Dwarf Sperm Whale
The Dwarf Sperm Whale is widely distributed through tropical and temperate seas. Records of sightings are scattered along the American coast of the North Atlantic, the South American and African coasts of the South Atlantic, the Indo-Pacific region and the Pacific ocean as a whole.
Classification: The Dwarf Sperm Whale, Kogia simus, although described by the English anatomist Owen in 1866, was only accepted as a species separate to Kogia breviceps (the Pygmy Sperm Whale) a century later. The scientific name, simus, refers to the snubbed snout.
Local Names: Owen's Pygmy Sperm Whale.
Description: This robust cetacean is the smallest of all whales, and closely resembles the Pygmy Sperm Whale in size, stature and colour. However, the snout of the Dwarf Sperm Whale becomes blunt and square, not rectangular, in adulthood, and the dorsal fin is larger. There are a number of small irregular grooves on the throat behind the mouth. There are between fourteen and twenty-four teeth on the lower jaw, with up to three pairs on the upper. They are dark bluish grey in colour, lightening to a pinkish off-white underneath. Maximum weight is around 210kg, with a maximum length of 2.7m being attained in both sexes.
Recognition at sea: The Dwarf Sperm Whale can be easily confused with the Pygmy Sperm Whale, and other blunt-headed cetaceans (such as Risso's Dolphin, the Pygmy Killer Whale and the Melon-Headed Whale). However, the Dwarf Sperm Whale has a more square-shaped head and moves much slower than the other species of blunt-headed cetacean, and it has a larger dorsal fin than the Pygmy Sperm Whale.
Habitat: Dwarf Sperm Whales are oceanic animals, moving across and over the continental shelf to feed.
Food & Feeding: Like the Pygmy Sperm Whale, this species of cetacean is slow-moving and hunts by stealth, so prey are probably incapable of fast movement - therefore, again like the Pygmy Sperm Whale, the Dwarf Sperm Whale eats small fish, cuttlefish, deepsea shrimps and squid.
Behaviour: Pods contain less than ten animals, mainly females with calves and sexually immature males. The behaviour of the Dwarf Sperm Whale is very similar to that of the Pygmy Sperm Whale. The blow is inconspicuous and low, and after blowing the cetacean simply drops out of sight. It rarely approaches boats, and when startled evacuates a reddish-brown intestinal fluid as a decoy before it dives.
Longevity: Unknown.
Estimated Current Population: Unknown.
The Influence of Man: Small numbers of the Dwarf Sperm Whale were taken by early whalers, and a few have been taken in recent years by Japan and the Caribbean. Again akin to the Pygmy Sperm Whale, larger numbers of this small cetacean are caught in gill-nets.
Source: CETACEA
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