFFIA3K dataset, outperforming traditional single-modal approaches. Using the Pseudocaranx dentex dataset collected in the RAS environment, the model reached an accuracy of 92.20%. These results demonstrate that the CMBS network can achieve high classification performance, and exhibits strong robustness and stability in complex, real-world aquaculture environments.
  • Design of a water quality monitoring system for shellfish purification and temporary rearing
    PAN Lanlan, CHEN Kairui, YU Hankun, ZHOU Yangtao, LIU Hongyuan, ZHENG Yu, FU Xinyuan, ZHANG Guochen
    Journal of Dalian Fisheries University. 2025, 40(3): 510-518. https://doi.org/10.16535/j.cnki.dlhyxb.2024-197
    Abstract (2223) PDF (829) HTML (5)   Knowledge map   Save
    To address the significant water quality fluctuations and delayed oxygenation caused by the high latency of the oxygenation system in the shellfish purification and temporary rearing processes, we designed and made a water quality monitoring system based on the NBIoT communication technology. The system uses a multi-point sensor layout to monitor water quality parameters such as temperature, pH, turbidity, and dissolved oxygen (DO) in real time, and the particle swarm optimization (PSO) algorithm optimizes the back propagation (BP) neural network and the Proportional-Integral-Derivative (PID) controller and builds predicting model for DO and controlling model of automatic aerator. The system uses an STM32 microcontroller as the main control unit for the water quality monitoring sensors,and accomplishes data collection and transmission. Remote communication and data storage have been facilitated through the NBIoT module and the Alibaba Cloud platform. Simulation results showed that the PSO-BP neural network-based dissolved oxygen prediction model had high prediction accuracy, while the PSO-PID controller has improved stability and faster response for aerator control. System testing indicated that the average error in sensor data collection was <5%, confirming high sensor data collection accuracy. This system provides comprehensive, real-time monitoring of water quality throughout the entire process of shellfish purification and temporary rearing, achieving the requirements for water quality monitoring in such applications.
  • Molecular characterization of estrogen receptor genes (esr2a, esr2b) of largemouth bass (Micropterus salmoides) and their mechanism of immunity action
    ZHU Zhilin, GAO Fengying, DONG Junjian, SUN Chengfei, ZHANG Hetong, LI Jiaxin, WANG Qingkui
    Journal of Dalian Fisheries University. 2025, 40(3): 417-430. https://doi.org/10.16535/j.cnki.dlhyxb.2024-246
    Abstract (2110) PDF (449) HTML (5)   Knowledge map   Save
    Estrogen receptors play a crucial role in the reproductive processes of teleost fish. Recent studies have indicated that estrogen signaling pathways are related to immune responses of fish. To investigate the potential immune functions of the estrogen receptor genes 2a (esr2a) and 2b (esr2b) of the largemouth bass (Micropterus salmoides), cDNA fragments of the esr2a and esr2b genes were isolated and their sequence characteristics were analyzed. Expression patterns and temporal expression profiles after injection with Nocardia seriolae, Largemouth bass virus (LMBV), and polyinosinic-polycytidylic acid (Poly I：C), as well as treatment with the exogenous hormone 17β estradiol (E2) were explored.The cDNA sequence of the esr2a gene was 1 912 bp in length, with a 3′untranslated region (UTR) of 113 bp, a 5′UTR of 125 bp, and an open reading frame (ORF) of 1 674 bp, encoding a total of 557 amino acids. The cDNA sequence of the esr2b gene was 2 358 bp in length, with a 3′UTR of 293 bp, a 5′UTR of 52 bp, and an ORF of 2 013 bp, encoding a total of 670 amino acids.Both the esr2a and esr2b proteins in the largemouth bass were characterized as unstable, hydrophilic, and acidic. In addition, both esr2a and esr2b contained one ZnF_C4 domain and one HOLI domain. Real-time fluorescence quantitative PCR analysis showed that, in normal fish, the esr2a gene exhibited its highest expression in kidney, while the esr2b gene showed its highest levels in spleen and liver. Following injection with N. seriolae, significant decreases in the expression levels of the esr2a and esr2b genes were observed in the liver of largemouth bass (P<0.05). Conversely, after injection with LMBV, the expression levels of the esr2a and esr2b genes in the kidney increased significantly (P<0.05). In contrast, injection with Poly I：C significantly inhibited the expression of esr2a and esr2b in both the kidney and spleen (P<0.05). Additionally, E2 treatment inhibited the expression of the esr2a and esr2b mRNAs in the spleens of both male and female fish (P<0.05). This study suggests a potential association between the esr2a and esr2b genes and the immune response in largemouth bass.
  • The direct antibacterial function and mechanism of interleukin-8 in mandarin fish (Siniperca chuatsi)
    YANG Jie, MA Xiaojie, LI Chao, CHEN Shannan, NIE Pin, HUO Huijun
    Journal of Dalian Fisheries University. 2025, 40(6): 957-963. https://doi.org/10.16535/j.cnki.dlhyxb.2025-078
    Abstract (2107) PDF (385) HTML (1)   Knowledge map   Save
    To investigate the direct antibacterial function and mechanism of interleukin-8 (IL-8) obtained from mandarin fish (Siniperca chuatsi), we analyzed its molecular physicochemical properties and structural characteristics. The recombinant protein was prepared through prokaryotic expression, and its direct antibacterial effects on model pathogen strains and fish pathogenic bacteria were tested. To assess the antibacterial mechanism of IL-8, flow cytometry was used to detect changes in bacterial membrane permeability and membrane potential. The results showed that the net charge of the mature peptide region of mandarin fish IL-8 was +4.1, conferring cationic properties. The positively charged amino acids and hydrophobic residues on the molecular surface were clustered in distinct regions, endowing the molecule with amphipathicity. These cationic and amphipathic features provided the structural basis for the direct antibacterial activity of mandarin fish IL-8. The recombinant IL-8 protein also exhibited significant growth inhibitory effects against model strains such as Escherichia coli and Staphylococcus aureus and against fish pathogens like Aeromonas hydrophila, Aeromonas media, and Streptococcus agalactiae. Inhibitory effects were detected at 4 μmol/L and complete inhibition of bacterial growth occurred at 32 μmol/L, demonstrating direct antibacterial function. Flow cytometry revealed that bacteria treated with mandarin fish IL-8 showed significantly enhanced staining with the membrane impermeability probe and the membrane potential probe, indicating that mandarin fish IL-8 may increase membrane permeability and induce membrane depolarization, thereby having a direct destructive effect on bacterial membranes. These results suggest that mandarin fish IL-8 exerts its direct antibacterial function by disrupting bacterial membranes.
