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Common Name: Bryde's Whale
Class:
Mammalia
Order:
Cetacea
Suborder:
Mysticeti
Family:
Balaenopteridae
Genus:
Balaenoptera
Species:
Balaenoptera edeni |
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Taxonomy/Description
Bryde's whales belong to the
Mammalian Order Cetacea, in the suborder Mysticeti. All baleen
whales belong to the suborder Mysticeti, which is Latin for
"mustached whales". The blue whale belongs to the rorqual family,
Balaenopteridae. The word "rorqual" means "tube whale or furrowed
whale", referring to the pleats on the lower jaws of rorquals. All
rorquals have baleen, a dorsal fin and throat grooves. Other
members of this family include the humpback whale, fin whale, and
minke whale. The blue whale's scientific name is Balaenoptera edeni.
Its generic name, Balaenoptera, means "winged whale", which refers
to the blue whale's dorsal fin. Bryde's whale's specific name,
edeni, means "Eden". The whale's common name, Bryde's, is
pronounced "broodus". The whale was named for Johan Bryde, a
Norwegian whaling pioneer in South Africa. This species was once
classified as two species, Balaenoptera edeni or Eden's whale and
Baleanoptera brydei or Bryde's whale. Once scientists determined
these whales belonged to a single species, the scientific name first
assigned to the species, Balaenoptera edeni, was kept. However, the
common distinction named for Johan Bryde remained. Some scientists
refer to the western Pacific and Indian Ocean populations of Bryde's
whales as Pygmy Bryde's whales, recognized as Balaenoptera edeni.
In 2003, Japanese researchers claimed to have discovered a third
genetically distinct Bryde's whale species, which they named Omura's
whale, Balaenoptera omurai. This species was named for the Japanese
cetologist Hideo Omura.
Bryde's whales and sei whales are
very similar in appearance. Upon closer inspection, Bryde's whales
have three ridges on their head, while sei whales have one ridge.
Bryde's whales may exceed 50ft in length and weigh 13 tons. Female
Sei whales are usually larger than males of the same age. At least
five different distinct populations of Bryde's whale exist. Each
varies in size and color, with some appearing remarkably similar to
sei whales.
Habitat/Diet
Bryde's whales are found in all
oceans, but remain in primarily tropical waters. Bryde's whales are
a predominantly coastal species, although offshore populations are
known to exist. Their major food sources, krill and copepods, live
in all regions. Bryde's whales feed on small fish more often than
other rorquals. As the whale opens its large mouth to gulp up the
prey, the pleats of its lower jaw expand to contain the large volume
of water. The whale then presses its tongue up against the roof of
its mouth, straining the water through its 500-700 baleen plates.
These 16-17 inch plates are composed of keratin, the same substance
of fingernails and hair. The ends of baleen are brush-like,
preventing the prey from escaping. The prey remain inside, and are
consequently swallowed.
Behavior/Reproduction
Bryde's whale leads a solitary life.
However, small groups of 2-3 animals are also commonly observed.
This species does not appear to migrate. The breeding location of
this species is unknown. Gestation lasts about 12 months. Calves
are about 13ft in length, weighing 2,000lbs at birth. They nurse
for six months. Little is known about Bryde's whale breeding and
calving. Males reach sexual maturity at 8-13 years, with females
maturing sexually at 7-10 years.
Conservation
Bryde's whales are slimmer and have less blubber than blue whales,
fin whales and sei whales. Consequently, Bryde's whales were not
hunted until blue whale, fin whale and sei whale populations were
depleted. After the Antarctic sei whale population crash of the
early 1970's, Bryde's whale hunting began. Bryde's whales were
eventually granted protection, with a population of 90,000 animals
remaining from an original population of 100,000. A moratorium on
all whaling has been established, and the greatest
current threat to Bryde's whales is ocean pollution.
