Carbon, Nitrogen, And Phosphorus Stoichiometry of Three Freshwater Cultured Fishes in Growth Stage

Özet

Fish is important in the nutrient cycling of ecosystem, but little is known about how nutrients of cultured fish vary withgrowth. Whole body samples of three freshwater cultured fish species, grass carp (Ctenopharyngodon idella), common carp(Cyprinus carpio) and tilapia (Oreochromis niloticus) were collected from May to October in 2015. The contents of carbon(C), nitrogen (N) and phosphorus (P) were measured, and their ratios were analyzed, aiming to characterize the bodystoichiometry of these fish species during farming season. The main results are as follows: the concentrations of C, N, P andtheir ratios varied across species, while the P content in O. niloticus was significantly higher than that in C. idella and C.carpio (P < 0.05). The correlation analysis showed that body stoichiometry of the three fish species varied with size andgrowth significantly during the farming season. The relationship between growth rate and P content showed varied andcomplex relationship. Results indicated that the three fish species in aquaculture ponds did not follow strict homeostasis andthe growth rate hypothesis, and bone rather than RNA was the dominant P pool. Body morphology, scale type, and foodsource were the main causes of interspecific differences.