Journal of Comparative Physiology B

, Volume 173, Issue 5, pp 365–378

Thermal physiology of the common eelpout (Zoarces viviparus)

Authors

    • Department of BiologyUniversity of Antwerp, University of Antwerp—RUCA
  • B. De Wachter
    • Department of BiologyUniversity of Antwerp, University of Antwerp—RUCA
  • F. J. Sartoris
    • Marine Biology/Ecological PhysiologyAlfred-Wegener-Institute
  • H. O. Pörtner
    • Marine Biology/Ecological PhysiologyAlfred-Wegener-Institute
  • R. Blust
    • Department of BiologyUniversity of Antwerp, University of Antwerp—RUCA
Original Paper

DOI: 10.1007/s00360-003-0342-z

Cite this article as:
Zakhartsev, M.V., De Wachter, B., Sartoris, F.J. et al. J Comp Physiol B (2003) 173: 365. doi:10.1007/s00360-003-0342-z

Abstract

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 °C and 12 °C) and acute temperature variation. The lethal limit of 12 °C-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 °C for LE and 28.8 °C 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 Mo2) and critical oxygen concentration ([O2]c) of eelpouts. Acclimation to low temperature (3 °C) resulted in partial compensation of Mo2, paralleled by a decrease of activation energy for Mo2 (from 82 kJ mol–1 at 12 °C to about 50 kJ mol–1 at 3 °C) in North Sea and Baltic Sea eelpouts. At the same time, Norwegian eelpout showed no acclimation of oxygen demand to warm temperature (12 °C) at all. The scope for eelpout aerobic metabolism shrank considerably with increased acclimation temperature, as [O2]c approached water oxygen concentrations. At 22.5±1 °C the [O2]c reached air saturation, which is equivalent to the upper critical temperature (TcII) 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 Mo2 of Z. viviparus from different populations suggests that a pejus (sub-critical) temperature for this species is about 13–15 °C. 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.

Keywords

Critical oxygen concentrationCritical temperatureAerobic scopePejus temperatureGeographical distribution

Abbreviations

CTMax

critical thermal maximum

Fiv

factor of inside volume

GT

total oxygen conductance

LE

loss of equilibrium

LT50

time period of exposure when mortality reaches 50%

MO2

rate of oxygen consumption

MO2o

rate of oxygen consumption at 0 °C

[O2]c

critical oxygen concentration

OS

onset of muscular spasms

Tc

critical temperature

Tcll

upper critical temperature

Tp

pejus temperature

Copyright information

© Springer-Verlag 2003