Abstract:为了分析草鱼(Ctenopharyngodon idella)选育群体不同世代的遗传变异和遗传结构, 本研究利用了已建立的一套标准微卫星标记对草鱼长江选育群体 F0、F3、F4 进行了遗传变异的评估, 并与黑龙江选育群体和珠江选育群体进行了遗传变异的比较分析。实验结果表明长江选育群体的各世代均具有高度的遗传多样性(PIC＞0.05), 且长江选育群体的遗传多样性相对于黑龙江和珠江选育群体的遗传多样性水平更高(P＜0.05)。遗传分化指数(Fst)分析结果表明, 长江选育群体 F0、F3、F4 之间遗传分化的水平较低(0

Abstract:为开发中华绒螯蟹(Eriocheir sinensis)新种质并阐述其品质特征, 本研究以北方寒区 2 龄雄性成熟中华绒螯蟹(简称 2 龄蟹)为对照, 探究 3 龄雄性成熟中华绒螯蟹(简称 3 龄蟹)的可食率、色泽、常规营养品质、脂肪酸、游离氨基酸和矿物质元素差异, 为 3 龄蟹新种质开发和利用提供重要的判断依据。结果表明; 9 月 15 日 2 龄蟹肝胰腺指数(HSI)极显著高于 3 龄蟹(P＜0.01), 而出肉率(MY)则显著低于 3 龄蟹(P＜0.05)。2 龄蟹与 3 龄蟹相比, 头胸甲和肝胰腺湿样 L* , 头胸甲和肝胰腺干样 a* 存在显著性差异(P＜0.05)。2 龄蟹肝胰腺中粗脂肪含量显著高于 3 龄蟹 (P＜0.05), 而性腺系统和肌肉中粗蛋白含量则高于 3 龄蟹。就脂肪酸而言, 2 龄蟹肝胰腺、性腺系统和肌肉中 DHA 和 DHA/EPA 含量均高于 3 龄蟹, 而 ARA 则低于 3 龄蟹。肌肉中脂肪酸显著性差异项(5 项)明显高于肝胰腺(1 项) 和性腺系统(1 项)。就游离氨基酸而言, 2 龄蟹肝胰腺、性腺系统和肌肉中总必需氨基酸(ΣEFAA)、总游离氨基酸 (ΣFAA)均高于 3 龄蟹。性腺系统中显著性差异项(6 项)明显高于肝胰腺(0 项)和肌肉(2 项)。2 龄蟹肝胰腺和性腺系统中谷氨酸(Glu)、总鲜味氨基酸(ΣTUV)高于 3 龄蟹, 而肌肉中则低于 3 龄蟹。就矿物质元素而言, 2 龄蟹 3 种可食组织中 Na、K、Ca、Mg 和 Cu 元素含量均低于 3 龄蟹。肝胰腺中矿物质元素显著性差异项(5 项)明显高于性腺系统 (1 项)和肌肉(2 项)。综上所述, 2 龄蟹大部分常规营养成分、脂肪酸、游离氨基酸指标均优于 3 龄蟹, 但可食率参数、大部分矿物质元素含量则明显低于 3 龄蟹。整体来看, 2 龄和 3 龄雄蟹各有优势, 均具有较高的营养价值。

