Comparative morphology of the cottid genus Myoxocephalus based on biochemical characters

Abstract

Specimens of 11 nominal species of the cottid genus Myoxocephalus were subjected to micro starch-gel electrophoretic analyses. Muscle myogens and isozymes of muscle lactic and malic dehydrogenases were examined.No sexual variations were evident in the electropherograms. Geographic variation in myogen characteristics was investigated for three species, two of which were of a homogeneous nature. In the third, M. scorpius, the specimens from Europe differed from all others.The myogen banding patterns were highly species-specific as were the shapes of their densitometer tracings. Two banding patterns were detected in malic dehydrogenase isozymes. Lactic dehydrogenase isozymes also evinced two distinct patterns, 11 species having one pattern and one (M. scorpioides) exhibiting both.On the basis of myogen data two natural groupings are evident, one composed of the Asiatic species and another of the Arctic and American east coast forms.