Dwarf Sperm Whale – Kogia sima
The Dwarf Sperm Whale belongs to the family of the Sperm Whales and is therefore part of the infraorder of the whales (Cetaceans). Kogia sima was first described by Owen in 1866. In many sources it can be found under the scientific name Kogia simus. However, according to Worms and IUCN Redlist, the current correct name is Kogia sima.
Together with the Pygmy Sperm Whale (Kogia breviceps) it forms the genus Kogia.
Description, Anatomy & Characteristics
With a maximum of 2.70m and 272kg, a Dwarf Sperm Whale is somewhat more slender than its nearest relative, the Pygmy Sperm Whale and also represents the smallest species in the family of sperm whales. Despite its smaller size, its fin is larger than that of the Pygmy Sperm Whale.
Kogia sima has a blue-grey back, while the underside is white. On both sides there is a light stripe that begins at the eyes and runs to the flippers. This is also called false gills.
Compared to the other sperm whale species its head is less angular. Its lower jaw is completely toothed with 14 to 26 teeth. In the upper jaw, however, there are no or at most six, stunted teeth.
Habitat, Distribution & Occurrence
Since most data on Kogia sima comes from strandings, little is known about the actual range of the species.
The Dwarf Sperm Whale lives worldwide, in the tropical and temperate zones of all oceans. In the eastern Atlantic Ocean there are strandings from the Spanish coast to the southern tip of Africa, in the Indian Ocean from South Africa, over Indonesia to Australia and in the Pacific Ocean from Australia to Japan.
Kogia sima probably lives closer to the coast than the Pygmy Sperm Whale. Its preferred habitat should be the zone directly outside the continental shelf.
Biology & Feeding
The Dwarf Sperm Whale has an inconspicuous behavior at the surface. There is neither a big blow, nor many water splashes when it dives up or down. In addition, you rarely see it jumping out of the water.
Although it lives mostly solitary, it comes to sightings of schools with at most ten animals.