Balancing requirements for stability and maneuverability in cetaceans.

The morphological designs of animals represent a balance between stability for efficient locomotion and instability associated with maneuverability. Morphologies that deviate from designs associated with stability are highly maneuverable. Major features affecting maneuverability are positions of control surfaces and flexibility of the body. Within odontocete cetaceans (i.e., toothed whales), variation in body design affects stability and turning performance. Position of control surfaces (i.e., flippers, fin, flukes, peduncle) provides a generally stable design with respect to an arrow model. Destabilizing forces generated during swimming are balanced by dynamic stabilization due to the phase relationships of various body components. Cetaceans with flexible bodies and mobile flippers are able to turn tightly at low turning rates, whereas fast-swimming cetaceans with less flexibility and relatively immobile flippers sacrifice small turn radii for higher turning rates. In cetaceans, body and control surface mobility and placement appear to be associated with prey type and habitat. Flexibility and slow, precise maneuvering are found in cetaceans that inhabit more complex habitats, whereas high-speed maneuvers are used by cetaceans in the pelagic environment.