| 摘要: |
| 长江禁渔后，鄱阳湖凶猛性鱼类资源恢复明显，探究其在自然环境中的食物组成对预测鄱阳湖鱼类资源发展走势具有重要意义。本研究于2022年8-11月分别在鄱阳湖5个采样点(都昌、南矶山、鄱阳、余干和进贤)使用三层流刺网采集了共计240尾的鲇、乌鳢、鳜、翘嘴鲌样品。分别使用胃含物分析法和eDNA宏条形码技术对这4种凶猛性鱼类的食物组成进行了分析。基于胃含物分析法的结果表明，四种鄱阳湖凶猛性鱼类鲇、乌鳢、鳜和翘嘴鲌的摄食率较高，空胃率低。鱼类在四种凶猛性鱼类的食物组成中占比较高，其次为虾类。鲇、乌鳢、鳜和翘嘴鲌的食物分别由5类10种、4类15种、3类11种和5类12种饵料生物组成，其中IRI%最高的饵料生物分别为鲫、鲫、?和鲤；鲫、鲤、泥鳅和日本沼虾均在四种凶猛性鱼类的肠道内容物中出现。基于eDNA宏条形码技术的结果中，饵料生物种类与胃含物分析法结果相似，分别在鲇、乌鳢、鳜和翘嘴鲌的肠道内容物中发现了7、5、6和6种饵料生物。其中相对丰度百分比最高的饵料生物分别为鲤、鲤、鲤和鲢。此外，结果中发现了发现了新的饵料生物存在，即团头鲂、似鳊、贝氏?和黑尾近红鲌四种饵料生物，前者并未在胃含物分析结果中检出。综上，长江禁渔后鄱阳湖的凶猛鱼类的食物来源充足，食性范围广泛，其中鱼类是其主要的食物来源，其次为虾类。同时，胃含物分析法与eDNA宏条形码技术的结合能够更好地探究鱼类的食物组成，是综合分析鱼类食性的有效途径。 |
| 关键词: 鄱阳湖 食性 鲇 乌鳢 鳜 翘嘴鲌 胃含物分析法 eDNA宏条形码技术 |
| DOI： |
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| Dietary analysis of ferocious fishes in Poyang Lake based on stomach content analysis and eDNA Metabarcoding technology |
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Zhao Mingguang1, Feng Guangpeng1, Wang Haihua1, Chen Jianhua2, Shen Chenchen3, Zhang Yanpin1, Zhang Haixin1, Fu Yilong1, Yao Yuan1, Xu Weikang2
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1.Jiangxi Fisheries Research Institute;2.School of Marine Science and Fisheries of Jiangsu Ocean University;3.East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences
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| Abstract: |
| After the closure of fishing in the Yangtze River, the recovery of carnivorous fish resources in Poyang Lake has been significant, and exploring their dietary composition in the natural environment is crucial for predicting the development trend of fish resources in Poyang Lake. This study collected 240 specimens of Silurus asotus, Channa argus, Siniperca chuatsi, and Culter alburnus with three-layer drift gillnet at five sampling points (Duchang, Nanjishan, Poyang, Yugan, and Jinxian) in Poyang Lake from August to November 2022. The dietary composition of four fierce fish species in Poyang Lake was analyzed using stomach content analysis and eDNA Metabarcoding technology. The results of Stomach content analysis showed that these fish species had a high feeding rate and a low empty stomach rate. Fish constituted a significant part of their diet, followed by shrimp. The diets of S. asotus, C. argus, S. chuatsi, and C. alburnus consisted of prey from 5 categories and 10 species, 4 categories and 15 species, 3 categories and 11 species, and 5 categories and 12 species, respectively, with the highest IRI% prey being Carassius auratus, C. auratus, Hemiculter leucisculus, and Cyprinus carpio, respectively. C. auratus, C. carpio, Misgurnus anguillicaudatus, and Macrobrachium nipponense were found in the intestinal contents of all four fierce fish species. The results based on eDNA metabarcoding technology show that the types of prey organisms are similar to those obtained from stomach content analysis, identifying 7, 5, 6, and 6 prey species in the gut contents of S. asotus, C. argus, S. chuatsi, and C. alburnus, respectively, with C. carpio, C. carpio, C. carpio, and Hypophthalmichthys molitrix having the highest relative abundance percentages. Additionally, eDNA metabarcoding technology revealed new prey species not detected in stomach content analysis, including Megalobrama amblycephala, Pseudobrama simoni, Hemiculter bleekeri, and Ancherythroculter nigrocauda. In summary, after the fishing ban in the Yangtze River, the predatory fish in Poyang Lake have an abundant food supply and a wide diet range, with fish being their primary food source, followed by shrimp. And the combination of stomach content analysis and eDNA metabarcoding technology allows for a more comprehensive investigation of fish diets, making it an effective approach for analyzing fish feeding habits. |
| Key words: Poyang Lake Diet Silurus asotus Channa argus Siniperca chuatsi Culter alburnus Stomach content analysis eDNA Metabarcoding |
