Seventeen species of zooplankton representing four phyla were collected from Bute Inlet, one of the deep inlets (650 m) in British Columbia. Using lipid analysis and starvation studies, the zooplankton were divided into two categories based on whether the level of storage lipid was high or low. The polychaetaes, chaetognaths, and one of the ctenophores (Pleurobrachia pileus) were characterized by little storage lipid (neutral lipid only 7–10% of the lipid). It is assumed that these species transfer most new organic matter into new tissue rather than storage lipid. The copepods, Calanus plumchrus, Eucalanus bungi, Gaetanus columbiae, and Heterorhadus tanneri, were all characterized by high levels of storage lipid (between 53 and 90% of the lipid) and, except for Eucalanus, these consisted mainly of wax esters. The remaining zooplankters (ostracods, pteropods, euphausiids, amphipods, and decapods), except for the ctenophore, Beroe cucumis, stored primarily triglycerides. In all species examined, except B. cucumis, five fatty acids, 16:0, 16:1, 18:1, 20:5, and 22:6, accounted for over 90% of the total phospholipid fatty acid complement. Polyunsaturated C16 and C18 acids, which are common in phytoplankton, were absent or present in trace amounts in phospholipids but were abundant in the neutral lipids of herbivorous zooplankton. The wax esters of G. columbiae and B. cucumis had high levels of 16:0, 20:1, and 22:1 alcohols, whereas C. plumchrus had only 20:1 and 22:1 alcohols as major components.