Abstract
Lipid content and composition of some dominant copepods inhabiting the Oyashio waters were analyzed by the thin layer chromatography flame ionization detection (TLC/FID) method. Copepod samples were collected during the RV Shoyo-maru cruise from September 18 to October 15 in 1988. A new three-step development: the first in hexane and diethyl ether (66 : 4, v/v), the second in hexane, diethyl ether and formic-acid (55 : 15 : 0.5) and the last in hexane and benzene (1 : 1), single scan method by TLC/FID was found to be useful for separation and analysis of lipids in boreal copepods. As a result, the eight species of calanoid copepods analyzed in this study could be divided into two groups according to their lipid class proportions. One group consisted of copepods containing many wax esters and includes Neocalanus flemingeri, N. cristatus, Pseudocalanus minutus, Metridia pacifica and M. okhotensis. The other group containing many triglycerides includes Eucalanus bungii, Pleuromamma abdominalis and Acartia omorii. I have deduced that copepods storing wax esters could have long periods of dormancy in winter and consume lipids mainly for reproduction, while copepods storing triglycerides could overwinter without a period of dormancy and be opportunistic feeders.
