Turkish Journal of Fisheries and Aquatic Sciences
2018, Vol 18, Num, 2 (Pages: 239-245)
Carbon, Nitrogen, And Phosphorus Stoichiometry of Three Freshwater Cultured Fishes in Growth Stage
2 Guangxi key laboratory of Marine Biotechnology, Guangxi Institute of Oceanology, Beihai 536000, P.R. China
3 Shandong Freshwater Fisheries Research Institute, Jinan 250000, P.R. China DOI : 10.4194/1303-2712-v18_2_03 Viewed : 4099 - Downloaded : 3069 Fish is important in the nutrient cycling of ecosystem, but little is known about how nutrients of cultured fish vary with growth. 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 body stoichiometry of these fish species during farming season. The main results are as follows: the concentrations of C, N, P and their 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 and growth significantly during the farming season. The relationship between growth rate and P content showed varied and complex relationship. Results indicated that the three fish species in aquaculture ponds did not follow strict homeostasis and the growth rate hypothesis, and bone rather than RNA was the dominant P pool. Body morphology, scale type, and food source were the main causes of interspecific differences. Keywords : Cultured fishes, growth stage, ecological stoichiometry, homeostasis, growth rate hypothesis