The physiological response of Northern krill (Meganyctiphanes norvegica) to temperature gradients in the Kattegat
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The Alkor-Deep (140 m), which forms part of a depression system in the northern Kattegat channel east of the island of Læsø (Denmark), is the location of a self sustaining population of Northern krill, Meganyctiphanes norvegica (Euphausiacea). This population is exposed to one of the most pronounced thermal gradients within the distributional range of this pelagic crustacean. During summer, the temperature of the water column ranges between 4 and 6 in the deep to 16 °C near the surface which results in the krill being exposed to temperature differences of 8–10 °C during diel vertical migration. Oxygen consumption rates were used to investigate the physiological adaptation of the animal to such gradients in temperature. The rates were found to increase exponentially from 31 μmol O2 h-1 gdw-1 at 4 °C to 72 μmol O2 h-1 gdw-1 at 16 °C, giving a Q10-value of 2.0, and indicating that physiological adaptation to varying thermal conditions does not take place. Behavioural adaptations are discussed which may help the krill to cope with large temperature gradients in their environment.
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- Boysen, E. & F. Buchholz, 1984. Meganyctiphanes norvegica in the Kattegat: studies on the annual development of a pelagic population. Mar. Biol. 79: 195–207.Google Scholar
- Buchholz, F. & E. Boysen-Ennen, 1988. Meganyctiphanes norvegica in the Kattegat: studies on the horizontal distribution in relation to hydrography and zooplankton. Ophelia 29: 71–82.Google Scholar
- Buchholz, F., C. Buchholz, J. Reppin & J. Fischer, 1995. Diel vertical migrations of Meganyctiphanes norvegica in the Kattegat: comparison of net catches and measurements with acoustic doppler current profilers. Helgoländer Meeresunters. 49: 849–866.Google Scholar
- Hirche, H.-J., 1984. Temperature and metabolism of plankton-1. Respiration of Antarctic zooplankton at different temperatures with a comparison of Antarctic and Nordic krill. Comp. Biochem. Physiol. 77A: 361–368.Google Scholar
- Mauchline, J. & L. R. Fisher, 1969. The Biology of Euphausiids. Adv. Mar Biol. 7: 1–545.Google Scholar
- Saborowski, R. & F. Buchholz, 1998. Internal current generation in respiration chambers. Helgoländer Meeresunters. 52: 103–109.Google Scholar
- Tarling, G. A., J. B. L. Matthews, R. Saborowski & F. Buchholz, 1998. Vertical migratory behaviour of the euphausiid, Meganyctiphanes norvegica, and its dispersion in the Kattegat Channel. Hydrobiologia 375/376 (Dev. Hydrobiol. 132): 331–341.Google Scholar
- Ulrich, V. J., 1983. Zur Bathymetrie und Topographie der nördlichen Kattegat-Rinne. Meeresforsch. 30: 61–68.Google Scholar
- Wiebe, P. H., A. W. Morton, A. M. Bradley, R. H. Backus, J. E. Craddock, V. Barber, T. J. Cowles & G. R. Flierl, 1985. New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Mar. Biol. 87: 313–323.Google Scholar