Physiological polymorphism of a grass frog population. III. The effect of the season on the phenotypic manifestation of frog polymorphism by the level of muscle tissue thermostability]

A study was made of the phenotypical manifestation of physiological polymorphism of the population of the grass frog by the heat resistance level of m. interphalangealis in different seasons. In autumn (starting from the 2nd half of October), throughout winter, and in summer the polymorphism of frogs is well expressed, whereas in spring (during the reproduction period) and in the first half of October (during the migration of animals to the places of hibernation) the polymorphism appears to be hidden. The latter phenomenon is due to differences in the pattern of individual seasonal changes in the heart resistance of muscles in individuals of different groups.