Epidermal Molting in the Bowhead Whale Balaena mysticetus

Abstract

Epidermal molting in the bowhead whales that regularly enter Ulbanskiy Bay of the Sea of Okhotsk in summer has been reported and proven by histological methods. Longitudinal delamination and detachment of thin or thick sheets of a considerable area have been established for the surface layer (stratum externum) of the whale epidermis during molting. A correlation of molting intensity to the level of proliferation and regeneration of all epidermal layers has been noted and assumed to stabilize the thickness of the skin. The phenomenon of molting is discussed from the viewpoint of adaptation of the whales to the conditions of the shallow bays of the Sea of Okhotsk that warm up thoroughly in the summer.