Evolution of Sensory Systems:
A Comparison of Antarctic and Deep-Sea
Ichthyofauna
John C. Montgomery and John A. Macdonald
Experimental Biology Research Group, School of Biological Sciences, University
of Auckland, Private Bag 92019 Auckland, New Zealand
Introduction
There are many similarities between Antarctic seas and the deep ocean the
principal ones being that both are cold and dark. Antarctic high latitude
basins are effectively dark for the duration of the Antarctic winter. Even
during summer, ice cover extensively reduces light levels, and the
continental shelf is deeper (~600 m) than for other continents (~200 m).
With respect to the fish faunas, the major difference is that the Antarctic
fauna is dominated by members of the suborder Notothenioidei which
belong to the most numerous order of teleost fishes, the Perciformes,
whereas the deep-sea fauna is overwhelmingly composed of nonperciform
fishes. The evidence suggests that Antarctic fishes have evolved under
cold and dark conditions for at most 20 million years (Ma), whereas some
of the nonperciform deep-sea fishes have been evolving in the cold and the
dark for a much greater period, up to 220 Ma. Similar sensory
environments, but different evolutionary time scales, prompt a comparison
of the sensory biology of these two groups of fishes. Interestingly there are
many parallels, but in every case, the sensory adaptations of the deep-sea
fishes are much more extreme than those of their Antarctic counterparts. In
a number of instances attempted comparisons are thwarted by a lack of
data on the appropriate characteristics of Antarctic fishes, so this exercise
provides a fruitful source of questions for further study. The approach of
this paper is to present the broad view of the evolution of the Antarctic and
deep-sea fauna, and then to compare the sensory adaptations of both
faunas concentrating on the most extreme examples. Further information
on the sensory biology of deep-sea fish can be found in Montgomery and
Pankhurst [I].
Evolution of Antarctic and Deep-Sea Faunas
The fossil record shows that 40 Ma ago there was a diverse coastal fish
fauna in Antarctica [2]. However, with the cooling of Antarctica, this early
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
A Comparison of Antarctic and Deep-Sea
Ichthyofauna
John C. Montgomery and John A. Macdonald
Experimental Biology Research Group, School of Biological Sciences, University
of Auckland, Private Bag 92019 Auckland, New Zealand
Introduction
There are many similarities between Antarctic seas and the deep ocean the
principal ones being that both are cold and dark. Antarctic high latitude
basins are effectively dark for the duration of the Antarctic winter. Even
during summer, ice cover extensively reduces light levels, and the
continental shelf is deeper (~600 m) than for other continents (~200 m).
With respect to the fish faunas, the major difference is that the Antarctic
fauna is dominated by members of the suborder Notothenioidei which
belong to the most numerous order of teleost fishes, the Perciformes,
whereas the deep-sea fauna is overwhelmingly composed of nonperciform
fishes. The evidence suggests that Antarctic fishes have evolved under
cold and dark conditions for at most 20 million years (Ma), whereas some
of the nonperciform deep-sea fishes have been evolving in the cold and the
dark for a much greater period, up to 220 Ma. Similar sensory
environments, but different evolutionary time scales, prompt a comparison
of the sensory biology of these two groups of fishes. Interestingly there are
many parallels, but in every case, the sensory adaptations of the deep-sea
fishes are much more extreme than those of their Antarctic counterparts. In
a number of instances attempted comparisons are thwarted by a lack of
data on the appropriate characteristics of Antarctic fishes, so this exercise
provides a fruitful source of questions for further study. The approach of
this paper is to present the broad view of the evolution of the Antarctic and
deep-sea fauna, and then to compare the sensory adaptations of both
faunas concentrating on the most extreme examples. Further information
on the sensory biology of deep-sea fish can be found in Montgomery and
Pankhurst [I].
Evolution of Antarctic and Deep-Sea Faunas
The fossil record shows that 40 Ma ago there was a diverse coastal fish
fauna in Antarctica [2]. However, with the cooling of Antarctica, this early
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998