Age, Growth and Maximum Size of Antarctic
N otothenioid Fish - Revisited
Karl-Hermann Kock' and Inigo Everson 2
'Institut flir Seefischerei, BFA flir F ischerei, Palmaille 9, 22767 Hamburg,
Germany
2British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET,
UK
Introduction
The temperature of the Southern Ocean has undergone an overall
reduction from about 20 °e to -1.8 °e over the last 55-60 million years.
To date, the Southern Ocean is characterized by low temperatures ranging
from +3 °e close to the South Polar Frontal Zone to -1.86 °e in the
vicinity of the Antarctic continent and a strong seasonality and patchiness
of primary productivity.
The Antarctic coastal fish fauna consists of about 140 species of 18
families [1]. This fauna is dominated both in terms of species and biomass
by a single endemic perciform suborder, the Notothenioidei.
Notothenioidei comprise a variety of ecomorphological types ranging
from small sculpin-like to large hake-like forms [1-3]. Two coarse groups
of coastal species can be distinguished according to their geographical
distribution: lesser-Antarctic/subAntarctic species and high-Antarctic
species [4]. Although low temperature has most likely played a dominant
role in the evolution of the present fish fauna, other factors, such as
climatic cycles, isolation, habitat loss, and seasonality in food availability
have probably also been important [2].
Antarctic notothenioid fish show a variety of adaptations at the
molecular level, such as freezing resistance, tubulins, which polymerize at
-2 °e, the conductivity of neurones and high turnover rates of enzymes, in
order to maintain function in their extreme thermal environment [2,5]. The
rates of complex physiological systems are frequently slower in Antarctic
species than in temperate species. Growth is a complex process that is
subject to a number of controls and limitations at a variety of levels,
which makes it difficult to determine which particular factor is the
strongest in controlling growth rate [6]. Temperature and other
environmental variables, such as light levels, food availability and quality,
reproduction and activity are all likely to affect growth [6-9].
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
N otothenioid Fish - Revisited
Karl-Hermann Kock' and Inigo Everson 2
'Institut flir Seefischerei, BFA flir F ischerei, Palmaille 9, 22767 Hamburg,
Germany
2British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET,
UK
Introduction
The temperature of the Southern Ocean has undergone an overall
reduction from about 20 °e to -1.8 °e over the last 55-60 million years.
To date, the Southern Ocean is characterized by low temperatures ranging
from +3 °e close to the South Polar Frontal Zone to -1.86 °e in the
vicinity of the Antarctic continent and a strong seasonality and patchiness
of primary productivity.
The Antarctic coastal fish fauna consists of about 140 species of 18
families [1]. This fauna is dominated both in terms of species and biomass
by a single endemic perciform suborder, the Notothenioidei.
Notothenioidei comprise a variety of ecomorphological types ranging
from small sculpin-like to large hake-like forms [1-3]. Two coarse groups
of coastal species can be distinguished according to their geographical
distribution: lesser-Antarctic/subAntarctic species and high-Antarctic
species [4]. Although low temperature has most likely played a dominant
role in the evolution of the present fish fauna, other factors, such as
climatic cycles, isolation, habitat loss, and seasonality in food availability
have probably also been important [2].
Antarctic notothenioid fish show a variety of adaptations at the
molecular level, such as freezing resistance, tubulins, which polymerize at
-2 °e, the conductivity of neurones and high turnover rates of enzymes, in
order to maintain function in their extreme thermal environment [2,5]. The
rates of complex physiological systems are frequently slower in Antarctic
species than in temperate species. Growth is a complex process that is
subject to a number of controls and limitations at a variety of levels,
which makes it difficult to determine which particular factor is the
strongest in controlling growth rate [6]. Temperature and other
environmental variables, such as light levels, food availability and quality,
reproduction and activity are all likely to affect growth [6-9].
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998