Seasonal Fluctuations in the Selected Temperature of Speckled Trout, Salvelinus fontinalis (Mitchill)

Abstract

The selected temperature of two- to three-inch trout (Salvelinus fontinalis, Mitchill) was determined in a horizontal gradient a number of times during the months of November, December, January, February and March. The data, which were collected over four years, indicated that during the early part of winter (November, December and January), there was a fall of the selected temperature which paralleled in a general way a gradual fall of the acclimation temperature. The consistency of this parallelism was so poor, however, as to suggest that at least part of the change in selected temperature was relatively independent of the change in acclimation temperature. During the later part of the winter (February and March) there was a rise of the selected temperature which occurred regularly, regardless of whether the acclimation temperature rose, fell or remained constant. It is concluded that there was, for these animals, a seasonal change of the selected temperature which was distinct from the changes in selected temperature brought about by changes of the acclimation temperature.

Behavior of juvenile bluefish Pomatomus saltatrix in vertical thermal gradients: influence of season, temperature acclimation and food

“…Also recognized, though less studied has been the influence of seasonal factors. One of the first demonstrations o f the role that these factors may play was shown in studies by Hart (1952) (Sullivan & Fisher 1953 (Olla et al 1980 (Wilk & Silverman 1976b). In the Black Sea, Oben (1957) (Wilk 1977, Kendall & Walford 1979 1972).…”

“…While thermal history has long been recognized as influencing thermal responses in fish (Fry 1967, Brett 1970, Fry & Hochachka 1970, in terms of thermal distribution, a number of other factors, both biotic and abiotic, have also been found to play an important role. These include season (Sullivan & Fisher 1953, Fry & Hochachka 1970, Olla et al 1980, food availability (Neill & Magnuson 1974), nutritional state (Javaid & Anderson 1967, Stuntz & Magnuson 1976), competition and/or predation , Crowder & Magnuson 1982, time of day (Medvick & Miller 1979), salinity (Garside & Morrison 1977), age (McCauley & Read 1973, Kwain & McCauley 1978, social factors (Medvick et al 1981), pathological condition (Reynolds et al 1976) and habitat requirements (Olla et al , 1980.…”

Thermal tolerance and preference of the Indian catfish Heteropneustes fossilis

“…The experiment performed in summer (May) with catfish collected from their natural habitat (28"-30" C) shows that they fmally preferred to remain in a temperature of around 31.7" C. In the experiment performed on catfish acclimatized to 16" C during winter (December), they initially showed a preference for cool temperatures, but finally preferred to remain in a temperature range from 31.3"-32" C. Thus, the preference of nonacclimated catfish did not vary significantly with the season and in this regard Heteropneustes fossilis is similar to Carassius auratus (Fry 1947(Fry , 1971 and Gillichthys mirabilis (de Vlaming 1971) and contrasts with the seasonal shift in temperature preference shown by the speckled trout (Sullivan & Fisher 1953).…”

Seasonal distribution of American plaice on the northern Grand Banks

“…Season can have a major impact on temperatures selected, possibly through seasonal shifts in metabolic rate (Sullivan & Fisher 1953, Fry & Hochachka 1970, Barans & Tubb 1973. Another factor which may affect the reaction of plaice on the Grand Banks to temperature is avoidance of freezing.…”