The final thermal preferendum of fishes: Shuttling behavior and acclimation overshoot

Abstract

The concept of final preferendum is reexamined in light of data concerning acclimation in a cyclic thermal regime . Because of shuttling behavior' to temperatures above and below the mean preferendum, and because of faster acclimation `upward' thaǹ downward', which result in acclimation to a temperature exceeding the mean of the cycle, a fish may finally gravitate to a preferendum which does not equal acclimation temperature . It is suggested that a distinction be made between the 'crossoverpoint' preferendum, where preference and acclimation are equal, and the 'ultimate' preferendum to which a fish will ultimately gravitate.

Thermoregulatory behavior of brown trout, Salmo trutta

“…The single fish tested for more than a week showed erratic thermoregulatory performance and a shift to lower temperatures after the first 4 days, a phenomenon noted with other species and as yet poorly understood (cf . Reynolds, 1977cReynolds, , 1978 . …”

“…Following an initial 24 hour introductory period to allow gravitation to the final preferendum (Reynolds, 1977c(Reynolds, , 1978, data were collected over the ensuing 48 hours . One fish was tested for a longer period of over a week .…”

Thermal ecology of red lionfish Pterois volitans from southeast Sulawesi, Indonesia, with comparisons to other Scorpaenidae

“…This range is approximately 5°C warmer than that of native lionfish in our experiments, and 4 to 8°C higher than the values listed for other Indo-Pacific fishes. One explanation for the high preferred temperature may be the shuttlebox technology used in the experiments of Barker (2015), which can be prone to acclimation overshoot in trials lasting less than 4 d (Reynolds 1978). Life stage could also play a role.…”

A study of some factors affecting rates of oxygen consumption of plaice, Pleuronectes platessa L.

“…When fish are exposed to gradually increasing or decreasing temperatures they may show some acclimation response and recent evidence (Reynolds, 1978) suggests that acclimation to increasing temperatures occurs more rapidly than to decreasing temperatures. In addition, the relatively long period (four days) the fish were held under the test conditions could lead to changes in oxygen uptake induced by food deprivation.…”