Physeter macrocephalus - Sperm whale:

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Summary Information
Living Organisms / Animalia / Craniata / Mammalia / Cetacea / Physeteridae / Physeter / Species
Alternative Names
  • Physeter catodon Linnaeus, 1758; Orkney
Description Large toothed whale with huge square head (1/4-1/3 of body length), also 2/3 of way along back distinct dorsal hump with "knuckles" along spine caudal to this. (B142)


  • Male:45-70 tonnes (B142).
  • Female: 15-20 tonnes (B142).


  • 11-15.2m/36-50ft (D23).
  • Female: 11m, rarely 12m; male: 15.8m, rarely to 18m (B142).
  • Neonate:Length about 3.5-4.0m (B142).

External Appearance:

  • Largest toothed whale.
  • Head: large (particularly in adult males), blunt, with single large blowhole at left anterior limit of snout. Lower jaw very narrow and not extending forward to anterior limit of snout. Rami of lower jaw fused along much of length. Dark grey/brownish grey, paler at front of head. Mouth, particularly corners, white-fringed. Short, ill-defined grooves in throat region.
  • Teeth: lower jaw teeth conical, in males large and 20-25 present, in females smaller and fewer. Upper jaw in male up to ten, frequently curved, and virtually concealed beneath gums.
  • Dorsal and flanks dark grey/brownish grey, abdomen paler. Juveniles overall lighter grey. Skin often appears corrugated or shrivelled.
  • Flippers: rounded.
  • Dorsal fin: absent. Two thirds of distance along body triangular/rounded hump present with spinal ridge of "knuckles" caudally behind to tail.
  • Tail: tail stock has keel along underside. Flukes broad, triangular, deeply notched, with straight caudal margin. Black.
  • Numerous scratches and circular scars on head and anterior body.


Range and Habitat World-wide in deep waters, but not found close to ice edge (B142).
  • British & Irish waters: mainly off edge of continental shelf, at least 300kg west of British Isles, or near Shetlands and Orkneys, or west of Ireland.



  • Seasonal migrations, more extensive in males than in females (B142).
  • British & Irish waters: No obvious season to sightings (B142).


  • Tropical waters and to lesser extent temperate waters (B51).
Further Information Food:
  • Squid, mainly medium-sized, particularly from families Onychoteuthidae and Ommastrephidae (B142).
  • Fish, possible more in inshore waters, e.g. Sebastes, Raja, Lophius, Cyclopterus spp.


Feeding Behaviour: --


  • Births mainly July to September
  • Gestation about 16-17 months.
  • Suckling to at least 7.5 years (females), perhaps even 13 years (males).
  • Calving interval probably about 5-6 years (South African populations data)
  • Sexual maturity males 18-19 years, females 7-12 years.
  • (B142).

Breeding Behaviour:

  • Probably males mate with more than one female (B142).


Swim relatively slowly, cruise average about 5-12 km/hour (B142).

Social Behaviour:

  • May be solitary or in groups of up to 50 individuals (B142).

Organisations (UK Contacts):

Electronic Library (further reading):

General Legislation:

Individual techniques:

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