  • The inhibitory effect and mechanism of thymol against bacterium Aeromonas hydrophila
    LI Luning, LI Junyi, REN Xinyu, LIU Bingyu, ZHOU Jiachen, XU Dan, ZHANG Ye
    Journal of Dalian Fisheries University. 2025, 40(6): 964-972. https://doi.org/10.16535/j.cnki.dlhyxb.2025-023
    Abstract (2081) PDF (430) HTML (1)   Knowledge map   Save
    The study was to investigate the in vitro antibacterial effects of thymol against the bacterium Aeromonas hydrophila and to elucidate the potential mechanisms of action. We determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of thymol against A. hydrophila, plotted the bacterial growth curve, measured the fluorescence intensity of 1-N-phenylnaphthylamine(NPN) and propidium iodide(PI), observed bacterial morphology using scanning electron microscopy, quantified intracellular protein and DNA leakage, and assessed swarming motility. The MIC and MBC of thymol against A. hydrophila were 125 mg/L and 500 mg/L, respectively. At a concentration of 1 MIC, thymol completely inhibited the growth and reproduction of A. hydrophila within 24 h. Additionally, thymol effectively disrupted both the inner and outer membrane structures of A. hydrophila, leading to leakage of intracellular macromolecules. The extent of leakage was significantly and positively correlated with both the concentration of thymol and duration of exposure. Thymol also inhibited the swarming motility of A. hydrophila, thereby reducing the risk of biofilm formation and subsequent colonization on host surfaces. These results show that thymol possesses substantial antibacterial and bactericidal activities against A. hydrophila and that these effects are primarily achieved through the disruption of both the inner and outer membrane structures of A. hydrophila, leading to alterations in bacterial morphology, leakage of cellular contents, and bacterial death. They also contribute a critical theoretical foundation for investigating thymol as a potential alternative to antibiotics for controlling pathogenic bacterial infection.
  • The influence of hemoglobin residue on the frozen fish meat quality of fat greenling (Hexagrammos otakii)
    MAO Xiaocong, WU Fangbing, WANG Jiayan, SHI Feilong, TIAN Yuanyong, ZHAO Hui, LU Hang
    Journal of Dalian Fisheries University. 2025, 40(6): 1028-1039. https://doi.org/10.16535/j.cnki.dlhyxb.2025-064
    Abstract (1986) PDF (281) HTML (1)   Knowledge map   Save
    To explore the effect of hemoglobin residue on the meat quality of frozen fat greenling(Hexagrammos otakii), two groups of fish were killed respectively using brainstem bloodletting or fish head tapping. The hemoglobin residues in frozen fish meat were compared between two groups. The change of hemoglobin, meat quality, and oxidation of lipids and proteins in frozen fish meat at 4 ℃ were analyzed and compared. The results showed that the hemoglobin content was reduced approximately 30% in the frozen fish killed by brainstem bleeding, and that it gradually decomposed and its content continued to decrease. During the 5-day refrigeration process, the hemoglobin content of fish meat in the bleeding and non-bleeding groups decreased from 12.86% to 4.65% and from 16.96% to 5.98%, respectively. The content of heme, a decomposition product of hemoglobin, gradually increased over time and then degraded. The content of oxygenated hemoglobin in the fish meat of the bleeding and non-bleeding groups decreased from 14.76% to 0.65% and from 16.86% to 1.08%, respectively, while the content of methemoglobin increased from 9.81% to 23.22% and from 14.88% to 25.22%, respectively. This pattern indicates that oxygenated hemoglobin was transformed into methemoglobin. Compared with the meat from the bleeding fish, the contents of hemoglobin, heme, free iron, Fe2+ and Fe3+ in the meat of the non-bleeding fish were significantly higher. During the 5-day refrigeration storage, the brightness(L*) and redness(a*) values showed an upward trend, while the yellowness(b*) value showed a downward trend. Over time, the peroxide values(POV) of the bleeding and non-bleeding groups increased by 0.83 μg/100 g and 1.11 μg/100 g, respectively, and the mass fraction of malondialdehyde increased by 0.22 μg/100 g and 0.31 μg/100 g. The carbonyl content of fish meat from the two groups increased by 3.16 nmol/mg and 6.21 nmol/mg, respectively, and the thiol content decreased by 4.04 nmol/mg and 7.32 nmol/mg. In summary, bleeding killing method delayed the decline in meat quality and reduced the oxidation degree of lipids and proteins in frozen fish meat. Correlation analysis indicated that the oxidative degradation of hemoglobin in fish meat during refrigeration intensified the occurrence of lipid oxidation and protein oxidation, which in turn significantly affected the rate of deterioration of the frozen fish meat.
  • Influence of salinity on growth, blood biochemistry, tissue structure and antioxidantcapacity of juvenile Amur whitefish (Coregonus ussuriensis)
    ZHENG Hao, LIU Enhui, HUANG Tianqing, GU Wei, WANG Gaochao, GE Kaibo, FAN Peng, SUN Yunchao, LI Datian, WANG Xinyang, WANG Junwei, XU Gefeng
    Journal of Dalian Fisheries University. 2025, 40(6): 939-946. https://doi.org/10.16535/j.cnki.dlhyxb.2025-136
    Abstract (1964) PDF (382) HTML (1)   Knowledge map   Save
    The study was to investigate influence of different salinities on growth performance, blood physiological indicators, and antioxidant systems of Amur whitefish (Coregonus ussuriensis). Juveniles C. ussuriensis with an initial weight of 35.0 g± 1.5 g were divided into five groups： control (freshwater, salinity 0) and salinities of 8, 16, 24, and 36. The fish survival rates and growth indicators of each group were measured and compared. After 30 days of salinity acclimation, physiological index measurements and tissue structure observations were made to assess physiological responses of fish to different salinities. The fish cultured at salinities <24 showed good growth performance, and the survival rate significantly dropped to 21.4% of fish cultured at salinity 32. The plasma osmolality, blood glucose level, and concentrations of ions such as Na+, Cl-, and Mg2+ gradually increased with an increase in salinity and reached a significantly different level at salinity 32. Under the high salinity (32), the gill and liver tissues were severely damaged, as indicated by severe vacuolation. Superoxide dismutase(SOD), catalase(CAT), and glutathione peroxidase(GSH-Px) activities gradually and significantly increased with an increase in salinity. These results indicate that the suitable salinity for breeding and stocking C. ussuriensis is from 0 to 24. Beyond this range, salinity will have a significant negative impact on survival and physiological health of this species.
