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
P. Mayzaud et al., 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, Marine ecology. Progress series, 173, 1998, pp. 149-162
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.