The temperature preference of the three-spined stickleback,Gasterosteus aculeatusL. (Pisces), collected at different seasons

Thermal preferences were determined, at different seasons, in an aquarium with stable vertical gradients. The temperature preference was found similar for fish collected in April, June, August, and October, despite different acclimation temperatures and length of acclimation period. Both 0-group and 1-group or older fish chose temperatures less than 11°C, and in most cases preferred temperatures between 4 and 8° G, which was lower than the in situ temperatures most of the year. The results suggest that the temperature preference of stickleback from Oslofjorden may be genetically determined.