Layering and tissue composition in the blubber of the northwest Atlantic sei whale (Balaenoptera borealis)

Abstract

Sei whale and fin whale blubbers are infiltrated by increasing amounts of connective tissue fibers with depth from the epidermis, However, the blubber of sei whales differs from that of fin whales in that it is also interrupted by a definite layer of collagenous and elastic fibers, which in the dorsal blubber is well separated from the muscle proper, but which in the lateral and ventral blubber is progressively closer to the muscle. The layers are discussed in terms of neonatal development and of fat turnover in the adult.