Starvation and the size structure of zooplankton communities*

Abstract

Summary The survival time of zooplankton under conditions of total starvation is expressed as a function of weight‐specific respiration rate and the fraction of initial (pre‐starvation) body weight which may be lost prior to death. Data from the literature on these two components of survival time are used to formulate a general expression of survivorship of zooplankton at 20°C as a function of body weight: t=2·95 w 0·25 , where t is in days and w is μg dry weight. Survival time data from the literature on 25 marine and freshwater species are compared to this prediction as are new data on Daphnia pulex Leydig, D. magna Straus and Simocephalus serrulatus (Koch). The effects of age‐specific (non‐starvation) mortality are considered; in particular, older individuals of each of these species survive for shorter periods of time than predicted and an interaction between age‐specific and starvation‐induced mortality is proposed. The effects of total and partial starvation on the size structure of zooplankton communities are discussed.