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

Abstract

ABSTRACT-The content and composition oi lipids in Calanus euxinus females were studied in cyclonic and anticyclonic regions in the southern Black Sea during the period of persistent density stratification (September 1996). The lipid content of C. euxinus from cyclonic regions was greater than of individuals from anticyclonic regions (average 101.9 and 58.8 pg ind.-l, respectively). Total lipid content (mainly wax esters, 70 to 72 %, and triacylglycerols, 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 correlation with chl a was shown also for wax ester content, used as a long-term index of food supply (r = 0.89, p < 0.05).The correlation between triacylglycerol content (a short-term index) and chl a was not significant (r = 0.66, p < 0.2). In cyclonic regions the mean integrated chl a concentration (0.38 mg m-3) (as an indicator of phytoplankton food biomass) was 1.7-fold higher than in anticyclonic areas. The same trend occurred for mean integrated concentrations of nitrate and phosphate (0.996 and 0.299 FM in cyclonic and 0.438 and 0.061 FM in anticyclonic regions, respectively) in the chl a containing layer. Thus, conditions for total primary productivity in cyclonic regions were more favorable than in anticyclonic ones. This was consistent with lipid levels in female C. euxinus.

Seasonal changes in abundance, lipid and fatty acid composition of Calanus euxinus in the South-eastern Black Sea

“…During all seasons, C. euxinus is able to accumulate large amounts of lipids (especially wax esters) in the body (Yuneva et al, 1997(Yuneva et al, , 1999. In the present study, during the sampling period, C. euxinus contained the highest amount of total lipids in February (7.03%) and the lowest in September (3.02%).…”

“…The average amount of total lipids of C. euxinus was 14.1±6.0% at a different station at the South-eastern Black Sea and this proportion decreased to 7.7±5.1% in female C. euxinus living in deeper waters, as reported by Svetlich et al (2006). Yuneva et al (1999) reported on total lipids of female C. euxinus at the Southern Black Sea (September 1996) and indicated that the average amount of total lipids of C. euxinus in cyclonic regions (101.9 µgind -1 ) was greater than that from anticyclonic regions (58.8 µg ind -1 ). It was pointed out that lipid content (wax esters, triacylglycerols) of female C. euxinus was correlated with chl-a (r 2 =0.92, p<0.05).…”

“…Similarly, the correlation between lipid (% and mg ind -1 ) and salinity was also not significant (r 2 =-0.29 and r 2 =-0.02 respectively, p<0.05). Yuneva et al (1999) indicated that the level of lipid accumulation in Calanus depends on the concentration and composition of the phytoplankton consumed. However, in the present study, it was thought that rather than the composition and concentration of the phytoplankton consumed, differences in location and timeframe of the sampling may be a factor in the level of lipid accumulation.…”

Influence of food quality on lipids and essential fatty acids in the body of the Black Sea sprat Sprattus sprattus phalericus (Clupeidae)

“…To determine the proportion of TAGs in TLs, the lipid extract aliquots were separated into fractions by one-dimensional thin layer chromatography (TLC) on Silufoll UW254 plates in a mixture of solvents with different polarity (Yuneva et al, 1999). Chromatograms were developed by heating in a thermostat at 110°C for 5-7 min.…”

Biodiversity in the Black Sea: effects of climate and anthropogenic factors

“…This variability is related to the degree of preparedness for migration, caused by different food supply. The same influence of food supply is seen by comparing the main energy substrates: total lipid content of copepod Calanus euxinus and glycogen content of ctenophora Pleurobrachia rhodopis were different in cyclonic and anticyclonic zones (Yuneva et al, 1999).…”