ECOLOGICAL STOICHIOMETRY CHARACTERISTICS OF THREE DOMINANT FISH SPECIES IN TYPICAL PLAIN LAKES IN HUBEI PROVINCE, CHINA

In order to explore the ecological stoichiometry characteristics of three dominant fish species in typical plain lakes in Hubei Province, this study systematically collected samples of three dominant fish species (crucian carp, Toxabramis swinhonis and Hemiculter leucisculus) from eight typical plain lakes in Hubei Province, China, and analyzed their carbon (C), nitrogen (N), and phosphorus (P) composition characteristics and correlations with environmental factors. The results showed that the content of C, N, and P in the three fishe species ranged from 29.2%—50.8%, 6.91%—13.7%, and 1.75%—6.79%, with C﹕N, C﹕P, and N﹕P were 11.38—66.35, 3.64—5.91, and 2.27—16.96, respectively, among which P content exhibited the highest coefficient of variation. The content and ratio of C, N, and P in the three fishe species showed significant interspecific differences (P<0.05), and the difference in P content was most obvious. Nonparametric tests showed that certain elemental contents and ratios differed significantly among lakes with varying nutrient levels (P<0.05), and correlated significantly with the trophic status index (P<0.05). In addition, as the lake nutrient levels increased, three fish species tended to to accumulate more fat. Overall, under the change of living environment, the ecological stoichiometric characteristics of three fish species did not maintain strict dynamic balance but were regulated by the nutrient status of the lake.