关键词: 金湖, 鱼类群落结构, 鲢, 鳙, 生长模型

Abstract:

In order to provide basic data for biological control of water quality,to improve of fishery potential and economic benefits,we characterized the fish community and measured growth rates of H.molitrix and A.nobilis in Jinhu Reservoir.Making use of mixed gill nets,a systematic fishery investigation was conducted in Janurary,April,July,and October of 2022,respectively.A total of 32 fish species were collected,belonging to 26 genera,8 families and 3 orders.Cypriniformes was the largest order,which accounted for 75.0%.The ecological type analysis revealed that the community was dominated by carnivorous and omnivorous fish.Four dominant fish species were identified based on the index of relative importance,which were H.molitrix,A.nobilis,Xenocypris microlepis and Culter dabryi dabryi.The growth equation of body length and body mass for H.molitrix,they were L_t=74.52×[1-e^{-0.26(t+0.35)}];W_t=6 925.48×[1-e^{-0.26(t+0.35)}]^{2.906 9},respectively,and for A.nobilis were L_t= 68.35×[1-e^{-0.19(t+0.82)}];W_t = 5 669.32×[1-e^{-0.19(t+0.82)}]^{2.973 0},respectively.The highest body mass growth rate for H.molitrix occurred during the age of 1-4,and then decreased gradually,with the growth inflexion points at the age of 3.75.And infection point for A.nobilis was 4.91.As a result,the most appropriate catching age were 4-year-old for H.molitrix and 5-year-old for A.nobilis in order to get the best effect on algal bloom control and economic benefit.The results provided important scientific evidence for rational utilization of H.molitrix and A.nobilis resources and ecological environment restoration in Jinhu Reservoir of Taining,Fujian Province,China.

Key words: Jinhu Reservoir, fish community, Hypophthalmichthys molitrix, Aristichthys nobilis, growth model