Baleen whales

suborder: Mysticeti (Greek, mystax - moustache; ketos - whale),

These whales have evolved with baleen plates instead of teeth. The plates line the jaw and grow downward like a tooth, but have a composition similar to fingernails, with a brush-like growth on the inner edge. The tangled mass of these hairs acts as a filter during food gathering.

The prey for these whales can be anything from plankton to small schooling fish, depending on the species of baleen whale and the availability of food. The rorqual whales feed by trapping enormous mouthfuls of water and food, they then expel the water out through the baleen filters. In this way the food is retained.

Baleen whales have a pair of nostrils as opposed to a single blowhole. Several other skeletal differences separate them from their 'toothed' relatives.