Nutritional condition of female Calanus euxinus from cyclonic and anticyclonic regions of the Black Sea

The content and composition of lipids in Calanus euxinus females were studi ed in cyclonic and anticyclonic regions in the southern Black Sea during th e period of persistent density stratification (September 1996). The lipid c ontent of C, euxinus from cyclonic regions was greater than of individuals from anticyclonic regions (average 101.9 and 58.8 mu g ind.(-1), respective ly). Total Lipid content (mainly wax esters, 70 to 72%, and triacylglycerol s, 8 to 13%) of female C. euxinus was correlated with chlorophyll a (chl a) (mean integrated concentration) (r = 0.92, p < 0.005). The high correlatio n with chi a was shown also for wax ester content. used as a long-term inde x of food supply (r = 0.89, p < 0.05). The correlation between triacylglyce rol content (a short-term index) and chi a was not significant (r = 0.66, p < 0.2). In cyclonic regions the mean integrated chi a concentration (0.38 mg m(-3)) (as an indicator of phytoplankton food biomass) was 1.7-fold high er than in anticyclonic areas. The same trend occurred for mean integrated concentrations of nitrate and phosphate (0.996 and 0.299 mu M in cyclonic a nd 0.438 and 0.061 mu M in anticyclonic regions. respectively) in the chi a containing layer. Thus, conditions for total primary productivity in cyclo nic regions were more favorable than in anticyclonic ones. This was consist ent with lipid levels in female C, euxinus.