Comparative Studies on Population Growth of Two Brachionus calyciflorus Sibling Species

Abstract

Rotifers are the most important live food organisms for use as starter food in aquaculture. The population growth and resting egg production dynamics of Brachionus calyciflorus sibling species BNA13 from lake Baixiang and BNB3 from lake Kongque, in Xishuangbanna city, Yunnan, China at four temperatures (16, 20, 24, and 28°C) and four algal (Scenedesmus obliquus) densities (0.5, 1.0, 2.0, and 4.0 9 10 6 cells/ml) were studied. The results showed different responses with rotifer sibling species. Sibling species, temperature, algal density and their interactions significantly affected the maximum population density, population growth rate and resting egg production except that both the interactions of temperature and algal density and the interaction of sibling species and temperature as well as algal density did not significantly affect maximum population density. Regardless of the effects of temperature and algal density, maximum population density, population growth rate and resting egg production of the B. calyciflorus sibling species BNA13 were greater than those of BNB3, suggesting that B. calyciflorus sibling species BNA13 was more suitable than BNB3 for fish larviculture. The maximum population density and resting egg production of sibling species BNA13 were the highest at the combination of 20°C and 4.0 9 10 6 cells/ml algal density and 28°C and 4.0 9 10 6 cells/ml algal density, respectively, indicating that the two combinations of temperature and algal density represented the optimum conditions of mass culture and resting egg production of B. calyciflorus sibling species BNA13 for fish larviculture respectively.

Patterns of differentiation in the life history and demography of four recently described species of the Brachionus calyciflorus cryptic species complex

“…So far, information on life history divergence among species of the B. calyciflorus species complex has been scant and fragmented. While many studies have investigated the life history response of B. calyciflorus to specific ecological factors, mainly temperature and food quantity (Li, Xi, & Cheng, ; Ma, Xi, Zhang, Wen, & Xiang, ; Xiang, Xi, Zhang, Ma, & Wen, 2010c; Xiang et al., ) molecular information on the phylogenetic position of the investigated genotypes is seldom provided.…”