LIPID CONTENTS OF 5 SPECIES OF NOTOTHENIOID FISH FROM HIGH-ANTARCTIC WATERS AND ECOLOGICAL IMPLICATIONS

Comprehensive data are presented on the total lipid contents of five s pecies of notothenioid fish collected during summer 1991 in the Weddel l Sea and the Lazarev Sea south of 69 degrees S. The species were sele cted based on their different modes of life, benthic, benthopelagic an d pelagic, to examine how the life style - among other factors - affec ts the proximate composition of these high-Antarctic fishes. Lipid con tents of whole specimens showed an extremely wide range from 3.1 to 67 .5% of dry weight (%DW), with corresponding carbon/nitrogen (C/N) rati os between 3.4 and 11.3. Lowest lipid contents were found in the benth ic species Bathydraco marri and Dolloidraco longedorsalis with means o f 11.0 and 11.9 %DW. The benthopelagic Trematomus lepidorhinus had an intermediate mean lipid content of 20.8 %DW, and the pelagic species P leuragramma antarcticum and Aethotaxis mitopteryx were richest in lipi d with means of 47.0 %DW and 60.8 %DW. There was a pronounced ontogene tic lipid accumulation with increasing size discernible in the lipid-r ich species, especially in P. antarcticum. No clear relationship was f ound between lipid content and sex or maturity in A. mitopteryx and T. lepidorhinus, only the males of B. marri had higher lipid contents th an the females. Lipid contents and water contents were inversely corre lated. In conclusion, the mode of life of these species was clearly re flected by their lipid contents and lipids seem to have an important f unction, particularly as buoyancy aids in the pelagic species, which l ike all notothenioids lack a swim-bladder.