Common Name: Sperm Whale
whales belong to the Mammalian Order Cetacea, in the suborder
Odontoceti. All toothed whales belong to the suborder Odontoceti,
which is Latin for "toothed whales". The sperm whale belongs to the
sperm whale family, Physeteridae. The other members of this family
are the pygmy sperm whale and the dwarf sperm whale. The sperm
whale's scientific name is Physeter macrocephalus. The
generic name, Physeter, means "blow pipe". The specific
name, macrocephalus, means "large head". Recent analysis of
sperm whale DNA has lead some researchers to believe that sperm
whales are more closely related to baleen whales, of the suborder
Mysticeti, than to toothed whales, of the suborder Odontoceti. The
anatomy of the sperm whale is very recognizable. A single blowhole
is located on the left side of the head. Due to the position of the
blowhole, the spout is unmistakable. The spout is characterized by
a forward burst of mist at a 45 degree angle. Another interesting
anatomical quality of sperm whales are their taste receptors. They
have taste receptors throughout their mouth, which probably aid in
detecting changes in water salinity. Largest of the toothed whales,
male sperm whales grow to lengths of 68ft or more, and weigh up to
70 tons. Females are smaller, reaching about 39ft in length and
weighing up to 20 tons.
sperm whale is found in all oceans. Females and juveniles remain in
more temperate waters surrounding the equator, while males journey
to the polar regions. Two separate breeding stocks are believed to
exist, a northern hemisphere stock and a southern hemisphere stock.
Sperm whales dive deep for their prey. Feeding primarily on squid
and other deep ocean creatures, sperm whales dive to depths of
1,200m. Echolocation is used to locate prey in these deep waters
with very little light. Some species of potential prey are octopus,
fish, shrimp, and crabs. Non-food objects found in sperm whale
stomachs include stones and tin cans. The presence of such items
imply that sperm whales dive into the seabed to obtain prey.
sperm whale is well adapted for deep-diving. Sperm whale muscle
absorbs up to 50 percent of the total oxygen store. This muscle
absorption is double the efficiency of terrestrial mammals, and
significantly greater than even baleen whales and seals. Another
adaptation for deep diving lies with the function of the large
spermaceti organ. Unique to sperm whales, the spermaceti organ is
believed to play a very important role in deep diving. It is
hypothesized that the density of the spermaceti organ changes as the
whale's depth changes. As the whale dives, the spermaceti wax cools
from the flow of water over the whale's nasal passages and sinuses.
The density of the wax increases, adding weight to the head which
assists descent. When resurfacing, the blood flow in the
capillaries of the head increases, warming the wax. The sperm
whale's head becomes more buoyant, which assists in the ascent.
Such an adaptation allows the whale to rise to the surface for air
with little effort, which is especially useful after an exhaustive
dive and hunt in the deep ocean.
whales are social mammals. They form pods of up to 100
individuals. The average pod size for coastal whales is 20 whales,
and 3-7 for open ocean whales. During breeding season, males join
with nursery school pods of juveniles and adult females. These
harem schools are facilitated by the single bull whale. Fighting
with other males for the control of the harem is not uncommon. The
adult males use head-butting and biting to fend off competitors.
Peak breeding season occurs in December for the southern stock, and
six months later for the northern stock. Calves are born 14-15
months later. They remain in the nursery school for two years,
continuing to suckle. Suckling may even occur for several years
after weaning. Females reach sexual maturity at 7-12 years.
Puberty is extended in males, beginning at about 9-11 years, with
full sexual maturity at 18-19 years. A growth spurt occurs at the
end of puberty. However, males do not reach social maturity until
about 26 years.
whales are very protective. In fact, such a quality was very
dangerous during the time sperm whales were hunted. Once a whale is
injured, the other members of the pod will circle the dying animal.
The group of whales provide support for the whale, stabilizing its
position with their heads. This formation is called the "marguerite
flower". It was a very dangerous position because it allowed
whalers to systematically harpoon each whale.
Sperm whales were the
primary targets of New England whalers during the 18th and 19th
centuries. The whales were mainly hunted for sperm oil. The oil
was taken from blubber, and whale flesh was sold for human
consumption. Two other products, unique to sperm whales are also
valued. Spermaceti oil is used as an industrial lubricant. It is
very effective, and is even used in space research. "Ambergis" is
the other popular sperm whale derivative. This substance is used as
a fixative in perfumes and cosmetics. Taken from the intestine,
ambergis is believed to be a form of excrement.
Whaling Commission decided to end sperm whaling in 1985. The
original stocks of the southern hemisphere numbered 170,000 males,
and 160,000 females. They have since been reduced to about 71,000
males 125,000 females. Extinction seems highly unlikely for the
sperm whale, given its protection and population size.