Characteristics of Fish Community Structure in Qianxia Lake

CHEN Huan; LIAN Qingping; MENG Zhou; GUO Aihuan; SHENG Pengcheng; CHEN Guangmei; YUAN Julin

doi:10.15933/j.cnki.1004-3268.2025.10.015

Abstract：To investigate the characteristics of fish community structure in Qianxia Lake,a two-year survey was conducted from 2022 to 2023,with sampling performed once in March,July,October,and December of each year,resulting in a total of eight sampling events.The results showed that a total of 40 fish species were collected and identified,belonging to 3 orders,9 families,and 31 genera.Among them,Cypriniformes accounted for the highest proportion(30 species,75％).Ecological type analysis indicated that sedentary(92.50％),omnivorous(50％),and bottom-dwelling fish(42.5％)were the main ecological groups.Community structure analysis identified six dominant species:Hemiculter leucisculus,Sinibrama macrops,Xenocypris microlepis,Coptodon zillii,Hypophthalmichthys nobilis and Culter alburnus.The results of Margalef species richness index and Shannon-Wiener diversity index in biodiversity indexes showed that 2023 was higher than 2022.The results of catch per unit fishing effort showed that the average catch number per unit fishing effort and catch biomass per unit fishing effort in 2023 were higher than those in 2022,and the peak of catch number per unit fishing effort and catch biomass per unit fishing effort appeared in July 2023,with values of 8.32 ind/(m2·d)and 1 131.88 g/(m2·d),respectively.The abundance-biomass comparison curve(W2=0.037)indicated that the water body was in a moderately disturbed state.In summary,the construction of the Qianxia Lake Reservoir has changed the original fish resources situation.At the same time,the increase in the number of alien species and the risk of fish miniaturization may have a negative impact on the indigenous fish in the water area.