Species: K. simus Owen, 1866
The dwarf sperm whale is smaller than the pygmy sperm whale and exhibits several distinguishing features. The falcate dorsal fin is tall, prominent, and located on the mid-back region. There is a gill-shaped color pattern behind the eyes as with the pygmy sperm whale. The dwarf sperm whale, however, has fewer teeth and two parallel creases under the throat which are not present in the pygmy sperm. It is a very rare animal insofar as confirmed sightings are concerned, and most information comes from infrequent strandings.
Physical Description: Stocky body with a single blowhole located slightly to the left of the forehead. Several short, irregular throat grooves resemble those found among beaked whales.
Color: The dark dorsal side converges to the lighter flanks and ventral side, with a dark, gill-shaped coloration behind each eye.
Fins and Flukes: The high, prominent, falcate dorsal fin is located on the mid-back region. The flippers are rounded at the tips. The flukes are well developed, slightly rounded at the tips, with a definite median notch.
Length and Weight: The dwarf sperm whale reaches 6.75 to 8.75 ft (2.1 to 2.7 m) and 300 to 600 lb (135 to 275 kg).
Teeth: 7 to 13 sharply pointed, backward-curved teeth are found in each side of the lower jaw, fitting into sockets in the upper jaw. Usually there are 1 to 3 rudimentary teeth in each side of the upper jaw.
Feeding: Mostly squid, but fish and crustaceans are also eaten.
Breathing and Diving: Thee animals are known to dive to at least 1,000 ft (300 m). The blow is inconspicuous, and the animal presents less of the body when “logging” on the surface than its cousin the pygmy sperm whale.
Mating and Breeding: The length at birth is about 3.3 ft (1 m) and calves are nursed until more than 5 ft (1.5 m) in length. The gestation period is about 11 months. Females may give birth in successive years.
Herding: They are often seen individually or in groups of less than 10. There may be some segregation by age and sex, similar to that among sperm whales.
Distribution: They are found in seas adjacent to South Africa, India, Sri Lanka, Japan, Baja California, California, and the eastern United States.
Migration: No information available.