Abstract:为探究垂盆草提取物对吉富罗非鱼(Oreochromis niloticus)脂肪性肝病的干预作用及机制, 实验配制对照组 (0%大豆油, 0%垂盆草提取物)、高脂组(4%大豆油, 0%垂盆草提取物)和垂盆草干预组(4%大豆油, 0.12%垂盆草提取物) 3 种等氮饲料, 饲养初始体重为(11.63±0.66) g 的吉富罗非鱼 8 周后, 取吉富罗非鱼血清和肝脏, 采用非靶向代谢组学检测方法, 并结合肝脏组织透射电镜观察、血清生化指标结果进行分析。结果显示, 高脂组体重、增重率 (WGR)和特定生长率(SGR)显著低于对照组与垂盆草干预组(P＜0.05), 肝体比(HSI)、饲料系数(FRC)显著高于对照组与垂盆草干预组(P＜0.05)。透射电镜观察发现高脂组与对照组相比, 肝组织细胞超微结构异常, 垂盆草干预组与高脂组对比有所改善。血清生化指标显示垂盆草干预组较高脂组谷丙转氨酶(ALT)、谷草转氨酶(AST)、甘油三酯 (TG)、总胆固醇(T-CHO)、低密度脂蛋白胆固醇(LDL-C)、肿瘤坏死因子 α (TNF-α)和白细胞介素 8 (IL-8)水平显著降低(P＜0.05), 高密度脂蛋白胆固醇(HDL-C)、超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)和白细胞介素 10 (IL-10) 水平显著升高(P＜0.05)。肝脏代谢组学检测结果表明, 与对照组相比, 高脂组有 27 个差异代谢产物(DM), 富集到 19 条通路, 主要代谢通路为糖酵解/糖异生、丙酮酸代谢、β-丙氨酸代谢; 与高脂组相比, 垂盆草干预组有 23 个差异代谢产物, 富集到 9 条代谢途径, 主要代谢通路为 β-丙氨酸代谢和亚油酸代谢。上述结果表明, 垂盆草提取物对于干预吉富罗非鱼因高脂饮食引起的脂肪性肝病有积极作用, 其作用通路与 β-丙氨酸代谢、亚油酸代谢相关。

Abstract:Six isonitrogenic and isoenergy diets were designed to investigate the effects of tea tree essential oil and astaxanthin on growth performance, antioxidant capacity, and immune-related gene expression of Proambarus clarkii: basal diet (CT), astaxanthin 50 mg/kg (AS50), 50 mg/kg astaxanthin and 50 mg/kg tea tree oil (AS50+AST50), 50 mg/kg astaxanthin and 100 mg/kg tea tree oil (AS50+AST100), 50 mg/kg astaxanthin and 200 mg/kg tea tree oil (AS50+AST200), and 50 mg/kg astaxanthin and 400 mg/kg tea tree oil (AS50+AST400). An 8-week culture experiment was conducted. After astaxanthin was added, the feed conversion ratio of AS50 was significantly decreased (P＜0.05), the final average weight, weight gain rate, and specific growth rate with the increased trend showed no significant differences with the CT group (P ＞ 0.05), and the total antioxidant capacity (T-AOC) in hemolymph and intestinal tissue was significantly increased compared with the CT group (P＜0.05). The content of malondialdehyde (MDA) in hemolymph and intestinal tissue was significantly decreased (P＜0.05). The expression of the Crustin, Astacidin, CuZnSOD, and HSP70 genes was significantly increased compared with the CT group (P＜0.05). After tea tree essential oil and astaxanthin were added, the final body weight, weight gain rate, specific growth rate, and T-AOC in AS50+AST100 were significantly higher than in AS50 and CT groups (P＜0.05), and the intestine MDA content was significantly lower (P＜0.05). The expression levels of the Crustin and Astacidin genes in intestinal tissues increased with the increase of tea tree essential oil content and was significantly lower for the combination group of AS50 and AST50 than in the other groups (P＜0.05). The expression level of CuZnSOD was first increased and then decreased with the increase of tea tree oil concentration and was significantly higher in the AS50+AST50 and AS50+AST100 groups than in the other groups (P＜0.05). The expression of HSP70 were significantly higher than those in the CT group (P＜0.05). The results showed that adding a combination of 50 mg/kg astaxanthin and 100 mg/kg tea tree oil to the diet could improve antioxidant and immune capacity and promote the growth of Procambarus clarkii.

