The feed of the whitefish (Coregonus lavaretus) in the Strbske pleso mountain lake [Slovak Republic]
1990
Nagy, S. (Ustav Rybarstva a Hydrobiologie, Bratislava (CSFR))
Fifty-seven specimens of the whitefish, captured in spring, summer and autumn, were investigated for the qualitative and quantitative composition of the food of this fish species. Its food spectrum of the whitefish includes 25 items. The food importance index values were the highest in the water fleas (Cladocera) I = 149.10 and in the pupae of the chironomids I = 110.5. As to the seasonal variation, the chironomid pupae prevail in spring (I = 233.44) and the water fleas prevail in summer and autumn (I = 246.03 and I = 244.38, respectively). The index of filling amounted to 0.155 per cent in spring, 0.182 per cent in summer and 0.107 per cent in autumn. The value of the trophic index is 3.00, which testifies to the prevalence of invertebrates in the food spectrum of the fish. This corresponds with the relative length to the alimentary tract which is equal to 79.8 per cent of body length. It follows from the data that the Coregonus lavaretus living in the Strbske pleso takes its food mainly in the pelagial zone and that its food spectrum largely consists of the zooplankton and, during some periods, of the emergent constituents of the zoobenthos.
显示更多 [+] 显示较少 [-]