Cetacea Cetacea Cetacea () is a widely distributed and diverse clade of aquatic mammals that today consists of whales, dolphins, and porpoises. Cetaceans are carnivorous and finned. Most species live in the sea, some in rivers. The name is derived from the Latin "cetus" "whale", itself from the Greek κῆτος "kētos" "huge fish". There are around 89 extant species, which are divided into two groups or parvorders, the Odontoceti or toothed whales, a group of more than 70 species that includes the dolphins, porpoises, belugas, narwhals, sperm and beaked whales, and the Mysticeti or baleen whales, of which there are now
Strap-toothed whale individual was seen breaching between the South Orkney Islands and South Georgia. Strap-toothed whales' diet consists primarily of squid, although research has suggested that a small portion of their diet may also consist of fish or crustaceans. Adult males have a gape half the size of females and juveniles, limiting their squid to those weighing and less. Nothing is known about social organization of this species. This species has never been hunted or entangled in fishing gear. It is believed to be in a rather safe position compared with other mesoplodonts. Layard's beaked whale is included in the Memorandum of