ANTAROTIO BENTHOS
167
very large number of bottom photographs obtained on Cruises 32 to 36
of the Eltanin in 1968 have been published by Jacobs, Bruchhausen
and Bauer (1970). Ozawa, Inoue, and Oshita (1968) have published a
few from off Scott Island and off the Balleny Islands.
From a biological point of view, the values to be obtained from
bottom photographs are fairly general. They serve to confirm the type
of assemblage being sampled by dredges or trawls, to give general
impressions of wider areas with occasional animals visible. Unless
sampling, and probably reasonably extensive sampling, is carried out
in the same area as the bottom photograph no certain identification can
be made of organisms visible in the photographs. However, when
sampling and photography are carried out in the same area, additional
and unsuspected results may well be obtained. The deductions made
by Fell (1961) on the feeding habits of ophiuroids in the Ross Sea,
primarily on the evidence presented in bottom photographs is a good
case in point. Similar additional biological facts were deduced by
Newman and Ross (1971) from bottom photographs showing barnacles.
VII. BROODING OR VIVEARITY IN ANTARCTIC ANIMALS
The habit many Antarctic animals have acquired of brooding or
protecting their developing young has been mentioned often in the
literature. Examples have been recorded previously in this work.
Apart from groups like the Isopoda where the habit is widespread
and bivalve families such as the Philobryidae in which it appears
universal, the habit in Antarctica seems to be most strongly developed
in the Echinodermata.
A. Echinodermata
The brooding habit is conspicuous amongst Antarctic holothurians.
At least 15 species (out of a total fauna of 38) have large yolky eggs and
brood their young. Holothurians with this habit either hold the developing young on the dorsal or ventral surface of the body, or carry them in
special pouches or pockets (Pawson, 1969a).
Over 50% of Antarctic comatulids brood their young in some
manner, this percentage being very high. Some 600 comatulids are
known from other areas, and onIy about 1% of these are viviparous.
An important exception in the Antarctic is the subfamily Heliometrinae,
which includes the three most abundant species of Antarctic crinoids
(Dearborn and Rommell, 1969).
Most echinoids pass through a pelagic larval stage-the echinopluteus. In Antarctic echinoids development is often direct with the
female brooding the developing eggs. In the cidaroids the young are
167
very large number of bottom photographs obtained on Cruises 32 to 36
of the Eltanin in 1968 have been published by Jacobs, Bruchhausen
and Bauer (1970). Ozawa, Inoue, and Oshita (1968) have published a
few from off Scott Island and off the Balleny Islands.
From a biological point of view, the values to be obtained from
bottom photographs are fairly general. They serve to confirm the type
of assemblage being sampled by dredges or trawls, to give general
impressions of wider areas with occasional animals visible. Unless
sampling, and probably reasonably extensive sampling, is carried out
in the same area as the bottom photograph no certain identification can
be made of organisms visible in the photographs. However, when
sampling and photography are carried out in the same area, additional
and unsuspected results may well be obtained. The deductions made
by Fell (1961) on the feeding habits of ophiuroids in the Ross Sea,
primarily on the evidence presented in bottom photographs is a good
case in point. Similar additional biological facts were deduced by
Newman and Ross (1971) from bottom photographs showing barnacles.
VII. BROODING OR VIVEARITY IN ANTARCTIC ANIMALS
The habit many Antarctic animals have acquired of brooding or
protecting their developing young has been mentioned often in the
literature. Examples have been recorded previously in this work.
Apart from groups like the Isopoda where the habit is widespread
and bivalve families such as the Philobryidae in which it appears
universal, the habit in Antarctica seems to be most strongly developed
in the Echinodermata.
A. Echinodermata
The brooding habit is conspicuous amongst Antarctic holothurians.
At least 15 species (out of a total fauna of 38) have large yolky eggs and
brood their young. Holothurians with this habit either hold the developing young on the dorsal or ventral surface of the body, or carry them in
special pouches or pockets (Pawson, 1969a).
Over 50% of Antarctic comatulids brood their young in some
manner, this percentage being very high. Some 600 comatulids are
known from other areas, and onIy about 1% of these are viviparous.
An important exception in the Antarctic is the subfamily Heliometrinae,
which includes the three most abundant species of Antarctic crinoids
(Dearborn and Rommell, 1969).
Most echinoids pass through a pelagic larval stage-the echinopluteus. In Antarctic echinoids development is often direct with the
female brooding the developing eggs. In the cidaroids the young are