Thermal Preference of Juvenile Dover Sole (Solea solea) in Relation to Thermal Acclimation and Optimal Growth Temperature

Edward Schram,Hans Van De Vis,Stijn Bierman,Lorna R Teal,Olga Haenen,Adriaan D Rijnsdorp,Carlos A Navas

doi:10.1371/journal.pone.0061357

Abstract

Dover sole (Solea solea) is an obligate ectotherm with a natural thermal habitat ranging from approximately 5 to 27°C. Thermal optima for growth lie in the range of 20 to 25°C. More precise information on thermal optima for growth is needed for cost-effective Dover sole aquaculture. The main objective of this study was to determine the optimal growth temperature of juvenile Dover sole (Solea solea) and in addition to test the hypothesis that the final preferendum equals the optimal growth temperature. Temperature preference was measured in a circular preference chamber for Dover sole acclimated to 18, 22 and 28°C. Optimal growth temperature was measured by rearing Dover sole at 19, 22, 25 and 28°C. The optimal growth temperature resulting from this growth experiment was 22.7°C for Dover sole with a size between 30 to 50 g. The temperature preferred by juvenile Dover sole increases with acclimation temperature and exceeds the optimal temperature for growth. A final preferendum could not be detected. Although a confounding effect of behavioural fever on temperature preference could not be entirely excluded, thermal preference and thermal optima for physiological processes seem to be unrelated in Dover sole.

Highlights

Fish are obligate ectotherms and most, if not all, physiological processes in fish are under the influence of body temperature [1]
Thermoregulatory behaviour During the non-gradient observations fish distribution across the preference chamber was found to be non-random (MANOVA, p = 0.002) for all three treatments (Figs. 4A, 4B, 4C), indicating that in the absence of temperature differences fish show some preference for given areas of the preference chamber
Our observations revealed that thermal preference and thermal optima for physiological processes may be unrelated in Dover sole, making it an interesting model species to further explore the relation between thermoregulatory behaviour and thermal physiology in ectothermic vertebrates

Summary

Introduction

Fish are obligate ectotherms and most, if not all, physiological processes in fish are under the influence of body temperature [1]. Maximum performance of physiological processes occurs at species specific thermal optima. It allows fish to optimize the performance of physiological processes in a heterogeneous thermal environment by thermoregulatory behaviour. Thermoregulatory behaviour is affected by complex trade-offs between internal processes with different thermal optima as well as by external factors such as food availability and predation risk [4]. When exposed to a temperature gradient the thermal preference of fish may initially be under the influence of their previous thermal acclimation (acute preference). Prolonged exposure to a temperature gradient results in fish gravitating to this final preferendum. Acute thermal preference close to the final preferendum independent from thermal acclimation has been reported in fish [5]

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