Kogia brevicepspygmy sperm whale

Geographic Range

Kogia breviceps is confined to warmer waters (Minasian et al. 1984, Watson 1981).

Habitat

K. breviceps prefer warm tropical waters. They may migrate to more temperate waters in the summer months. They also stay in deep waters (Watson 1981).

Physical Description

K. breviceps is a small whale averaging about 3 meters in length for both sexes. Calves are about 55 kilograms at birth. They have a swollen nose and head, which takes up about 15% of their body length. Their head is conical with a small underslung jaw that opens beneath the upper jaw in a shark-like manner. The flippers are short, broad, and far forward on the body. They have a small curved dorsal fin. K. breviceps is a steely grey color with a distinct pink tinge. In the water they often look purple. They are a paler grey on the belly. Between the eye and the flipper is a small white/pale grey bracket mark. This is often called a "false gill", further attributing to its resemblance to a shark. There is another similar pale spot in front of the eye. Scarring is rare. They have a short rostrum which makes their wide skull triangular. K. breviceps have 12-16 teeth on each side and their blowhole is slightly displaced to the left. These two traits distinguish the pygmy sperm whale, K. breviceps, from the dwarf sperm whale, K. simus (Minasian et al. 1984, Watson 1981).

  • Average mass
    363 kg
    799.56 lb
  • Average mass
    424600 g
    14963.88 oz
    AnAge

Reproduction

Mating usually takes place in the summer. Gestation lasts for about 9 months and the calf is born in the spring. ( http://www.nsrl.ttu.edu/tmot1/kogibrev.htm., Watson 1981).

  • Breeding season
    Mating usually takes place in the summer
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    9 months
  • Average gestation period
    335 days
    AnAge
  • Average weaning age
    12 months

The calf stays with its mother and is nursed for about 12 months. Calves are about 1.2 meters long and about 55 kilograms at birth.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Behavior

Though there are sightings of solitary individuals, most of the whales travel in small pods of 3-6. Like the great sperm whale, Physeter macrocephalus, K. breviceps breaches, landing in the water tail first. Also like the great sperm whale, K. breviceps have spermaceti in their foreheads. This suggests that they have the ability to dive into very deep water and hover motionless at any depth to wait for prey. They have great speed and can stay under water for long periods of time, another reason to suspect very deep dives. K. breviceps is often found stranded. There seems to be a relation between strandings and motherhood, as most strandings are mothers with newborn calves. K. breviceps have been descibed as being very slow and deliberate swimmers while breathing and swimming near the surface ( http://www.nsrl.ttu.edu/tmot1/kogibrev.htm., Minasian et al. 1984, Watson 1981).

Communication and Perception

Food Habits

K. breviceps eat mostly squid, shrimp, fish, and crabs with what seems to be a preference for deepwater foraging (Watson 1981).

  • Animal Foods
  • fish
  • mollusks
  • aquatic crustaceans

Economic Importance for Humans: Positive

There is little economic benefit to humans from K. breviceps. They are relatively uncommon so few are taken by the Japanese and an occasinal one is take by Indonesians ( http://swfsc.ucsd.sars.Pygmy_HI.htm, Watson 1981).

Conservation Status

Not much is known about this species. The infrequency of sightings is often assumed as rareness. It is vulnerable to Hawaiian fisheries and gillnets, float lines, and long lines

( http://swfsc.ucsd.sars.Pygmy_HI.htm, Watson 1981).

Contributors

Barbara Lundrigan (author), Michigan State University, Allison Myers (author), Michigan State University.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

June 30, 1995. "Pygmy Sperm Whale Hawaiian Stock" (On-line). Accessed December 4, 1999 at http://swfsc.ucsd.sars.Pygmy_HI.htm.

1994. "Pygmy Sperm Whale" (On-line). Accessed December 4, 1999 at http://www.nsrl.ttu.edu/tmot1/kogibrev.htm.

Minasian, S., K. Balcomb, III, L. Foster. 1984. The World's Whales. U.S.: The Smithsonian Institution.

Watson, L. 1981. Sea Guide to Whales of the World. London: Hutchinson and Co..