  • A study on the underwater fish recognition method based on deep subtle features capture
    CHEN Yuwei, ZHU Xiaolong, LI Chaofan, CHU Wenjing, CHEN Zongyi, ZHANG Zhenyu
    Journal of Dalian Fisheries University. 2025, 40(3): 489-498. https://doi.org/10.16535/j.cnki.dlhyxb.2024-204
    Abstract (1888) PDF (620) HTML (5)   Knowledge map   Save
    We proposed a deep subtle feature extraction-based underwater fish recognition method (DFFE-Net) to enhance the recognition capability in the complex underwater environments. This method uses YOLOv8 as the base model due to its robustness and deformable convolution DCNv4 to replace traditional convolutions, forming the EDCN module to capure, subtle features from deep characteristic image. The Shape IoU algorithm is employed to optimize the positioning of bounding boxes, thereby enhancing the precision of fish localization. Comparative experiments using a self-built underwater fish image dataset were conducted to test the model. The experimental results indicated that the proposed DFFE-Net can enhance the mAP_50, mAP_75, and overall mAP of underwater fish recognition to 95.1%, 87.2%, and 80.3%, respectively, without increasing the parameter count or computational load. Thus, DFFE-Net can provide technical support for intelligent and precise.
  • Comparative study on tissue indices and biochmemical composition between the normal Chinese mitten crabs (Eriocheir sinensis) and the abnormal crabs
    WU Yuting, ZHANG Dongdong, SU Qiling, SUN Qiufeng, WU Xugan
    Journal of Dalian Fisheries University. 2025, 40(6): 1001-1010. https://doi.org/10.16535/j.cnki.dlhyxb.2024-184
    Abstract (1874) PDF (298) HTML (1)   Knowledge map   Save
    We compared characteristics of healthy Chinese mitten crabs (Eriocheir sinensis) with abnormal crabs (shuibiezi crab) affected possibly by hepatopancreatic necrosis syndrome. Utilizing anatomical and biochemical analysis methods, we measured tissue indices, color parameters, carotenoid content, proximate composition, and fatty acid composition of the two groups of crabs. The hepatosomatic index (HSI), gonadosomatic index (GSI), muscle yield (MY), and total edible yield (TEY) of the abnormal group were significantly lower than those of the normal group (P< 0.01). The L*, a*, and b* values of the wet hepatopancreas samples from male and female abnormal crabs were significantly lower than those from normal crabs (P< 0.01). The contents of lutein and β-carotene in ovaries of female crabs from the diseased group were notably lower than those in the normal group. Similarly, the total carotenoid and β-carotene levels in the hepatopancreas of diseased male crabs were significantly lower than those in the normal male group (P< 0.05). The moisture contents in the hepatopancreas and gonads of the diseased group were significantly higher than those in the normal group. In contrast, the total lipid content of hepatopancreas was significantly lower in the diseased group compared with the normal group (P< 0.05). While the levels of C20:2n6 and C20:5n3 were notably higher in the hepatopancreas of the diseased group compared with the normal group, the C16:1n7 and DHA/EPA ratio were significantly lower in the diseased group (P< 0.05). In summary, shuibiezi crabs exhibited high moisture content in edible tissues, low muscle and gonadal protein content, an unbalanced fatty acid composition, and overall low nutritional value. Moving forward, enhancing nutritional regulation may be a crucial measure to prevent and control “shuibiezi” disease in Chinese mitten crabs.
  • Prediction of bigeye tuna (Thunnus obesus) fishing ground in the Atlantic Ocean based on the modified XGBoost model
    ZHOU Shuting, ZOU Xiaorong, ZOU Bangyu
    Journal of Dalian Fisheries University. 2025, 40(3): 481-488. https://doi.org/10.16535/j.cnki.dlhyxb.2024-254
    Abstract (1863) PDF (357) HTML (5)   Knowledge map   Save
    To predict accurately the bigeye tuna fishing ground and thus to reduce fishing cost effectively, we utilized the fishing operation data on the Chinese tuna longline fishing vessels in the Atlantic during the period of 2018 to 2021 and marine environmental data concurrently. Based upon the Extreme Gradient Boosting (XGBoost) model, we incrementally integrated Convolutional Neural Network (CNN) models and the Simulated Annealing (SA) algorithm to build XGBoost, CNN-XGBoost, and CNN-SA-XGBoost models to predict bigeye tuna fishing grounds in the Atlantic Ocean and compared the predictive performance of these models. The results indicated that the CNN-SA-XGBoost model achieved an accuracy (ACC) of 82% and an area under the receiver operating curve (AUC) of 0.81, which represents 15% and 6% increases in accuracy and 0.10 and 0.02 increases in the AUC compared with the XGBoost and CNN-XGBoost models, respectively. In the analysis of the importance of environmental factors by CNN, chlorophyll concentration (Chl-a), surface seawater temperature (T0), surface seawater salinity (S0), and 300 m depth salinity (S300) accounted for approximately 51% of the relative importance index, identifying them as key environmental factors affecting the catch and distribution of bigeye tuna. In summary, the CNN-SA-XGBoost model demonstrates strong accuracy, balance, and adaptability, suggesting it suitable for forecasting bigeye tuna fishing grounds in the Atlantic Ocean.
