ANTARCTIC BENTHOS
77
1933) and the Valvifera (Sheppard, 1957). The group in the Antarctic
has received little attention in the last few decades, however, even the
Discovery collections not having been written up completely. Nor was
there any general account of the Antarctic fauna nor any attempt to
analyse its relationships or biogeography.
The large paper by Kusakin (1967) describing the results of recent
Soviet expeditions and containing a very full discussion of distribution
and faunal relationships is particularly welcome. Kusakin also presents
a short historical summary of all work on the group in the Subantarctic
and contiguous areas and indicates areas for which information is
lacking. He stresses that a group such as the isopods, since most are
bottom dwelling animals, do not migrate extensively, carry their
young with them and occur in numbers in most seas, are a particularly
useful group to consider for biogeographical evidence.
Kusakin (1 967) considered that 180 species of Isopoda and Tanaidacea were to be found in the Antarctic. Of these 66% were endemic to
the Antarctic. Of the 69 genera represented only six are endemic,
i.e. Zenobianopsis, Clyptonotus, Dolichiscus, Ectias, Notoxenus and
Echinomunna.
The Antarctic isopods represent no less than 26 of the 30 families
known from the Southern Hemisphere outside the tropics and subtropics. The ones missing are three widely dispersed families (Jaeropsidae, Corallinidae and Cymothoidae), and one endemic to the Patagonia
region (Xenarcturidae). Far more than for most other groups investigated the Antarctic isopod fauna is much less restricted. One of the
characteristics of the Antarctic fauna is the abundance of species down
to 400 or 700 m, instead of a falling off in numbers in depths of 200 m
or more as in other parts of the world.
The genera best represented are Serolis with 23 species and Antarcturus with 20. Although not confined to the Antarctic these two genera
are undoubtedly best represented here. The number of species steadily
decreases to the north. The family Munnidae with nine genera and 30
species, is also well represented. The family Idoteidae, which is usually
well represented with genera and species, has only three genera in the
Antarctic, two of which, Glyptonotus and Zenobianopsis are endemic.
Kusakin (1967) divides the Antarctic for purposes of analysis into
four zones.
1. From Eights Coast to Adelie Land (lOOoW to 140"E)-" Pacific
Ocean Sector ".
2. From Wilkes Land to Princess Ragnhild Coast (140"E to 15"E)" Indian Sector ".
3. Princess Martha Coast to the Bellingshausen Sea (16"E to l00"W)
77
1933) and the Valvifera (Sheppard, 1957). The group in the Antarctic
has received little attention in the last few decades, however, even the
Discovery collections not having been written up completely. Nor was
there any general account of the Antarctic fauna nor any attempt to
analyse its relationships or biogeography.
The large paper by Kusakin (1967) describing the results of recent
Soviet expeditions and containing a very full discussion of distribution
and faunal relationships is particularly welcome. Kusakin also presents
a short historical summary of all work on the group in the Subantarctic
and contiguous areas and indicates areas for which information is
lacking. He stresses that a group such as the isopods, since most are
bottom dwelling animals, do not migrate extensively, carry their
young with them and occur in numbers in most seas, are a particularly
useful group to consider for biogeographical evidence.
Kusakin (1 967) considered that 180 species of Isopoda and Tanaidacea were to be found in the Antarctic. Of these 66% were endemic to
the Antarctic. Of the 69 genera represented only six are endemic,
i.e. Zenobianopsis, Clyptonotus, Dolichiscus, Ectias, Notoxenus and
Echinomunna.
The Antarctic isopods represent no less than 26 of the 30 families
known from the Southern Hemisphere outside the tropics and subtropics. The ones missing are three widely dispersed families (Jaeropsidae, Corallinidae and Cymothoidae), and one endemic to the Patagonia
region (Xenarcturidae). Far more than for most other groups investigated the Antarctic isopod fauna is much less restricted. One of the
characteristics of the Antarctic fauna is the abundance of species down
to 400 or 700 m, instead of a falling off in numbers in depths of 200 m
or more as in other parts of the world.
The genera best represented are Serolis with 23 species and Antarcturus with 20. Although not confined to the Antarctic these two genera
are undoubtedly best represented here. The number of species steadily
decreases to the north. The family Munnidae with nine genera and 30
species, is also well represented. The family Idoteidae, which is usually
well represented with genera and species, has only three genera in the
Antarctic, two of which, Glyptonotus and Zenobianopsis are endemic.
Kusakin (1967) divides the Antarctic for purposes of analysis into
four zones.
1. From Eights Coast to Adelie Land (lOOoW to 140"E)-" Pacific
Ocean Sector ".
2. From Wilkes Land to Princess Ragnhild Coast (140"E to 15"E)" Indian Sector ".
3. Princess Martha Coast to the Bellingshausen Sea (16"E to l00"W)