Sperm Whale
Family: Physeteridae
Genus: Physeter
Species: Macrocephalus
Also known as cachalot or Spermacet Whale
Distribution:
The Sperm Whale is distributed worldwide in temperate waters. Bull Sperm Whales also appear in polar regions.
Size:
Males can grow up to 70 feet long from head to tail, but females are significantly smaller, up to around 30ft; Males are 45-70 tons in weight; females are 15-20 tons.
Colouring:
Dark gray, with white marks. May also sport circular scarring from giant squid suckers.
Diet:
Mainly - 80 percent - of the Sperm Whale's diet is made up of squid, with the remainder being made up of fish & crustaceans.
Gestation & Longevity:
14-15 months & up to 70 years, respectively.
Immortalised in
Melville's classic (depending on who you talk to ;-)) "
Moby Dick", the Sperm Whale is the largest of all of the toothed whales.
The first thing that you notice about the Sperm Whale is the size of its head in comparison to the rest of its body. Around one third of the body length is accounted for by the head alone.
This vast space is taken up by the
spermaceti organ, a hard, waxy organ that is said to help focus sound used in sonar, as well as an aid to controlling the buoyancy of the whale when diving.
This organ is vital when the Sperm Whale is hunting in the pitch-black of the deep ocean, where echo-location is used to find their prey.
These dives to the ocean floor are possibly the most remarkable of all the Sperm Whale's traits.
Descending at around 500 feet per minute, the whales have been recorded reaching depths of 10,000 feet where they will hunt for anywhere between one and two hours before returning to the surface. Amazingly, it takes only a few minutes before the whale is ready to dive again, and they can perform several of these dives before they reach their physiological limit.
As mentioned above, the Sperm Whale is a very social animal, unlike the rogue bull portrayed in "Moby Dick".
They form different schools depending upon a number of factors, such as age, sex & location. For example, in polar waters, you will only find bull whales, but in warmer climes, as many as five different types of school have been observed, ranging from the so-called "bachelor schools" of young bulls, to "nursery schools" of calves & juveniles, accompanied by mature females.
These schools can vary greatly in size, from as few as 4-5 to as many as 100 animals, and once the bonds within these school are formed, they appear to persist for life - a tagged female was found with the same school ten years after it was first marked.
Unfortunately, these powerful bonds can sometimes do harm to the whales.
When one of their number is injured, the rest of the
pod
will gather around the wounded whale, supporting it & encircling it, in what's dubbed the "marguerite formation".
This defensive stance was recognised & quickly exploited by whalers hunting the Sperm Whale, as it made it remarkably easy to pick off an entire pod with little trouble.
See also...
Cetacean
Pygmy Sperm Whale
Dwarf Sperm Whale
Whale