  • Expression of the opa1 gene of medaka (Oryzias latipes) and its potential role in sex differentiation of male and female gonads
    LI Chenjie, QIAN Feng, CHEN Juan, YU Shiqi, GUAN Guijun
    Journal of Dalian Fisheries University. 2025, 40(6): 916-925. https://doi.org/10.16535/j.cnki.dlhyxb.2025-084
    Abstract (1610) PDF (413) HTML (1)   Knowledge map   Save
    To explore how the gonadal soma-derived factor (gsdf) affects dynamic changes in mitochondrial morphology and metabolism in medaka(Oryzias latipes), we applied transcriptomics and quantitative real-time PCR to analyze the differential expression of the optic atrophy gene 1 (opa1) in various tissues of male and female deletion of gsdf (gsdf-/-) and wild-type (gsdf+/+) medaka. Opa1 encodes an inner mitochondrial membrane fusion protein. Its expression in gsdf-/- testes was significantly elevated, whereas little difference in expression was detected between wild-type and gsdf-/- ovaries. Opa1 mRNA was widely expressed in multiple tissues of wild-type adult medaka, with the highest expression level in the testes. Proportional comparison of the long isoform of opa1 (L-opa1) in the gonads of gsdf+/+ and gsdf-/- medaka revealed that the level of its mRNA was significantly decreased in the testes of gsdf-/- medaka. This low expression in the testes of gsdf-/- medaka suggests that the gsdf signal may be involved in the stimulation of L-opa1 expression or L-opa1 mRNA maintenance, thereby maintaining normal mitochondrial cristae structure in germ cells. Transmission electron microscopy revealed that only some of the mitochondria had abnormal cristae structure in gsdf-/- male germ cells. Combined with the observation of altered L-opa1 mRNA proportion in gsdf-/- XX and XY gonads, these findings imply the presence of at least two types of mitochondria, namely those that are sensitive or insensitive to the gsdf signal. We hypothesize that dynamic changes in mitochondrial energy metabolism in germ cells may drive dynamic alterations in autosome-sex chromosome pairing and meiotic homologous recombination. Our results support the premise that dynamic changes in mitochondrial metabolism may be an important driving force promoting the differentiation and healthy development of male and female germ cells. They also show that the shaping of diversified sex chromosomes with different autosomal origins in various species accompanying species evolution may be a common result of germ cell fertility changes caused by mitochondrial oxidative phosphorylation metabolism.
  • Large scale artificial propagation technology and observations on the embryonic development of Pseudorasbora parva
    MO Yanfang, LUO Xiaonian, DUAN Youjian, LI Jiao, LI Jianqiao, KANG Junlong, DONG Ruixin, SUN Rongzhen
    Journal of Dalian Fisheries University. 2025, 40(4): 607-617. https://doi.org/10.16535/j.cnki.dlhyxb.2025-004
    Abstract (1489) PDF (529) HTML (0)   Knowledge map   Save
    To achieve the largescale production of Pseudorasbora parva, a comparative study of P. parva reproductive technologies was conducted at the Xingda Farm in Liaoyang County from 2023 to 2024. Oxytocin dosages, injection methods, interval of injections, optimum water temperature for estrus, changes in sperm motility of male fish injected with aphrodisiacs, and five methods to extract eggs and two methods of hatching management were assessed. The results showed that the peak breeding period of P. parva in the Liaoyang area, was from early April to early June. The maturity rate of the fish was 291.41%. When LHRH-A2 8 μg/kg+HCG 2 000 IU/kg was injected, the highest level of oxytocin was achieved, reaching 63.00%±5.77%. The highest level of oxytocinoccurred when the water temperature was 17 ℃, and the time between the two injections was 8 h, resulting in an effect time of 23-36 h. The time for sperm to move rapidly reached the maximum of (89.50±0.50) s at 16 h after P. parva males were injected with oxytocic drugs.At 24 h, the life-time of sperm reached its maximum of (132.00±15.04)s. Of the five artificial spawning substrates tested, sieve cloth achieved the highest egg adhesion rate of 98.00%±0.02%. Of the two hatching methods, incubation baskets significantly outperformed static aerated plastic basins (P<0.05). In 2024, three oxytocic production batches under the optimized conditions yielded 400 000 eggs and 255 000 fry. The elliptical yellowish adhesive eggs of were measured (1.08±0.23) mm pre-hydration, expanding to (1.68±0.13) mm post water-absorption. Embryonic development progressed through 27 stages across 7 phases (blastodisc formation, cleavage, blastula, gastrula, neurula, organogenesis, and hatching). At 18 ℃-21 ℃, hatching took 199 h 58 min with a total accumulated temperature of hatching of 3 811.62 ℃/h. The total length of newly hatched larvae was (5.01±0.32) mm, and horizontal swimming and readiness for releasing to pond was achieved within 3-4 days post-hatching. This study shows that large-scale artificial propagation of P. parva may be achieved by artificially controlling the type dosage and injection methods of oxytocic drugs.
  • Temporal and spatial distribution of macrozoobenthic communities and their relationship with environmental factors in Qiandao Lake, China
    SUN Qihao, ZHANG Jingwen, LIU Qigen, HU Zhongjun, SHAO Jianqiang, PAN Jiayong, HE Guangxi
    Journal of Dalian Fisheries University. 2025, 40(6): 1018-1027. https://doi.org/10.16535/j.cnki.dlhyxb.2024-218
    Abstract (1480) PDF (221) HTML (1)   Knowledge map   Save
    To investigate temporal and spatial distribution patterns of macrozoobenthic communities in Qiandao Lake, Zhejiang Province, China and to explore the key environmental factors influencing their distribution, macrobenthos were collected from 25 sampling stations from December 2020 to October 2021. Eighteen species of macrozoobenthos were identified and classified into three phyla and four classes. The most macrozoobenthos species in Qiandao Lake (88.89%) belonged to Oligochaeta and Insecta, with nine and seven species, respectively. Limnodrilus hoffmeisteri and Tubifex tubifex were the dominant species throughout the year. The annual average density and biomass of benthic macroinvertebrates were 611.1 ind./m2 and 1.45 g/m2, respectively. No significant seasonal differences in density and biomass were detected by two-way analysis of variance, but there were significant spatial differences. Correlation analysis showed that spatial differences were primarily positively correlated with pH, total dissolved solids (TDS), specific conductance (SPC), nitrite nitrogen  total nitrogen (TN), and/or the permanganate index (CODMn) and negatively correlated with water transparency. The explanatory variables for density and biomass varied along different flow directions. Redundancy analysis results indicated that soluble phosphate  water temperature (WT), TDS, TN, water depth (WD), CODMn, and pH were the key factors influencing the spatial and temporal distribution of benthic macroinvertebrate communities in Qiandao Lake (P<0.05). L. hoffmeisteri, Limnodrilus claparedeianus, and T. tubifex exhibited significant positive correlations with pH, CODMn,  TN, and WT. In contrast, the insect Procladius choreus and oligochaetes Branchiura sowerbyi and Aulodrilus pluriseta showed significant negative correlations with WT, TSD, and WD. The results also showed that primary productivity was a key driver of spatial variations in macrobenthic abundance in Qiandao Lake and that most of the Lake was in a lightly polluted state, with good water quality in general.