Abstract:Astragalus polysaccharide (APS) is a soluble polysaccharide extracted from the root of Astragalus membranaceus that exerts many biological effects such as antibacterial and antioxidant effects, enhancing immunity and improving growth performance. To evaluate the potential effects of APS in Qihe crucian carp (Carassius auratus) as an immunopotentiator, the growth performance, viscera somatic index, antioxidant capability, and disease resistance of Qihe crucian carp administrated with APS were investigated in the present study. The experimental fish were randomly divided into four groups (30 fish per group with 3 repeats) and a 42 d growth trial was conducted. For the test groups (APS-1, APS-2, APS-3), fish were fed with basal diet supplemented with 500, 1,000, and 1,500 mg/kg APS, respectively. Meanwhile, the fish in the control group (CT) were fed with basal diet. The results show that dietary APS can increase the body weight growth rate (WGR) significantly (P＜0.05). The WGR in APS-3 group was highest and significantly higher than in the APS-1 or APS-2 group (P＜0.05). The specific growth rate of Qihe crucian carp was higher in the three test groups than in the control, but there was no significant difference among the APS-1, APS-2, and APS-3 groups, and there was no significant difference between the test groups and the control in feed conversion ratio. Previous studies suggested that APS could increase the viscera somatic index and promote the development and maturity of immune organs, thereby enhancing the immunity of organisms. However, the present study observed no significant difference in the kidney index or spleen index, and the liver index was significantly greater only in the Qihe crucian carp with the APS additive of 1000 mg/kg (APS-2 group) than in the control. This result indicates that APS additive of 1000 mg/kg could promote the development of the liver in Qihe crucian carp. Moreover, the enzymic activities of superoxide dismutase, catalase, and glutathione peroxidase (GPx) in the liver of fish in three test groups were higher than in the control. The highest values of SOD and GPx activities were presented in the APS-2 group, and were 46.6 U/mL and 41.8 U/mL, respectively. However, the activity of CAT in APS-2 group was the lowest among the three test groups, although it was significantly higher than in the control (P＜0.05). Additionally, the content of malondialdehyde (MDA) in the liver of Qihe crucian carp was significantly lower in three test groups than that in the control (P＜0.05), and the MDA content in APS-2 group was the lowest at 8.2 nmol/L. Therefore, APS additive in diets can enhance the antioxidant capacity of Qihe crucian carp, remove excessive reactive oxygen species, thus reduce oxidative damage, and decrease the content of MDA, which is the end product of lipid peroxidation. After challenge with Aeromonas hydrophila, the survival rate of Qihe crucian carp fed with APS additive was higher than that of the control. The survival rate of the fish fed with APS additive of 1,000 mg/kg was highest among three test groups at 75% after 96 h post infection. In conclusion, APS additive could improve the disease resistance of Qihe crucian carp against bacterial infection by promoting growth and increasing the antioxidant capability. Based on the comprehensive analyses of the results of this study, the appropriate dose of APS additive was 1000 mg/kg in feed of Qihe crucian cap, which could effectively prevent and control the fish diseases caused by A. hydrophila in aquaculture.

