Lipids and life strategies of Calanus finmarchicus, Calanus glacialis and Calanus hyperboreus in late autumn, Kongsfjorden, Svalbard

Stage IV and V copepodites were the dominant forms of Calanus finmarchicus, C. glacialis and C. hyperboreus in Kongsfjorden in late September 1997. Stage IV and V copepodites of C. glacialis and C, hyperboreus were rich in lipid, largely wax esters, and were well fitted to overwinter. Stage IV copepodites of C. finmarchicus were also rich in wax esters, but stage V copepodites of C. finmarchicus were less wax ester-rich. Large size increments between stage IV and V copepodites and between stage V copepodites and females were noted in C. finmarchicus. A very large increment between stage IV and V copepodites was noted for C. glacialis but the size difference between stage V copepodites and females was very small in this species. Particularly large increments were noted between stage IV and V copepodites of C. hyperboreus and also between stage V copepodites and females of this species. The very large, wax ester-rich C. hyperboreus is well adapted to survive the most extreme variations in the Arctic. in Arctic basin waters. whereas the smaller, wax ester-rich C. glacialis is adapted to survive less extreme Arctic variations, as in Arctic shelf waters. The smallest of the three. C. finmarchicus, is best adapted to survive the more predictable waters of the North Atlantic and the Barents Sea.