  • Estimation of the carrying capacity of the marine area off Dongying City, Shandong Province for the Zebra Ⅱ strain of the Manila clam (Ruditapes philippinarum)
    LI Yunzhi, WANG Fan, LI Cuicui, QIN Lizhao, YANG Guojun, GU Jing, LI Zhengyuan, ZHANG Gang , YU Liangju, WANG Hua, HUO Zhongming, YANG Feng, YAN Xiwu
    Journal of Dalian Fisheries University. 2025, 40(5): 742-750. https://doi.org/10.16535/j.cnki.dlhyxb.2025-009
    Abstract (1421) PDF (247) HTML (0)   Knowledge map   Save
    To optimize large-scale cultivation of the Zebra Ⅱ strain of the Manila clam (Ruditapes philippinarum) in the intertidal zones and offshore area of Shandong Province, sampling stations were established in the Hekou shellfish farming region in Dongying City, Shandong Province. Based on an annual survey of indicators such as chlorophyll-a (Chl-a) and primary productivity (PP) in the survey area combined with laboratory-measured filtration rates and other relevant parameters, the carrying capacity of Zebra Ⅱ strain in this marine area was estimated. The annual average Chl-a concentration in the surveyed area was (3.55±0.27) mg/m3, with a range of 1.54 to 5.41 mg/m3. There was no significant difference in horizontal distribution between the intertidal zone and the offshore area (P>0.05). Seasonally, the intertidal zone exhibited greater fluctuations in Chl-a levels, while the offshore area remained relatively stable. Overall, the average Chl-a concentrations in the clam farming area during summer and autumn were significantly higher than those in winter and spring (P<0.05). The annual average PP in the marine area was (199.46 + 138.89) mg C/(m2·d), with a range of 35.6 to 597.81 mg C/(m2·d). The intertidal zone had significantly higher PP than the offshore area (P<0.05), and the average PP in summer was significantly higher than that in winter (P<0.05). Laboratory experiments demonstrated that under an average water temperature of 14.2 ℃, the average filtration rate of Zebra Ⅱ strain clams was 1.43 L/(g·h) (dry weight). Estimation with the Herman model revealed that under the nutrient conditions (Chl-a and PP) studied, the carrying capacity of the marine area was higher in summer and autumn than in winter and spring. A conservative estimate of average carrying capacity for this strain of Manila clam (with a shell length of 3 cm) based on summer and autumn averages was 258 ind./m2, with values of 55 ind./m2 in the intertidal zone and 461 ind./m2 in the offshore area. Relative to the Herman model values, the estimated carrying capacity estimated by using the food-limitation index (Dame’s method) was higher in the intertidal zone and lower in the offshore area. The results of this study suggest that in the intertidal zone of the Hekou coastal area of Dongying City, Shandong Province, the Zebra Ⅱ strain may be cultivated at densities moderately higher than 55 ind./m2, while densities should be kept moderately lower than 461 ind./m2 in the offshore area. Stocking densities should be dynamically adjusted based on the calm growth performance of the clams and the water quality conditions during cultivation, with the aim of maintaining high yields while ensuring the relative stability of the marine ecosystem and achieving sustainable development.
  • Cloning the OSCP subunit gene of Macrobrachium rosenbergii and assessing its influence on the structure of ATP synthase
    CHEN Xin, DAI Xilin, JIA Chuipan, DONG Wangming, HE Bo, LUO Zhenhui, BU Xiaoyang
    Journal of Dalian Fisheries University. 2025, 40(3): 363-371. https://doi.org/10.16535/j.cnki.dlhyxb.2024-170
    Abstract (1392) PDF (641) HTML (8)   Knowledge map   Save
    To investigate the role of the oligomycin sensitivity-conferring protein (OSCP) subunit gene of ATP synthase in the structural integrity and functional stability of ATP synthase in the freshwater prawn Macrobrachium rosenbergii, its full-length cDNA was cloned by using rapid amplification of cDNA ends(RACE) technology. Small interfering RNA (siRNA) was used to interfere with the expression of the OSCP subunit gene, and the resulting changes in the expression levels of other ATP synthase subunit genes were explored. The results showed that the full-length cDNA of the OSCP subunit gene of ATP synthase in M. rosenbergii is 922 base pairs long and encodes a hydrophobic protein consisting of 209 amino acids. Homology comparison and genetic relatedness analysis indicated that the OSCP subunit gene in M. rosenbergii has the highest homology and closest genetic relationship with the American lobster (Homarus americanus). Quantitative PCR analysis of tissue samples revealed that the expression level of the OSCP subunit gene was highest in the heart. The optimal injection dose of siRNA was 1.2 μg/g. When the expression of the OSCP subunit gene in the heart of M. rosenbergii was downregulated, the expression levels of the α, β, γ, δ, b, and d subunit genes of ATP synthase decreased significantly (P<0.05). This result indicates that inhibition of the expression of the OSCP subunit gene affects the expression of other subunit genes, thereby influencing the synthesis of ATP synthase.
