Effect of periodical starvation on the life history of Brachionus plicatilis OF Muller (Rotifera): a possible strategy for population stability

To estimate the changes in the life history of the rotifer Brachionus plica tilis O.F. Muller under starvation, we carried out an individual culture an d determined the effects of periodical food deprivation on its asexual repr oductive characteristics such as lifespan, reproductive period, age at firs t egg and offspring production, and lifetime fecundity (total number of off spring produced in her lifetime). Rotifers were fed for 1-3 h daily, and we re then starved until the next day. Control animals were fed throughout the ir lifespan. Starved rotifers matured and produced their first offspring at an older age than the control animals. The periodical starvation resulted in a decrease in the lifetime fecundity to less than half that of the non-s tarved control. The reproductive period and lifespan were 2-3 times longer in the starved animals than in the control animals. The negative relationsh ip between lifespan and lifetime fecundity is interpreted as a trade-off in an alternative life-history strategy of rotifers under starved conditions. The great decrease in fecundity and extension of lifespan enables rotifers to compensate to keep the population in equilibrium. (C) 2000 Elsevier Sci ence BN. All rights reserved.