Effect of food concentration on the production and viability of resting eggs of the rotifer Brachionus: implications for the timing of sexual reproduction

摘要

Summary1. Life-table experiments with Brachionus calyciflorus test several hypotheses related to the idea that sexual reproduction in monogonont rotifers should occur when food resources are favourable.2. The food concentration necessary for a fertilised mictic female to produce one phenotypically normal resting egg was higher than that for an amictic female to produce one daughter. At the lowest concentration of Cryptomonas erosa (1.25 x 103 cells mL-1), the lifetime fecundity of these two types of females was 0.9 and 1.4, respectively.3. The lifetime fecundity of both fertilised mictic females and amictic females increased with food concentration to 3.4 resting eggs and 15.2 daughters female-1, respectively. The approach to maximal fecundity with increasing food concentration was more rapid for fertilised mictic females, such that their lifetime fecundity relative to that of amictic females gradually decreased from 0.64 (at 1.25 x 103