Abstract:With the development of industries, human activities, particularly the burning of fossil fuels and deforestation, have worsened the natural greenhouse effect and aggravated the degree of global warming. It is estimated that the global average temperature will increase by 1–4 ℃ by the end of the century due to the continuous growth in CO2 emissions, which will simultaneously lead to inevitable increases in water temperatures. Rainbow trout (Oncorhynchus mykiss) is a commercially important cold-water fish. Due to its high dependence on ambient water temperature, temperature increase can adversely affect its growth and reproduction capacity and ultimately its health, even leading to death. Therefore, it is of great significance to understand the molecular mechanism of rainbow trout in response to heat stress. Metabolomics is a technology to analyze the disturbance of metabolic pathways in an organism by detecting the changes of endogenous metabolites after stimulation or disturbance. In combination with ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), it enables us to identify the holistic variable metabolites and related metabolic pathways in a living system by measuring the low-molecular-weight metabolites. In this study, heat stress experiments at 20 ℃ (T20 group) and 24 ℃ (T24 group) were carried out, taking the liver as the targeted organ, to investigate the metabolic response mechanism of rainbow trout under heat stress at the cellular level. UPLC-QTOF-MS metabolomics was used to explore the changes of endogenous metabolites in rainbow trout liver and find the differential metabolites and related metabolic pathways. Overall, 65 differential metabolites were screened in the T20 group, and were significantly enriched in 17 metabolomic pathways, including linoleic acid, galactose, α-linolenic acid, glycerophospholipid, purine, sphingolipid, and glutathione metabolisms. Meanwhile, 80 differential metabolites were screened in the T24 group, and were mainly enriched in 15 metabolomic pathways, including linoleic acid, retinol, glycerophospholipid, sphingolipid, α-linolenic acid, glutathione, and glyceride metabolisms. Among them, lipid metabolism was most significantly affected, followed by amino acid metabolism. In conclusion, heat stress induced oxidative stress in rainbow trout liver, causing activation of the glutathione metabolic pathways in a short period to accelerate the scavenging of reactive oxygen species. However, continuous heat stress damages the homeostasis of lipid metabolism, causing the reduction of metabolites such as DHA and α-linolenic acid that maintain the normal function of cells, resulting in an imbalance of the body’s immune and antioxidant systems, and further causing hepatocyte injury. This study provides insights for follow-up studies regarding the heat stress regulation mechanism of specific metabolic pathways, and a solid theoretical basis for the multi-perspective exploration of the heat resistance mechanism of rainbow trout.

Abstract:The goby is a key link in the food chain at the bottom of the ocean and plays an important role in the material circulation and energy flow of the ecosystem. Due to the large variety, extensive distribution, and small size of the goby, as well as different degrees of degradation and specialization in morphology, it presents great challenges to morphological classification and identification. In this study, 73 adult and juvenile goby samples from the Yellow Sea and Bohai Sea were identified by morphology and DNA barcoding. According to the morphological classification, 12 species of 9 genera were identified, while 13 species were identified belonging to 10 genera of family Gobiidae. Thus, in the case of insufficient experience in morphological identification or unclear morphological characteristics of juvenile fish, DNA barcoding can effectively identify species. At the same time, the list of recorded species of family Gobiidae in the Bohai Sea and Yellow Sea of China was systematically sorted out, with a total of 47 species of 29 genera. According to the recorded species list, the DNA barcodes of 29 species of 18 genera belonging to the family Gobiidae were screened and downloaded from the BOLD and NCBI databases. Combined with the 13 species of 10 genera of gobies identified in this study, a phylogenetic tree of 42 species of 26 genera was constructed, covering 89.36% of the recorded species of gobies in the Bohai Sea and Yellow Sea of China. The DNA barcode classification system of gobies was established by confirming and revising the molecular phylogenetic relationship and morphological classification status of gobies. The results of this study demonstrate the recognition efficiency of DNA barcoding in the classification of the gobies, make up for the shortcomings and limitations of traditional morphological identification methods, enrich the goby DNA barcode database, improve the goby DNA barcoding classification system, and provide a scientific basis for research on the conservation biology, evolutionary biology, and biogeography of goby fish.

