Exercise in the Cold: High Energy Turnover in
Antarctic Fish
Peter L.M. van Dijk, Iris Hardewig, and Hans Otto Portner
Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, 27568
Bremerhaven, Germany
Introduction
Antarctic fishes inhabit one of the world's coldest marine habitats. At high
latitudes the temperatures in the Southern Ocean are close to the freezing
point of seawater at -1.86 °C and display little seasonal variation. The
thermal conditions in the Antarctic have been relatively constant for
several million years. The inhabiting fish fauna has therefore become
highly specialized under the permanent cold conditions of this habitat
which is reflected in a generally low upper lethal temperature of Antarctic
fish at 5-6 °C [I]. In contrast to cold stenothermal polar fish, eurythermal
boreal species must be able to survive a broader temperature range. While
these species may be exposed to similarly cold water temperatures around
o °C during winter, thermal conditions during summer require an elevated
upper lethal temperature limit. On the other hand, eurythermal species are
able to confine high cost metabolic activities like growth and reproduction
to more favorable warmer seasons. Hence, acclimation to seasonal cold in
eurythermal temperate species as opposed to adaptation to cold
stenothermal conditions at high latitudes is associated with different
requirements for the organism and may therefore result in distinct
physiological features.
Recent histological and biochemical investigations suggest that, despite
relatively low resting rates of metabolism, the capacity for aerobic energy
production is enhanced in Antarctic species. Therefore, it may be more
meaningful to investigate situations of high energy flux to determine
whether metabolic cold adaptation does occur in Antarctic fish. The
highest energy flux in fish is observed during burst swimming activity.
Maximum speed is an important factor determining the success of prey
capture and predator avoidance. Therefore, it is crucial for the survival of
individuals and presumably subject to high selective pressures. In the
following review we will summarize the available data on the ability of
cold adapted fish to perform strenuous exercise and to recover from this
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
Antarctic Fish
Peter L.M. van Dijk, Iris Hardewig, and Hans Otto Portner
Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, 27568
Bremerhaven, Germany
Introduction
Antarctic fishes inhabit one of the world's coldest marine habitats. At high
latitudes the temperatures in the Southern Ocean are close to the freezing
point of seawater at -1.86 °C and display little seasonal variation. The
thermal conditions in the Antarctic have been relatively constant for
several million years. The inhabiting fish fauna has therefore become
highly specialized under the permanent cold conditions of this habitat
which is reflected in a generally low upper lethal temperature of Antarctic
fish at 5-6 °C [I]. In contrast to cold stenothermal polar fish, eurythermal
boreal species must be able to survive a broader temperature range. While
these species may be exposed to similarly cold water temperatures around
o °C during winter, thermal conditions during summer require an elevated
upper lethal temperature limit. On the other hand, eurythermal species are
able to confine high cost metabolic activities like growth and reproduction
to more favorable warmer seasons. Hence, acclimation to seasonal cold in
eurythermal temperate species as opposed to adaptation to cold
stenothermal conditions at high latitudes is associated with different
requirements for the organism and may therefore result in distinct
physiological features.
Recent histological and biochemical investigations suggest that, despite
relatively low resting rates of metabolism, the capacity for aerobic energy
production is enhanced in Antarctic species. Therefore, it may be more
meaningful to investigate situations of high energy flux to determine
whether metabolic cold adaptation does occur in Antarctic fish. The
highest energy flux in fish is observed during burst swimming activity.
Maximum speed is an important factor determining the success of prey
capture and predator avoidance. Therefore, it is crucial for the survival of
individuals and presumably subject to high selective pressures. In the
following review we will summarize the available data on the ability of
cold adapted fish to perform strenuous exercise and to recover from this
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998