CHANGES IN LIPID-COMPOSITION OF THE ANTARCTIC KRILL EUPHAUSIA-SUPERBAIN THE INDIAN SECTOR OF THE ANTARCTIC-OCEAN - INFLUENCE OF GEOGRAPHICAL LOCATION, SEXUAL MATURITY STAGE AND DISTRIBUTION AMONG ORGANS

Lipid content and lipid class composition of Euphausia superba were st udied at different levels for populations and individuals sampled in t he Indian sector of the Antarctic Ocean. Strong site-to-site variabili ty was recorded which could only partially be related to sex or develo pment stage differences. Three groups of stations could be differentia ted. Northern stations were characterized by 'high lipid-high triglyce ride' content, western and eastern locations by 'high lipid-high phosp hatidyl choline' content and southern areas by 'low lipid-high phospha tidyl ethanolamine/glycolipid' content. Such variability was likely re lated to advected populations having spent variable lengths of time in the area studied. Lipid content and class among organs were studied i n 5 body fractions: abdomen, stomach, digestive gland, gonad and fat b ody. In absolute terms, the highest concentrations were observed in th e ovaries of mature females and the abdomens of the other stages. In r elative terms (% dry weight), the digestive gland displayed the highes t level, except in mature females. Distribution varied with stages, wi th low triglyceride levels in abdomen tissues of most stages and in th e fat body and stomach fractions of subadults. High triglyceride level s were recorded in the other fractions for post spawning females and m ales, as well as in the fat body fraction for mature females and in su badult gonads. A reverse pattern was observed for the relative content of phosphatidyl choline. Phosphatidyl ethanolamine showed maximum val ues in the abdomen and the gonad. Glycolipid percentages were maximum in the abdomen, suggesting a structural role. The roles of the differe nt lipid classes are discussed with respect to the function of the org an.