Abstract:In order to rationally utilize Scomber japonicus resources and determine their replenishment law, the relationship between age, egg size, and fecundity of Scomber japonicus was studied. Reproductive population samples of Scomber japonicus collected in the central East China Sea in March or April 2021 were used. The results showed that the reproductive population of female Scomber japonicas consisted of 1+ –5+ years old, and the dominant age of 1+ and 2+ made up 68.54%. According to logistic equation fitting, the fork length of 50% sexual maturity was 256.98 mm. Independent samples T-test results showed that there was an extremely significant positive correlation between gonad development and egg size (P＜0.001). There was an extremely significant difference in egg size between the elder age group (3+ –5+ years old) and the younger age group (1+ –2+ years old; P＜0.001). The average absolute fecundity of Scomber japonicas was (358202.06±185914.39) grain/ind; the average relative fecundity in fork length was (1101.70±492.21) grain/mm; and the average relative fecundity in body weight was (881.13±311.46) grain/g. The absolute fecundity and relative fecundity in fork length increased with age, showing extremely significant positive correlations (P＜0.001). There was a significant positive correlation between relative fertility in body weight and age (P=0.017＜0.05). Regression analysis showed that the relationship between the three fertility indices and age was a power function. The absolute fertility contribution rate decreased with the increase of age, and with increasing age, the annual increase of absolute fecundity decreased continuously and then rebounded slightly at 5+ years old. Although elder Scomber japonicus produced higher egg quality and had higher fecundity, due to the small number of elder individuals, the contribution rate of absolute fecundity is smaller than that of younger fish. In formulating the management and protection measures of Scomber japonicus resources, the protection of elder Scomber japonicus should receive special attention.

Abstract:The waters of the Wanshan Islands are one of the traditional fishing grounds in China, but there is currently a lack of in-depth understanding of its fishery resources, particularly the reef fishery resources. Gillnetting and trawl surveys were conducted in the Wanshan Islands reef waters from March to April 2021, and the community structure, dominant species quantitative distribution, and diversity of fishery resources were analyzed. We captured 220 fishery species; 187 species were collected through gillnets and 52 species were collected through bottom trawl nets, affiliated with 16 orders, 72 families, and 137 genera, of which 176 species of fish and 38 species of crustaceans accounted for 80.0% and 17.3% of the total number of species, respectively. The index of relative importance (IRI) showed that the dominant species were Halichoeres nigrescens and Siganus canaliculatus in drift-net fishing and Trachurus japonicus, Leiognathus brevirostris, Thryssa kammalensis in trawl fishing, whose IRIs were higher than 1,000. The Shanon-Wiener diversity index (H′), Pielou evenness index (J′) value, and Margalef richness index (D) in gill net fishing were 2.50, 0.77, and 5.85, and in trawl fishing were 1.35, 0.54, and 2.52, respectively. The community characteristics of fishery resources have varying degrees of positive correlation with water temperature and silicate concentration. In general, the number and diversity of fishery resources found in the trammel net survey of Wanshan Islands is significantly higher than that of bottom trawl. The composition of fishery resources between the two survey methods is also quite different. Wanshan Islands are rich in rock fishery resources. However, there are fewer reef fishery resources with higher economic value.

Abstract:As the main source water supply of Xi’an city, the aquatic environment of the Heihe River directly affects the stability and sustainable development of the city and its surrounding area. To analyze the fish assemblage characteristics and historical change of the Heihe River and reveal the effect of ecologic environment change on fish assemblages, a field investigation of fish assemblage was carried out in January, May, July. and November of 2018–2019. A total of 7020 individuals from 17 species were collected, belonging to 16 genera, 5 families, and 3 orders. Cypriniformes were dominant, accounting for 82.35% of the total species. Regarding ecological guilds, fish egg sticky, omnivorous, and demersal species dominated the Heihe River, accounting for 76.47%, 64.71%, and 64.71% of the total species, respectively. Dominant species were Phoxinus lagowskii (IRI=0.5559) and Pseudorasbora parva (IRI=0.1019). The number of species (S) ranged from 12 to 17, the Shannon-Wiener diversity index (H′) ranged from 1.55 to 1.88, the Pielou evenness index (J) ranged from 0.56 to 0.66, and the Margalef species richness index (D) ranged from 1.54 to 2.15. Meanwhile, the fish biodiversity index reached its highest value in summer. Through cluster analysis and anon-metric multidimensional scaling analysis, it was shown that the fish community in Heihe River could be divided into three groups, I–III. Of these, Group I was composed entirely of fish in the Jinpen Reservoir and Groups II and III comprised fish in the canyon environment. The k-dominance curves of abundance were above either of the biomass curves, and the W-statistic values were between ?0.146 and ?0.181 in four seasons. In addition, compared with the historical data, the similarity index between 2010s and 1980s was moderately dissimilar (0.46). The results suggests that the community structure of fish species in the Heihe River, Qinling, has changed significantly. Artificial drainage system construction and habitat destruction are potential underlying reasons for the observed shifts in the fish assemblages.

