|Thermal physiology of the common eelpout (Zoarces viviparus)|Zakhartsev, V.; De Wachter, B.; Sartoris, J.; Portner, O.; Blust, R. (2003). Thermal physiology of the common eelpout (Zoarces viviparus). J. Comp. Physiol. (B Biochem. Syst. Environ. Physiol.) 173(5): 365-378. dx.doi.org/10.1007/s00360-003-0342-z
In: Journal of comparative physiology. Part B. Biochemical, systemic, and environmental physiology. Springer: Heidelberg; Berlin. ISSN 0174-1578, more
critical oxygen concentration; critical temperature; aerobic scope;pejus temperature; geographical distribution
|Authors|| || Top |
- Zakhartsev, V.
- De Wachter, B.
- Sartoris, J.
We investigated the temperature dependence of some physiological parameters of common eelpout (Zoarces viviparus) from different locations (North Sea, Baltic Sea and Norwegian Sea) on acclimation temperature (3 degreesC and 12 degreesC) and acute temperature variation. The lethal limit of 12 degreesC-acclimated eelpout was determined as the critical thermal maximum [loss of equilibrium (LE) and onset of muscular spasms (OS)] and it was found to be 26.6 degreesC for LE and 28.8 degreesC for OS for all populations. However, these parameters do not have any relevant ecological interpretation. We therefore investigated the effect of gradually increased water temperature on standard metabolic rate (measured as resting oxygen consumption Mo-2) and critical oxygen concentration ([O-2](c)) of eelpouts. Acclimation to low temperature (3 degreesC) resulted in partial compensation of Mo-2, paralleled by a decrease of activation energy for Mo-2 (from 82 kJ mol(-1) at 12 degreesC to about 50 kJ mol(-1) at 3 degreesC) in North Sea and Baltic Sea eelpouts. At the same time, Norwegian eelpout showed no acclimation of oxygen demand to warm temperature (12 degreesC) at all. The scope for eelpout aerobic metabolism shrank considerably with increased acclimation temperature, as [O-2](c) approached water oxygen concentrations. At 22.5+/-1 degreesC the [O-2](c) reached air saturation, which is equivalent to the upper critical temperature (Tc-II) and at this temperature the aerobic scope for the metabolism completely disappeared. In line with previous insight, the comparative analysis of the temperature dependence of Mo-2 of Z. viviparus from different populations suggests that a pejus (sub-critical) temperature for this species is about 13-15 degreesC. In conclusion, the capacity to adjust aerobic metabolism relates to thermal tolerance and the bio-geographical distribution of the species. Global warming would thus be likely to cause a shift in the distribution of this species to the North.