Features of dolphin skin with potential hydrodynamic importance

Abstract

Studies indicating that dolphin skin is sensitive to vibrations or small pressure changes on its surface are reported. They show that the most sensitive areas are located at the angle of gape, and around the eyes, snout, melon, blowhole. The dolphin's nervous system detects changes in pressure on its skin surface; however, the present results only suggest that the dolphin's skin may reduce drag by moving synchronously with small vibrations impinging on its surface. Observations also suggest that the dolphin skin may be able to adjust to pressure changes by amplifying normal microvibrations, or by producing vibrations with muscular contractions. The studies suggest that the skin may actively flex away from higher pressure and toward lower pressure. Cutaneous ridges may play an important role in sensory function and in hydrodynamics.