ANTARCTIU BENTIIOS
129
surface. However, the major method of oxygen transportation seems
to be through the normal circulatory system (Hemmingsen and Douglas,
1969). The rate of oxygen consumption in Pagetopsis macropterus
Boulenger proved to be one half to one quarter that of other Antarctic
fishes (Hemmingsen, Douglas and Grigg, 1969).
Some work has indicated that the white blood of the Chaenichthyidae is not as sharply differentiated a phenomenon as had been at
first supposed. Two red blooded Antarctic species, Notothenia larseni
Lijnnberg and Trematomus borchrevinki proved to have a reduced
number of erythrocytes and a low haemoglobin count compared with
other fishes (Tyler, 1960). Other Antarctic species may well show
reduced amounts of haemoglobin. The possibility of gaining enough
oxygen from physical solution in the blood plasma may well be correlated with the generally rather sluggish habit and the cold temperatures.
Kooyman (1963) examined four species of Tremtomus from McMurdo Sound and concluded that although the figures for haemoglobin
and erythrocytes were low as compared with temperate fishes, they were
far from lacking them.
As Andriashev (1965, p. 529) pointed out, this family must be considered to be successful biologically. Most species of the family range
along the coasts of the Antarctic Continent, but they also extend to
South Georgia, southern South America and Kerguelen. These habitats
encompass a range of water temperature from -1.95OC up to 5" or
8°C. The species are all of reasonable size, they occur in depths from
the shore to 700 m, they have representatives adapted to benthic and
nektonic habitats.
In the absence of any contrary fossil evidence one can only consider
the family one that has evolved in southern areas, and that the whiteblooded condition is of very considerable age.
4. Trematomus bernucchi
Because of its abundance in many areas around the Antarctic
Continent, and particularly near the United States laboratory at McMurdo Sound, Trematomus bernacchi has been used extensively in
studies on Antarctic fishes. A large amount of information is now
available based upon studies of this species, or using this species as a
base line. Thus the following aspects have now been covered : general
biology (Hureau, 1964a), reproduction (Dearborn, 1965a), diet (Amaud
and Hureau, 1968), metabolic level (Wohlschlag, 1960), growth and
age-determination at freezing temperatures (Wohlschlag, 1961a), metabolic differences between the sexes (Wohlschlag, 1962), respiratory
metabolism and general problems relating to cold adaptation (Wohl-
129
surface. However, the major method of oxygen transportation seems
to be through the normal circulatory system (Hemmingsen and Douglas,
1969). The rate of oxygen consumption in Pagetopsis macropterus
Boulenger proved to be one half to one quarter that of other Antarctic
fishes (Hemmingsen, Douglas and Grigg, 1969).
Some work has indicated that the white blood of the Chaenichthyidae is not as sharply differentiated a phenomenon as had been at
first supposed. Two red blooded Antarctic species, Notothenia larseni
Lijnnberg and Trematomus borchrevinki proved to have a reduced
number of erythrocytes and a low haemoglobin count compared with
other fishes (Tyler, 1960). Other Antarctic species may well show
reduced amounts of haemoglobin. The possibility of gaining enough
oxygen from physical solution in the blood plasma may well be correlated with the generally rather sluggish habit and the cold temperatures.
Kooyman (1963) examined four species of Tremtomus from McMurdo Sound and concluded that although the figures for haemoglobin
and erythrocytes were low as compared with temperate fishes, they were
far from lacking them.
As Andriashev (1965, p. 529) pointed out, this family must be considered to be successful biologically. Most species of the family range
along the coasts of the Antarctic Continent, but they also extend to
South Georgia, southern South America and Kerguelen. These habitats
encompass a range of water temperature from -1.95OC up to 5" or
8°C. The species are all of reasonable size, they occur in depths from
the shore to 700 m, they have representatives adapted to benthic and
nektonic habitats.
In the absence of any contrary fossil evidence one can only consider
the family one that has evolved in southern areas, and that the whiteblooded condition is of very considerable age.
4. Trematomus bernucchi
Because of its abundance in many areas around the Antarctic
Continent, and particularly near the United States laboratory at McMurdo Sound, Trematomus bernacchi has been used extensively in
studies on Antarctic fishes. A large amount of information is now
available based upon studies of this species, or using this species as a
base line. Thus the following aspects have now been covered : general
biology (Hureau, 1964a), reproduction (Dearborn, 1965a), diet (Amaud
and Hureau, 1968), metabolic level (Wohlschlag, 1960), growth and
age-determination at freezing temperatures (Wohlschlag, 1961a), metabolic differences between the sexes (Wohlschlag, 1962), respiratory
metabolism and general problems relating to cold adaptation (Wohl-