On the Nutrition and Metabolism of Zooplankton XIV. Utilization of Lipid byCalanus HelgolandicusDuring Maturation and Reproduction

Abstract

The abundance of calanoid copepods in marine plankton and their importance as food for certain fishes has prompted numerous studies of their biology, including several concerned with fecundity (Marshall & Orr, 1952; Mullin & Brooks, 1967; Paffenhöfer, 1970). These studies, however, have all involved animals maintained on various diets in the laboratory: data for egg-production byCalanusunder natural conditions in the sea are still needed.To ensure the survival of the young of many animal species to the stage of independent feeding, biochemical energy in the form of lipid is stored within the egg. During a recent survey ofCalanus helgolandicus(Claus) from the English Channel the level of lipid, mainly in the form of wax esters, in Stage V copepodids was found to be substantially greater than that in female adult stages (Gattenet al.1979). The difference was particularly noticeable during spring periods when egg-laying was in progress. This observation indicates a major role for wax esters during the reproduction ofCalanus.The present study seeks to establish the fate of the lipid reserves in Stage V and female adultCalanuswith particular emphasis on the extent to which the size of such reserves can be used as an index of the fecundity of this copepod.