Ref ID : 126
William N. Bennett and Martin E. Boraas; A demographic profile of the fastest growing metazoan: a strain of Brachionus calyciflorus (Rotifera). OIKOS 55:365-369, 1989
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Evidence shows that trade-offs between growth, reproduction and maintenance tend to maximize the maximum specific growth rate, u(max), of a population for a given environment. We tested this hypothesis with two rotifer (Brachionus calyciflorus Pallas) populations which differed with respect to their u(max). Through measurement of various demographic variables, we found that the population which had a higher u(max) also possessed the following characteristics: 1) higher fecundity in younger age classes, 2) decreased life span, 3) decrease in egg production times, 4) a loss of sexuality, 5) a 24% decrease in adult body size and 6) a 71% decrease in egg volume. The results support the hypothesis of a trade-off between reproduction and growth maintenance, whereby, production of energy stores is negatively correlated with increased u(max). The lower u(max) observed in field-collected populations may result from the need to produce energy stores for patchy and variable environmental conditions.