Pygmy Sperm Whale

Pygmy Sperm Whale, Kogia breviceps, is a distant ‘relative’ of Sperm Whales (Physeter macrocephalus). At sea it is often difficult to distinguish them from the Dwarf Sperm Whale, which only differs in size and shape of the dorsal fin.

CHARACTERISTICS

Latin name : Kogia breviceps
Suborder : Odotonceti
Family: Kogiidae
Length : up to 3.7 meters
Weight : up to 400 kg
Dive time : up to 20 minutes
Dive depth: Depth unknown but estimated up to 1 500 meters
IUCN Status: Data deficient

Worldwide distribution of Pygmy Sperm Whale (Kogia breviceps). Encyclopedia of Marine Mammals IIIrd Ed. Bernd Würsig, I. G. M. Thewissen & KIT M. Kovacs

DESCRIPTION

Color: Black to bluish-grey while its aides are light grey. The ventral part is whitish. A light « false gill » crescent mark may be present between the eye and the flipper.

Head: Square head filled with spermaceti fluid. Pigmy and Dwarf Sperm Whales have the blowhole is on the left side of the tip of the snout, like Sperm Whales.

Fins: Very small hook-shaped dorsal fin. The caudal fin is concave and slightly notched.

Teeth: 9 to 16 pairs of teeth on the lower jaw, and almost always 3 pairs of rudimentary teeth on the upper jaw.

Most of the information available about Pygmy Sperm Whales come from stranding events. In this specimen the teeth on the lower jaw are visible.

LIFE HISTORY

DIET

Pygmy Sperm Whale feed on predominantly on squid but also on bottom fish and crabs.

REPRODUCTION

Sexual maturity is reached at the age of 5 years.The gestation lasts about 9-11 months and can apparently occurs every year, because the nursing lasts one year. At birth, calves measure around 1.2 meter in length. Breeding takes place in the summer while calving occurs in spring.

SOCIAL BEHAVIOR

Pygmy Sperm Whales are usually solitary animals but they can form groups of 4-5 individuals. Usually Pygmy Sperm Whales breathe once and then let itself sink. Typically they are encountered logging motionless at the surface. Unique to the Kogiidae species, appended to the small intestine near the anus, they have a sac filled of a dense red-brown fluid. If the animal is stress it release the reddish fluid to distract the predator.

VOCAL BEHAVIOR

Pygmy Sperm Whales do not seem to be vocal, especially when at the surface. They use the echolocation to hunt their preys during deep dives and here you can listen to a recording of their clicks collected by the University of California San Diego.