  • Molecular cloning of lymphocyte cytosolic protein 1 (LCP1) gene in Nile Tilapia (Oreochromis niloticus) and its role in the immune response against Streptococcus agalactiae
    LI Weifu, YUAN Jiayi, ZHANG Xiangdong, WANG Zhiwen, XIA Hongli, LU Yishan
    Journal of Dalian Fisheries University. 2025, 40(5): 761-770. https://doi.org/10.16535/j.cnki.dlhyxb.2025-043
    Abstract (1376) PDF (233) HTML (0)   Knowledge map   Save
    To investigate molecular characteristics of the Nile tilapia (Oreochromis niloticus) lymphocyte cytosolic protein (LCP1) gene and its potential function in the immune response against Streptococcus agalactiae, the gene encoding LCP1 from Nile tilapia was successfully cloned (OnLCP1). Bioinformatics analysis was conducted on this gene, and its subcellular localization was determined. The expression pattern of OnLCP1 mRNA in various tissues after S. agalactiae stimulation was analyzed by using fluorescence quantitative PCR. A dual luciferase reporter gene assay was used to detect the impact of transcription factors such as NF-κβ, STAT1, ISRE, IFN-1, and IFN-3 on promoter activity of the LCP1 gene. The results showed that OnLCP1 consists of 1857 base pairs and encodes a 618-amino acid protein. The OnLCP1 protein contains an EF-hand domain (calcium binding domain) and two tandem actin binding domains(ABD), with each actin domain containing two calmodulin homology(CH) domains. OnLCP1 is an extracellular protein without the transmembrane region, and it shares a highly similar three-dimensional structure with the human LCP1 protein, suggesting that its function may be conserved. OnLCP1 was expressed in various tissues of healthy Nile tilapia, with the highest expression level in the spleen. After stimulation by inactivated S. agalactiae, the expression of the OnLCP1 gene in immune organs significantly increased, indicating its potential involvement in the immune response against pathogenic bacteria. The subcellular localization experiment showed that OnLCP1 was expressed in the cytoplasm of HEK-293T cells. The dual luciferase reporter gene experiment showed that the OnLCP1 gene significantly activates the NF-κβ signaling pathway (P<0.05), suggesting that OnLCP1 may mediate defense against S. agalactiae infection through this pathway. The results of this study provide a scientific ground for further research of LCP1 function in the innate immunity of fish.
  • Research progress on aquaculture biology of Phoxinus lagowskii：a review
    LUO Xiaonian, DUAN Youjian, BAI Xiaohui, WU Chen, LI Jiao, YANG Peimin, JIN Guanghai
    Journal of Dalian Fisheries University. 2025, 40(6): 1040-1052. https://doi.org/10.16535/j.cnki.dlhyxb.2025-056
    Abstract (1365) PDF (315) HTML (1)   Knowledge map   Save
    Phoxinus lagowskii is a sub-cool small fish that normally lives in low water temperature rivers. It is one of important freshwater economic fish species in China and has become a key aquaculture species in northern regions in recent years. Significant research progress has been made in the field of its aquaculture biology. This paper elaborates on the sysematics and morphological characteristics of Phoxinus lagowskii, and reviews the advances in studies on its biological traits, including reproductive capacity, sperm biology, oxygen consumption rate and asphyxiation point, molecular mechanisms of hypoxia tolerance, light preference, and temperature adaptability. It also summarizes key aspects of artificial breeding technology, embryonic development, juvenile development, fry cultivation, adult fish farming, feed nutritional requirements, disease prevention and control, as well as genetic characteristics. Based on the current status of Phoxinus lagowskii aquaculture, the paper explores future research directions in its aquaculture biology to provide a systematic theoretical foundation for optimizing large-scale farming technology, promoting genetic improvement and breeding, and fostering the healthy development of Phoxinus lagowskii aquaculture industry.
  • Qualitycontrol and data lifecycle management for farmed fish datasets
    GU Xiaowei, ZHANG Shengmao, YANG Shenglong, WU Zuli
    Journal of Dalian Fisheries University. 2025, 40(5): 873-886. https://doi.org/10.16535/j.cnki.dlhyxb.2025-200
    Abstract (1327) PDF (288) HTML (0)   Knowledge map   Save
    Aquaculture industry is transformed towards artificial intelligence and high-qualtiy datasets are cornerstone to promote the development of digital intelligence fisheries.We systematically reviewed the construction pipeline, data types, key technologies, and quality control methodologies for farmed fish datasets.First, we summarized and analyzed the application characteristics and associated challenges of diverse data types, including images, videos, audio, 3D point clouds, and text, within intelligent aquaculture.Second, the technical frameworks for key processes, such as data acquisition, annotation, augmentation, and multi-modal fusion, were elaborated.Third, we constructed a full life cycle data quality control and standardization mechanism that addressed dimensions such as acquisition quality, annotation consistency, and structural standardization.Finally, the characteristics and limitations of typical open source datasets were summarized. Building upon cutting-edge technologies such as self-supervised learning, federated machine learning, and digital twins, we concluded by proposing future research directions for farmed fish datasets. The research result provides systematic data support and methodological references for both the research and practice of intelligent aquaculture.
  • Isolation and application of a beneficial intestinal bacterium Bacillus flexus from Apostichopus japonicus
    ZHAO Xinyan, LIU Shang, LI Jiaxi, CHEN Yingxu, GUAN Hui, ZHAO Chenyang, LI Yongming, HUO Zhongming, FANG Lei
    Journal of Dalian Fisheries University. 2025, 40(4): 565-574. https://doi.org/10.16535/j.cnki.dlhyxb.2025-025
    Abstract (1319) PDF (381) HTML (0)   Knowledge map   Save
    Bacteria beneficial to the growth of the sea cucumber Apostichopus japonicus were isolated from the intestines of healthy individuals. Strains producing protease, lipase, and amylase were screened by using selective media, and their enzymatic activities were subsequently verified. Further evaluations included tests for antibiotic sensitivity and tolerance to acids and bile salts. The strains were identified based on morphological characteristics and full-length 16S rDNA sequencing. Safety and aquaculture experiments were conducted to assess their growth-promoting effects on A. japonicus. One strain, designated AC27 was successfully isolated and found to be capable of simultaneously producing protease, lipase, and amylase.AC27 exhibited no β-hemolytic activity, demonstrated high sensitivity to multiple antibiotics, and was able to grow under conditions of pH 3.0 and 0.7% bile salt concentration.Morphological and 16S rDNA sequencing analyses identified AC27 as Bacillus flexus. Pathogenicity tests confirmed that AC27 was non-pathogenic to A. japonicus. Immersion culture experiments demonstrated that it significantly enhanced the weight gain rate and specific growth rate of A. japonicus (P<0.05) while reducing the coefficient of variation in body weight. In conclusion, B. flexus AC27, isolated from the intestines of healthy A. japonicus, is safe, reliable, and exhibits significant growth-promoting effects.This study highlights the potential of B. flexus as a valuable candidate for developing probiotics tailored for A. japonicus.
