EFFECTS OF HEATED EFFLUENTS
73
species are capable of considerable acclimatization over a wide range
of temperatures. This follows from numerous observations that the
rates of various physiological activities within members of one species
or between closely related species vary predictably with seasonal,
spatial and experimental variations in temperature (Bullock, 1955).
Mechanisms of acclimatization are reviewed and discussed by Kinne
(1963) and are beyond the scope of the present discussion. Here it is
relevant to consider the effects which a rise in water temperature might
have upon different systematic groups of animals and upon different
marine communities.
In coelenterates latitudinal acclimatization has been demonstrated
in Aurelia aurita (L.), which show maximal swimming activity at higher
or lower temperatures according to the latitude from which they are
collected. Thus specimens from Halifax, Nova Scotia, collected from
water at 14"C, showed maximal pulsations of the bell between 0" and
27°C whereas specimens from water at 29°C in Tortugas, Florida,
showed maximal activity over the temperature range 13-36°C (Mayer,
1914). Similarly, Cyanea capillata (L.), a cold-water stenotherm,
pulsates at about the same rate at 15°C as Cassiopeia xanutchana R. P.
Bigelow, a closely related tropical form, does at 29°C (Mayer, 1914).
Geographical temperature compensation of this kind, in metabolism,
development and activity, has also been demonstrated in a variety of
poikilotherms, particularly polychaetes and crustacea (Fox, 1936, 1938,
1939 ; Fox and Wingfield, 1937 ; and Wingfield, 1939) and, more recently,
in a shore crab Pachygrapsus crassipes Randall (Roberts, 1953, 1957),
the amphipod Gamarus duebeni (Kinne, 195313) and Balanus bakcnoides
(Crisp, 1964b). Pachygrapsus appeared to show no acclimatization to
monthly changes in temperature, but short-term unseasonable changes
in temperature seemed to be reflected in metabolism and behavioural
activity (Roberts, 1957). Amongst other crustacea changes in metabolism associated with seasonal variations in temperature have been
demonstrated in the sand crab Emerita (Edwards and Irving, 1943a),
the beach amphipod Talorchestia (Edwards and Irving, 1943b) and
probably also in the copepod Calanus finmarchicus (Marshall et al.,
1936). Halcrow (1963) confirmed that the acclimatization takes place
in Calanus finmarchicus (Gunnerus) but showed that it was possible
only within the normal seasonal range of temperature in the water from
which specimens were collected. This ability to compensate for changes
of temperature within the normal seasonal range of variation has also
been observed in various rhythmic activities of decapod crustacea.
These include rhythms of chromatophore expansion and contraction
in the fiddler crab Uca (Brown and Webb, 1948), the blue crab Callinectes
73
species are capable of considerable acclimatization over a wide range
of temperatures. This follows from numerous observations that the
rates of various physiological activities within members of one species
or between closely related species vary predictably with seasonal,
spatial and experimental variations in temperature (Bullock, 1955).
Mechanisms of acclimatization are reviewed and discussed by Kinne
(1963) and are beyond the scope of the present discussion. Here it is
relevant to consider the effects which a rise in water temperature might
have upon different systematic groups of animals and upon different
marine communities.
In coelenterates latitudinal acclimatization has been demonstrated
in Aurelia aurita (L.), which show maximal swimming activity at higher
or lower temperatures according to the latitude from which they are
collected. Thus specimens from Halifax, Nova Scotia, collected from
water at 14"C, showed maximal pulsations of the bell between 0" and
27°C whereas specimens from water at 29°C in Tortugas, Florida,
showed maximal activity over the temperature range 13-36°C (Mayer,
1914). Similarly, Cyanea capillata (L.), a cold-water stenotherm,
pulsates at about the same rate at 15°C as Cassiopeia xanutchana R. P.
Bigelow, a closely related tropical form, does at 29°C (Mayer, 1914).
Geographical temperature compensation of this kind, in metabolism,
development and activity, has also been demonstrated in a variety of
poikilotherms, particularly polychaetes and crustacea (Fox, 1936, 1938,
1939 ; Fox and Wingfield, 1937 ; and Wingfield, 1939) and, more recently,
in a shore crab Pachygrapsus crassipes Randall (Roberts, 1953, 1957),
the amphipod Gamarus duebeni (Kinne, 195313) and Balanus bakcnoides
(Crisp, 1964b). Pachygrapsus appeared to show no acclimatization to
monthly changes in temperature, but short-term unseasonable changes
in temperature seemed to be reflected in metabolism and behavioural
activity (Roberts, 1957). Amongst other crustacea changes in metabolism associated with seasonal variations in temperature have been
demonstrated in the sand crab Emerita (Edwards and Irving, 1943a),
the beach amphipod Talorchestia (Edwards and Irving, 1943b) and
probably also in the copepod Calanus finmarchicus (Marshall et al.,
1936). Halcrow (1963) confirmed that the acclimatization takes place
in Calanus finmarchicus (Gunnerus) but showed that it was possible
only within the normal seasonal range of temperature in the water from
which specimens were collected. This ability to compensate for changes
of temperature within the normal seasonal range of variation has also
been observed in various rhythmic activities of decapod crustacea.
These include rhythms of chromatophore expansion and contraction
in the fiddler crab Uca (Brown and Webb, 1948), the blue crab Callinectes