Sperm Whale - Physeter macrocephalus

Sperm Whale
Physeter macrocephalus

Other Names: Great Sperm Whale, Cachalot, P. catodon

Habitat: Offshore and inshore

Status: Locally common

Population: Unknown

Threats: Human disturbance, entanglement in fishing nets, and pollution

Group Size: 1-50, hundreds may travel together

Fin Position: Far behind center

Newborns: 11 ˝-14 ž ft (3.5-4.5 m), 1 ton

Adults: 36-59 ft 911-18 m), 20-50 tons

Diet: Squid or octopus, and occasionally fish

Teeth: 0 on top row, 36-50 on bottom row

Description

Dorsal fin:

- triangular or rounded hump

Flukes:

- flukes lifted high into air when diving
- broad, triangular flukes
- straight trailing edges frequently notched or frayed

Flippers:

- short, stubby flippers

Teeth:

- thick, conical teeth grow to 8 in (20 cm) long and may weigh over 2 ź lb.(1 kg)
- females have fewer, smaller teeth

Head-on View:

- large head contains spermaceti organ
- snout conceals lower jaw
- huge, square head

Skull:

- asymmetrical skull
- flat, wide upper jaw
- upper jaw has small vestigial teeth that rarely break through gums
- long, narrow lower jaw

Other characteristics:

- slightly raised, slit-like blowhole on left side near front of head
- head proportionally larger in males than females
- small inconspicuous eyes
- older males may be badly scarred, especially around head
- "knuckles" between hump and flukes
- uniform purplish brown to dark gray body color (paler in calves)
- wrinkled, prune-like skin
- thick keel along underside of tail stock
- gray or off-white underside; area may increase with age
- large, squarish head, sometimes with gray or off-white area
- lower jaw broadly visible when mouth closed
- blunt snout may extend up to 5 ft (1.5 m) beyond the tip of lower jaw

Behavior

- can remain submerged for over 2 hours, but typical dive time is less than 45 minutes
- interval between dives may be up to an hour, but usually 5 to 15 minutes
- breaths at regular 12- to 20-second intervals
- whaler's rule of thumb generally works well: for every foot (30 cm) of its length, the Sperm Whale will breathe once at the surface and spend about 1 minute underwater during the next dive
- often surfaces near the same place
- after a long dive, first exhalation is often strong and loud
- when at the surface, usually almost motionless, but may swim leisurely
- frequently breaches and lobtails
- sometimes strands

Distribution

- widely distributed in deep waters worldwide, both offshore and inshore
- tends to be most abundant in certain areas only
- usually found offshore, but may occur inshore where water is more than 655 ft (200 m) deep
- most common in submarine canyons at the edge of the continental shelf
- there is general movement toward the poles in summer: older males migrate as far as the edges of polar ice, but females and juveniles rarely venture beyond 45° N or 42° S
- winter is spent in temperate and tropical waters
- some populations are resident year-round

e-mail questions, comments, and/or suggestions to
wcrc@sci.tamucc.edu

Internet Coordinator: Candice Orca Mottet

e-mail questions, comments, and/or suggestions to wcrc@sci.tamucc.edu

e-mail questions, comments, and/or suggestions to
wcrc@sci.tamucc.edu