Metabolic adaptations and reduced respiration of the copepod Calanoides carinatus during diapause at depth in the Angola-Benguela Front and northern Benguela upwelling regions
Auel, H.; Hagen, W.; Ekau, W.; Verheye, H.M. (2005). Metabolic adaptations and reduced respiration of the copepod Calanoides carinatus during diapause at depth in the Angola-Benguela Front and northern Benguela upwelling regions. Afr. J. Mar. Sci. 27(3): 653-657. https://dx.doi.org/10.2989/18142320509504125
In: African Journal of Marine Science. NISC/Taylor & Francis: Grahamstown. ISSN 0257-7615; e-ISSN 1814-2338, more
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| Keywords |
Calanoides carinatus (Krøyer, 1849) [WoRMS]; Copepoda [WoRMS]
Marine/Coastal |
| Author keywords |
CALANOIDES CARINATUS, COASTAL UPWELLING REGION, COPEPOD, DIAPAUSE, LIFE CYCLE, METABOLISM, OXYGEN, RESPIRATION, SOUTH ATLANTIC |
| Authors | | Top |
- Auel, H.
- Hagen, W.
- Ekau, W.
- Verheye, H.M.
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| Abstract |
Stage C5 copepodids and adult females of the herbivorous copepod Calanoides carinatus were sampled in the Angola-Benguela frontal region and northern Benguela upwelling area off Namibia in February–March 2002, using a multiple opening/closing net system. Respiration rates of C5s collected between 400m and 700m were measured onboard at the simulated in situ temperature of 8°C and at sea surface temperature (SST =20°C). These data were compared to the oxygen demand of epipelagic individuals of C. carinatus caught in the upper 30m and incubated at ambient SST. Deep-living C5s consumed 0.21 ± 0.08ml O2 h-1 (g dry mass)-1 at 8°C and 0.96ml O2 h-1 (g dry mass)-1 (range 0.84–1.09) at 25.9°C. These results were substantially lower than respiration rates of 5.23 ± 0.55ml O2 h-1 (g dry mass)-1 in epipelagic individuals incubated at SST. The results reveal a reduction by 96% of metabolic rate in deep-living, diapausing C5s relative to surface-dwelling, active individuals. Only 14.4% of this metabolic reduction is explained by the lower ambient temperature at depth and a Q10 value of 2.34. Therefore, the major fraction (81.6%) of the metabolic reduction is attributable to active physiological changes or processes during diapause at depth. The study emphasises the importance for herbivorous copepods, in areas with a highly variable food supply, to adopt a dormant phase in their life cycle in order to survive long periods of starvation. |
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