  • Degradation activity and structure analysis of the anaerobicmicrocystin-degrading bacterial community in a shrimp pond
    SHI Zecheng, WANG Xinyu, BI Xiangdong, DAI Wei, YANG Jinghua
    Journal of Dalian Fisheries University. 2025, 40(6): 982-988. https://doi.org/10.16535/j.cnki.dlhyxb.2024-006
    Abstract (1302) PDF (256) HTML (1)   Knowledge map   Save
    To understand the anaerobic degradation of microcystin (MCs) by microorganisms in anoxic environment of shrimp culture ponds in summer, samples of overlying water, sediment and shrimp were collected from a Litopenaeus vannamei culture pond. The accumulation of MCs in samples was analyzed. The anaerobic MCs-degrading bacterial communities in sediment and shrimp intestine were continuously enriched, and their community structures and degradation activities were analyzed. The results showed that there were soluble MCs in overlying water. MCs accumulation could be detected in pond sediment, hepatopancreas and muscle of shrimp. Anaerobic MCs-degrading bacterial community existed in both pond sediment and shrimp intestine. Kosakonia became the dominant bacteria after 4 times of enrichment in pond sediment and 2 times of enrichment in shrimp intestine. The degradation rate of MCs by anaerobic bacteria community increased with the increasing enrichment times. After continuous enrichment, community structures of anaerobic MCs-degrading bacteria in pond sediment and shrimp intestine were stable, and the compositions of bacteria community were highly similar. The study showed that anaerobic MCs-degrading bacteria existed in anoxic environment of shrimp ponds and had anaerobic degradation effects on the elimination of MCs. The study provide a scientific reference for reducing MCs pollution in shrimp ponds through anaerobic biodegradation.
  • Co-occurrence patterns among the catch species from the purse seine fisheryin the Western and Central Pacific Ocean based on association rule mining algorithms
    FEI Jiaojiao, WU Yuntao, LUO Jiawang, TENG Yuxiu, CHEN Xianyu, ZHANG Jian, SHI Jiangao
    Journal of Dalian Fisheries University. 2025, 40(3): 463-471. https://doi.org/10.16535/j.cnki.dlhyxb.2024-250
    Abstract (1302) PDF (132) HTML (1)   Knowledge map   Save
    This study investigated the potential mechanisms by which different fishing strategies influence interspecific co-occurrence catch patterns. It used data from the 2014—2022 Western and Central Pacific Ocean purse seine fishery collected by the Shanghai Kai Chuang Pelagic Fisheries Co., Ltd. (FSC) to analyze the associative relationships between species in the FSC catch groups compared with drifting fish aggregating device (DFAD) clusters, using the Apriori association rule mining algorithm. The results indicate that there is only one association rule between the silky shark (Carcharhinus falciformis) and skipjack tuna (Katsuwonus pelamis) in the FSC group; however, the validity of this rule was not confirmed. In contrast, the associations among species in the DFAD group are significantly stronger, revealing nine high-frequency association rules. These rules involve three bycatch species： silky shark, rainbow runner (Elagatis bipinnulata), and mackerel scad (Decapterus macarellus), along with the primary species skipjack tuna and yellowfin tuna (Thunnus albacares). Notably, silky shark showed a strong association with skipjack tuna, suggesting its role as a key species in DFAD clusters, while rainbow runner frequently co-occurred with yellowfin tuna. These findings indicate that DFADs not only enhance the spatial aggregation of species but also significantly increase the co-occurrence probability between bycatch and target species. This study provides scientific support for optimizing fishing gear design, reducing bycatch, and improving regional ecosystem-based fisheries management.
  • Effects of compound Chinese herbal medicines on intestinal antioxidant capacity and immune-related gene expression of rainbow trout (Oncorhynchus mykiss)
    SUN Manqiang, HUANG Jinqiang, LI Yongjuan, WANG Qi, ZHAO Lu, GUO Zhijia, LIU Kangkang
    Journal of Dalian Fisheries University. 2025, 40(5): 809-820. https://doi.org/10.16535/j.cnki.dlhyxb.2024-284
    Abstract (1264) PDF (230) HTML (0)   Knowledge map   Save
    To investigate the effects of Chinese herbal compound medicines (CHMM) on the intestinal antioxidant capacity and expression of immune-related genes in rainbow trout (Oncorhynchus mykiss), ten Chinese herbal medicines, including Astragalus membranaceus, Angelica sinensis, Codonopsis pilosula, Ophiopogon japonicus, and Glycyrrhiza uralensis, were mixed in equal proportions and then added into the basal diet at mass ratios of 0 (control), 1%, 2%, and 3%. These diets were fed to rainbow trout with a body weight of 30.0 g± 0.5 g. The intestinal samples of fish were collected respectively after fed 7d, 21d, 35d.Additionally the samples were taken after 12d infected with infectious hematopoietic necrosis virus (IHNV).Antioxidant indicators and the expression of immune-related genes of fish were tested by using quantitative real-time PCR technology. The result showed that,compared with the control group, the total antioxidant capacity (T-AOC) and catalase (CAT), total superoxide dismutase (T-SOD), and acid phosphatase (ACP) activities in the intestines increased first and then decreased as the proportion of CHMM increased. The values peaked in the 2% group, at which point they were significantly higher than those of the control group (P<0.05). However, the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the content of malondialdehyde (MDA) first decreased and then increased, and the MDA content in the 2% group was significantly lower than that in the control group (P<0.05). After infected with IHNV, the T-AOC and activities of T-SOD, CAT, and ACP significantly increased, while the content of MDA and the activities of ALT and AST significantly decreased (P<0.05). The quantitative PCR analysis showed that before infected with IHNV, the fish in the 1% group had significantly upregulated the expression of jak1, myd88, and irf7 genes (P<0.05), while the expression levels of mx1 and mda5 were not significantly upregulated (P>0.05).In the 2% group, the expression level of immune-related gene il-8 was significantly upregulated (P<0.05), but the expression levels of il-1β, mx1, myd88, and mda5 were not significantly changed (P>0.05). After infected with IHNV, the fish in the 1% group had significantly upregulated expression levels of il-1β, mx1, mda5, lgp2, irf3, and irf7 (P<0.05). Overall, the experimental results show that the 2% addition of the CHMM could effectively improve the activity of antioxidant enzymes and regulate the expression of immune-related genes of rainbow trout. The CHMM addition also significantly enhanced the immunity and anti-IHNV ability of the fish. These findings lay the foundation for understanding the mechanisms that traditional Chinese herbal medicines enhance the natural immune response of rainbow trout to diseases and provide a helpful reference for the development and application of Chinese herbal medicine to prevent and control fish diseases in aquaculture.
