ANTARCTIC BENTHOS
167
the fauna originated on the southern extremity of South America.
Judging by the evidence from other groups it seems highly probable
that both views will prove to be partly true.
The outstanding feature of the Antarctic fish fauna is the almost
overwhelming part played by the superfamily, the Nototheniiformes.
The diversity of habit shown by the members of the superfamily, the
fact that one family has acquired the unique feature of whitebloodednew, and the unique mechanisms developed for cold adaptation all bear
out the contention of Regan (1914b), Norman (1938) and Andriashev
(1965) that this group could only have developed in an area that was
isolated fairly effectively probably throughout the Tertiary.
The four Antarctic families of the Nototheniiformes, together with
the Muraenolepidae make up an old endemic element, possibly with
long term connections with South America (Andriashev, 1965). The
Congiopodidae represent a later invasion by a widespread Southern
Hemisphere family. Its occurrence together with occasional representatives of such families as the Rajidae and the Bothidae is not surprising,
although the few families so represented is unusual. The Antarctic
members of the two primarily boreal families, Zoarcidae and Liparidae,
have obviously been derived immediately from southern South America.
Another faunal group has obviously been derived from widely distributed deeper water families, e.g. the Macruridae and Brotulidae.
Andriashev (1966) concluded his discussion of Antarctic fish origins,
( ( Thus, by its ancient roots and to a lesser extent by modern influence
the Antarctic fauna of bottom fishes is connected with the coldtemperate (subantarctic) South American fauna. Considerably weaker
are the links with the New Zealand fauna. . . . There is practically no
relation to other regions of the southern hemisphere ”.
The above statement relating to fishes could be repeated with slight
variations for group after group of Antarctic organisms. An ancient
element which may have developed into a single endemic genus or
species, or which occasionally has radiated into numerous species,
genera, or much more rarely endemic families, has often established
itself widely within the confines of the Antarctic Continent. More
recent invasions may show more obvious, and more recent relationships
with southern South America, or with the more widely dispersed Subantarctic Islands.
Only one great migration route may have existed into Antarctica,
and out of Antarctica, throughout the Tertiary in the form of the Scotia
Arc. This should never be envisaged as a great broad highway along
which South American species marched in their steady echelons into
Antarctica. The Scotia Ridge has probably always acted as a filtering
167
the fauna originated on the southern extremity of South America.
Judging by the evidence from other groups it seems highly probable
that both views will prove to be partly true.
The outstanding feature of the Antarctic fish fauna is the almost
overwhelming part played by the superfamily, the Nototheniiformes.
The diversity of habit shown by the members of the superfamily, the
fact that one family has acquired the unique feature of whitebloodednew, and the unique mechanisms developed for cold adaptation all bear
out the contention of Regan (1914b), Norman (1938) and Andriashev
(1965) that this group could only have developed in an area that was
isolated fairly effectively probably throughout the Tertiary.
The four Antarctic families of the Nototheniiformes, together with
the Muraenolepidae make up an old endemic element, possibly with
long term connections with South America (Andriashev, 1965). The
Congiopodidae represent a later invasion by a widespread Southern
Hemisphere family. Its occurrence together with occasional representatives of such families as the Rajidae and the Bothidae is not surprising,
although the few families so represented is unusual. The Antarctic
members of the two primarily boreal families, Zoarcidae and Liparidae,
have obviously been derived immediately from southern South America.
Another faunal group has obviously been derived from widely distributed deeper water families, e.g. the Macruridae and Brotulidae.
Andriashev (1966) concluded his discussion of Antarctic fish origins,
( ( Thus, by its ancient roots and to a lesser extent by modern influence
the Antarctic fauna of bottom fishes is connected with the coldtemperate (subantarctic) South American fauna. Considerably weaker
are the links with the New Zealand fauna. . . . There is practically no
relation to other regions of the southern hemisphere ”.
The above statement relating to fishes could be repeated with slight
variations for group after group of Antarctic organisms. An ancient
element which may have developed into a single endemic genus or
species, or which occasionally has radiated into numerous species,
genera, or much more rarely endemic families, has often established
itself widely within the confines of the Antarctic Continent. More
recent invasions may show more obvious, and more recent relationships
with southern South America, or with the more widely dispersed Subantarctic Islands.
Only one great migration route may have existed into Antarctica,
and out of Antarctica, throughout the Tertiary in the form of the Scotia
Arc. This should never be envisaged as a great broad highway along
which South American species marched in their steady echelons into
Antarctica. The Scotia Ridge has probably always acted as a filtering