WAX ESTERS IN TROPICAL ZOOPLANKTON AND NEKTON AND THE GEOGRAPHICAL DISTRIBUTION OF WAX ESTERS IN MARINE COPEPODS1

Abstract

Analyses of zooplankton and nekton from the central South Pacific showed that surface and epipelagic zooplankton had small amounts of neutral lipids, mainly triglycerides, while deep‐water tropical copepods had wax esters as the major lipid type, presumed to function as a reserve storage.The total lipid content and wax esters of tropical copepods captured at about 500 m were significantly lower than those of species from high latitudes. The median percentage of wax esters increased progressively from tropical to polar latitudes in nine species of Calanus and five or six species of Euchaeta. Deep‐living tropical copepods had the same median percentage of wax esters as mesopelagic and bathy pelagic copepods from a subtropical station.Caridean and penaeidean decapods and euphausiids showed less than 5% wax esters. Gnathophausia, a mesopelagic mysid, stored wax esters (32% of the lipid). A deep‐water chaetognath (Eukrohnia sp. ?) and a mesopolagic cranchiid squid had over 25% wax esters. Fish species not previously analyzed containing more than 10% wax esters included three myctophids and members of the Astronesthidae, Cheilodipteridae, Gonostomatidae, Paralepididae, Scopelosauridae, and Sternoptychidae.