The Effects of Light on Temperature Selection in Speckled Trout Salvelinus Fontinalis (Mitchill)

Thermal selection behaviour in the estuarine goby Gillichthys mirabilis Cooper

“…The selected temperature in fish is a labile characteristic whose value has been shown to depend not only on the species, but also on acclimation temperature (Fry, 1947;Pitt et al, 1956;Ferguson, 1958). Light may alter the selected temperature, and there is some evidence that there is an inverse relationship between light intensity and the precision of selection (Sullivan & Fisher, 1954;Ferguson, 1958). Sullivan & Fisher (1953) noted a seasonal increase in the preferendum of brook trout at the time of the vernal equinox; otherwise, seasonal variation in fish thermal preferences have not been explored.…”

“…Many factors such as dissolved gases, light, shelter positions, and current have been shown to modify thermal responses in fish (Sullivan & Fisher, 1954;Norris, 1963;Fry, 1964). Although consideration of most of these variables was not included in this study, results presented here suggest that, in this species, preference for darkness is subjugated by thermal responses.…”

“…Light may alter the selected temperature, and there is some evidence that there is an inverse relationship between light intensity and the precision of selection (Sullivan & Fisher, 1954;Ferguson, 1958). Sullivan & Fisher (1953) noted a seasonal increase in the preferendum of brook trout at the time of the vernal equinox; otherwise, seasonal variation in fish thermal preferences have not been explored.…”

The Functions of Temperature in the Ecology of the Percoid Fish Girella nigricans (Ayres)

“…The temperature sensing systems of fishes have been the subject of several studies. Dijkgraaf (1940) and Sullivan (1949) both showed that cutaneous receptors and not the lateral-line system are necessary for temperature reception. Krause (1923) found that the skin of pike (Esox) is well supplied with small nerve fibers which terminate without detectable specialized endings.…”

“…In view of the prevalence of temperature-related movements and thermal faunal restrictions, the question arises: How does a fish receive environmental information, and of what kind, to react in such a way as to remain within its thermal zone? Does this involve a kinesis as suggested by Sullivan (1949) in which temperature simply alters a component of movement, which tends to return the fish to its proper environment, or does it involve reception of and reaction to a temperature differential along the length of the fish's body? An additional alternative would be that a fish moving in a uniform temperature water mass would tend to reach temperature equilibrium with the surrounding sea (which might involve a complex thermal gradient within the fish's body as a result of metabolic heat production) but as soon as the fish moved into a different thermal situation this equilibrium would be altered and could be sensed, even if the thermal change in the environment was too gradual to be sensed as an instantaneous differential along the length of the body.…”