Association of allozymes and temperature in the crested blenny Anoplarchus purpurescens

The crested blenny Anoplarchus purpurescens occurs intertidally in the Puget Sound area (USA), where it is subjected to substantial variation in temperature. A study of a polymorphic esterase in A. purpurescens has revealed a latitudinal cline and a correlation of allelic frequencies with summer water temperature. This finding agrees with previous results for a lactate dehydrogenase polymorphism in A. purpurescens, suggesting a pervasive genetic adaptation to temperature in this species. For each of these enzymes, comparisons within and between two species of Anoplarchus andicate an association between heterozygosity and temporal variability of the thermal environment.