Besiktepe, S., L. Svetlichny, T. Yuneva, Z. Romanova & G. Shulman. (2005). Diurnal gut pigment rhythm and metabolic rate of Calanus euxinus in the Black Sea. Marine Biology 146(6):1189-1198.
Besiktepe, S., L. Svetlichny, T. Yuneva, Z. Romanova & G. Shulman
2005
Diurnal gut pigment rhythm and metabolic rate of Calanus euxinus in the Black Sea.
Marine Biology
146(6):1189-1198.
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The vertical distribution, diel gut pigment content and oxygen consumption of Calanus euxinus were studied in April and September 1995 in the Black Sea. Gut pigment content of C. euxinus females was associated with diel vertical migration of the individuals, and it varied with depth and time. Highest gut pigment content was observed during the nighttime, when females were in the chlorophyll a (chl a) rich surface waters, but significant feeding also occurred in the deep layer. Gut pigment content throughout the water column varied from 0.8 to 22.0 ng pigment female À1 in April and from 0.2 to 21 ng pigment female À1 in September 1995. From the diel vertical migration pattern, it was estimated that female C. euxinus spend 7.5 h dayÀ1 in April and 10.5 h day À1 in September in the chl a rich surface waters. Daily consumption by female C. euxinus in chl a rich surface waters was estimated by taking into account the feeding duration and gut pigment concentrations. Daily carbon rations of female C. euxinus, derived from herbivorous feeding in the euphotic zone, ranged from 6% to 11% of their body carbon weight in April and from 15% to 35% in September. Oxygen consumption rates of female and copepodite stage V (CV) C. euxinus were measured at different temperatures and at different oxygen concentrations. Oxygen consumption rates at oxygen-saturated concentration ranged from an average of 0.67 lg O 2 mg À1 dry weight (DW) h À1 at 5°C to 2.1 lg O 2 mg À1 DW h À1 at 23°C for females, and ranged from 0.48 lg O 2 mg À1 DW h À1 at 5°C to 1.5 lg O 2 mg À1 DW h À1 at 23°C for CVs. The rate of oxygen consumption at 16°C varied from 0.62 lg O 2 mg À1 DW h À1 at 0.65 mg O 2 l À1 to 1.57 lg O 2 mgÀ1 DW h À1 at 4.35 mg O 2 l À1 for CVs, and from 0.74 lg O2 mg À1 DW h À1 at 0.57 mg O 2 l À1 to 2.24 lg O 2 mgÀ1 DW h À1 at 4.37 mg O 2 l À1 for females. From the oxygen consumption rates, daily requirements for the routine metabolism of females were estimated, and our results indicate that the herbivorous daily ration was sufficient to meet the routine metabolic requirements of female C. euxinus in April and September in the Black Sea.
