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Common Porpoises
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Common Name: Common Porpoises
Class: Mammalia
Order: Cetacea
Suborder: Odontoceti
Family: Phocoenidae
Genus: Phocoena
Species: Four species:
Spectacled porpoise Phocoena dioptrica
Harbor porpoise Phocoena phocoena
Vaquita or Gulf porpoise Phocoena sinus
Burmeister's porpoise Phocoena spinipinnis
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Genus: Phocoena
The porpoises of the genus Phocoena belong to the Mammalian Order
Cetacea, in the suborder Odontoceti. All toothed whales belong to
the suborder Odontoceti, which is Latin for "toothed whales". These
porpoises belong to the porpoise family, Phocoenidae. Other members
of this family include the finless porpoise and Dall's porpoise. The
generic name, Phocoena, is from the Greek phokaina, which means
"porpoise". Some scientists place the spectacled porpoise in a
separate genus, Australophocaena, based on a variety of skeletal
differences. One such skeletal difference is the presence of more
vertebra in the spectacled porpoise than the other species in
Phocoena.
Members of this genus are among the smallest cetaceans. With the
exception of the spectacled porpoise, most prefer coastal waters.
Groups of 5-10 individuals are not uncommon for all species. Prey
species include herring, pollack, mackerel, cod, and sardines.
Lifespan is short, usually 8-10 years.
Spectacled porpoise Phocoena dioptrica
The specific name, dioptrica, refers to the distinctive eye rings of
this species. The spectacled porpoise is black dorsally and white
both laterally and ventrally. The dorsal fin is not pointed, similar
to dorsal fins of dolphins in the genus Cephalorhynchus. Adults
reach 4-6ft in length. Spectacled porpoise prefer the coastal waters
of the southern tip of South America and the cool Antarctic waters.
The biology and behavior of this species are not well known.
Harbor porpoise Phocoena phocoena
The specific name, phocoena, is Greek for "porpoise". The harbor
porpoise lives in the coastal waters of the Northern Hemisphere. The
harbor porpoise is dark gray or black dorsally, with a lighter
underside. Adults grow to about five feet in length and weigh
100-145lbs. Gestation last 10-11 months. Newborn calves are 2-3ft in
length and weigh 15-20lbs.
Vaquita or Gulf porpoise Phocoena sinus
The specific name, sinus, is Latin for "hollow cavity". This may
describe a characteristic of the porpoise's skull. The common name,
vaquita, means "little cow" in Spanish. The vaquita has a very small
range, comprising only the Gulf of California. This species is gray
dorsally with a lighter underside. Adults grow to about five feet in
length, weighing about 110lbs.
Burmeister's porpoise Phocoena spinipinnis
The specific name, spinipinnis, is derived from the Latin spina,
meaning "spike", and pinna, meaning "fin". The term "spike-finned"
is referring to the porpoise's . The common name is named for Dr.
Herman Karl Konrad Burmeister (1807-1892), a Director of the
Zoological Museum at Halle University in Germany. This species'
primary range includes the coastal waters of South America. This
species is gray dorsally, with a lighter underside. Its dorsal fin
sits farther back on its body than other dolphin and porpoise
species, and is pointed towards the flukes. Adults grow 5-6 feet in
length and weigh 125-175lbs.
Conservation
Of the Phocoena species, the harbor porpoise is the most widespread
and least threatened. Very little data exists on the spectacled
porpoise. All species accidentally drown from fishing nets. The
vaquita is critically endangered, and only 100-300 individuals are
estimated to remain in the Gulf of California. The region is now
protected by the Mexican government.
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