Minke whale each side of their mouths. Most of the length of the back, including dorsal fin and blowholes, appears at once when the whale surfaces to breathe. Minke whales typically live for 30–50 years; in some cases they may live for up to 60 years. Minke whales have a digestive system composed of four compartments with a high density of anaerobic bacteria throughout. The presence of the bacteria suggests minke whales rely on microbial digestion to extract nutrients provided by their food. As with most Mysticetes, the auditory system for the minke whale is not well understood. However, magnetic resonance imaging
Antarctic minke whale dark gray dorsally and clean white (occasionally light gray to gray) ventrally with a thin, dusky margin. Some small, dark gray "speckling" may be present on the body. Antarctic minkes lack the bright white, transverse "flipper band" of the common minke and the white "shoulder blaze" and bright white "flipper patch" (occupying the proximal two-thirds of the flipper) of the dwarf minke. Instead, their narrow, pointed flippers, about one-sixth to one-eighth of the total body length, are normally either a plain light gray with an almost white leading edge and a darker gray trailing edge or two-toned, with a thin