Analyses of fatty acids from Newfoundland copepods and sea water with remarks on the occurrence of arachidic acid

Comparisons of the total fatty acids from some North Atlantic (Newfoundland) spring copepods (mostlyTemora longicornis) and from associated sea water have been made. The animal fatty acids were similar in composition to published data for other copepods and this suggests a basic differentiation among planktonic crustacea by which species and genus fatty acid compositions may be compared. The fatty acids recovered from sea water unexpectedly showed a high proportion (∼9%) of arachidic acid, which is normally a very minor component in marine lipids of either plant or animal origin. The evidence bearing on widespread occurrence of this acid in sea water and sediments is reviewed.