  • Fighting behavior of Chinese mitten crabs (Eriocheir sinensis) cultured under different carbonate alkalinities
    OUYANG Ningyuan, CHEN Yongjin, XUE Xue, XU Dongpo
    Journal of Dalian Fisheries University. 2025, 40(5): 789-797. https://doi.org/10.16535/j.cnki.dlhyxb.2024-233
    Abstract (1253) PDF (352) HTML (0)   Knowledge map   Save
    To investigate the influence of carbonate alkalinity on fighting behavior of crustaceans and to clarify the behavioral mechanism among the same crustacean species, we took the Chinese mitten crab (Eriocheir sinensis) as the experimental species. We used the behavior research methods in a limited space, did one-on-one crab fighting experiments and attack experiments of crabs rapped, and explored the characteristics of crab fighting and attack behavior under different carbonate alkalinity stress.The results showed that the duration of crab fighting, number of fights, fight scores and attack scores of crab rapped first increasedand then decreased as carbonate alkalinities went up.Fighting and attack behavior of crabs became moderate significantly at 60 mmol/L of carbonate alkalinity.The attack number of crab nylon-rod rapped also gradually decreased. The average duration of crab fighting at a high carbonate alkalinity was generally longer than that at a low carbonate alkalinity. Additionally, the average duration of fighting and number of fights between female crabs were slightly more than those between male crabs, but the fighting score between female crabs was slightly lower than that between male crabs. The number of attacks between male crabs rapped was slightly lower than that between female crabs, while the aggressiveness score for male crabs was slightly higher than that for female crabs. However, there was no significant difference in these two indicators for male crabs fighting and female crab fighting under different carbonate alkalinity stress. The experimental results showed slightly higher values of fighting duration, average fighting duration, and attacks score during the day than those at night, while the number of fights, fighting scores, and attack frequency were slightly lower during the day than those at night. But the A0 group with no alkalinity showed the attack frequency of rapped crabs was significantly lower during the day thanthat at night. The study primarily revealed the characteristics of fighting behavior of E. sinensis under carbonate alkalinity stress. It provided scientific references for E. sinensis cultivation in saline alkaline water, protection of wild crab population, and control of ecological invasion.
  • Microsatellite analysis of genetic diversity among five cultured populations of Leiocassis longirostris
    YU Aiqing, SHI Yonghai, XU Jiabo, LIU Yongshi, JIANG Fei, YUAN Xincheng
    Journal of Dalian Fisheries University. 2025, 40(4): 618-627. https://doi.org/10.16535/j.cnki.dlhyxb.2024-268
    Abstract (1233) PDF (414) HTML (0)   Knowledge map   Save
    We investigated the genetic diversity and genetic structural differences among different cultured populations of Leiocassis longirostris to enable the development of effective scientific strategies for the selection and breeding of superior varieties. Twenty fluorescently labeled EST-SSR primers were selected to evaluate the genetics of five cultured populations of L. longirostris from Shanghai Baoshan (BS), Jiangsu Changzhou (CZ), Sichuan Meishan (MS), Guangdong Shunde (SD), and Hubei Xiantao (XT). We detected a total of 219 alleles from 20 EST-SSR primers, with an average of 10.95 alleles per primer. The average number of effective alleles (Ne), observed heterozygosities (HO), expected heterozygosities (He) and polymorphism information contents (PIC) of the five cultured populations ranged from 3.03 to 4.13, from 0.708 3 to 0.813 3, from 0.624 3 to 0.727 6, and from 0.574 0 to 0.686 5, respectively. Hardy-Weinberg Equilibrium (HWE) tests indicated that out of the 100 population locus combinations analyzed, 45% significantly deviated from the HWE (P<0.05). A population genetic differentiation analysis showed that the BS population exhibited moderate genetic differentiation (0.05<Fst<0.15) while the MS, SD, and XT populations, showed weak genetic differentiation in pairwise tests (Fst<0.05). Molecular variance analysis results indicated that the majority of the genetic variation originated from differences among individuals within the populations (95.28%), with only 4.72% of the genetic variation stemming from differences between populations. Consistent results were obtained from an Unweighted Pair-Group Method with Arithmetic Mean analysis, a Principle Component analysis, and a Bayesian Structure Clustering analysis and revealed two major groups among the five cultured populations: the BS population formed a separate group, while the CZ, MS, SD, and XT populations clustered into a second group. This study showed that five cultured populations of L. longirostris had relatively high levels of genetic diversity and exhibited varying degrees of genetic difference. In particular, the BS population showed a relatively independent genetic structure.
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Editor-in-Chief: SONG Linsheng
Deputy Editor-in-Chief:
ZHANG Guochen
LI Zhijun
LIU Ying
ZHANG Dongdong (executive)
Sponsor: Dalian Ocean University
Supervisor: Education Department of Liaoning Province
Address: No. 52,Heishijiao street, Shahekou District, Dalian, Liaoning Province, China
Postal code: 116023
Tel: 0411-84762672
E-mail：xuebao@dlou.edu.cn
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