Abstract:Since the end of the 20th century, giant jellyfish blooms have occurred on a nearly annual basis around the globe, with disastrous effects on the ecology of marine systems, fishery resources, coastal industries, and coastal tourism. Researchers, both domestically and abroad, have thoroughly investigated this phenomenon using nets, visual observations, underwater cameras, acoustic technology, aerial imagery, and other means to elucidate the underlying mechanisms of giant jellyfish blooms. In recent years, acoustic technology has been used to investigate the stock and behavior of giant jellyfish globally. These technologies have demonstrated favorable monitoring capabilities and the potential for their application in both resource assessment and the kinematics of the giant jellyfish. To determine the effect of Dual-Frequency Identification Sonar (DIDSON) on giant jellyfish Nemopilema nomurai monitoring in Liaodong Bay, we used DIDSON to determine quantitatively the abundance and distribution of giant jellyfish N. nomurai with individual medusae of 16–81 cm (33.01 cm±13.17 cm in July and 57.03 cm±13.44 cm in August) bell diameter in inshore waters of Liaodong Bay in July and Augus, 2017, and jellyfish anchor flow net samples were conducted simultaneously to verify DIDSON observations in the monitoring of large jellyfish. The survey results showed that DIDSON observation images can directly display the number of jellyfish and their positions in the water layer. The abundance of N. nomurai estimated by the DIDSON was 6.13 ind/(1000 m3 ), 6.71 ind/(1000 m3 ), 7.93 ind/(1000 m3 ) with mean (6.92±0.75) ind/(1000 m3 ) in July, and 1.41 ind/(1000 m3 ), 1.23 ind/(1000 m3 ), 0.55 ind/(1000 m3 ) with mean (1.07±0.37) ind/(1000 m3 ) in August. The overall average abundance of jellyfish estimated by DIDSON in July and August was 4.89 times and 3.95 times higher than that estimated by net, respectively. DIDSON images showed that N. nomurai mainly inhabited the upper and middle waters (1.1–10 m), with fewer in the bottom layer. Compared with the traditional network survey, DIDSON can more accurately observe the abundance of jellyfish in the survey area and their vertical distribution. The results suggest that it is effective to monitor the giant jellyfish using DIDSON in shallow water. The results showed that DIDSON observation can expand the monitoring content of large jellyfish, affording great advantages in the observation of its behavior. By extending the DIDSON navigation observation time and expanding its detection range, and in combination with traditional nets, the abundance of large jellyfish can be monitored more accurately.

Abstract:随着渔业资源评估理论、数理统计方法和计算机技术的进步, 资源评估模型朝着多样化和复杂化不断发展, 其中种群模拟技术是检测模型适用性和局限性的重要手段。该技术由种群仿真理念发展而来, 通过模拟“真实”种群的方式, 对资源评估结果和管理策略进行有效的评价和预测, 并凭借可结合海洋环境因子、鱼类洄游空间分布以及多鱼种渔业进行资源评估的特性, 已成为开发新资源的重要评估方法之一。为此, 本文对种群模拟的结构和发展过程进行了回顾, 对该技术的核心组成部分操作模型和常见的四类误差(过程误差、观测误差、模型结构误差和管理误差)展开分类讨论。此外, 本文还结合近年来迅速发展的数据缺乏和数据适中模型的特点, 根据实际应用案例对种群模拟的作用和使用前景进行梳理, 并就种群模拟技术发展中存在的主要问题和潜在解决办法提出分析和建议。