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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Mammalia -> Order Cetacea -> Suborder Odontoceti -> Family Delphinidae -> Species Cephalorhynchus eutropia

Cephalorhynchus eutropia
black dolphin



2008/10/05 03:03:37.774 GMT-4

By Barbara Lundrigan and Liz Aubrey

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Cetacea
Suborder: Odontoceti
Family: Delphinidae
Genus: Cephalorhynchus
Species: Cephalorhynchus eutropia

Geographic Range

Found off the coast of Chile and as far South as the Tierra del Fuego. Found in areas of strong tidal flow above a steeply dropping continental shelf. Found in the coastal waters between Valpariaiso and Navarino Island (north of Cape Horn).

Biogeographic Regions:
pacific ocean (native ).

Habitat

They like shallow, muddy, and turbid waters. They are known to ascend rivers.

Aquatic Biomes:
coastal .

Physical Description

Mass
26 to 74 kg; avg. 50 kg
(57.2 to 162.8 lbs; avg. 110 lbs)


These dolphins have no beak. These dolphins have lots of teeth; 24 to 31 on each side of each jaw. The female is slightly larger than the male, so there is slight sexual dimorphism. They are called the black dolphin because the head, pectoral and dorsal fins, tail, and the posterior of back are all black. The belly, chin, sides, and anterior of the back are all white. The head and body length is 80-110 cm. The length of the pectoral fin is 15-30 cm. The width of the tail fluke is 30-40 cm.

Its rounded dorsal fin, 10-15 cm, distinguishes it from Burmeister's porpoise, which has a triangular dorsal fin with pointed tip and anterior knobs.

Some key physical features:
endothermic ; bilateral symmetry .

Reproduction

Breeding interval
Females generally have one calf about every two years.

Breeding season
These dolphins mate in the early winter.

Number of offspring
1 (average)

They mate as normal dolphins do in the early winter and they bear their young in the spring. Females generally have one calf about every two years. The lifespan of dolphins typically ranges from 25 to 65 years, it is not known whether these are typical.

Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .

Behavior

This is a very shy species, found along coasts in groups of 8 to 14 individuals. There are some reports of aggregations of 20-50. They use echolocation. There are three sounds that they make: slow clicks, fast clicks, and cries.

Key behaviors:
natatorial ; motile ; social .

Food Habits

These dolphins feed on the sea bottom. They eat fish, squid, and crustaceans. They are able to eat solid food by six months of age.

Primary Diet:
carnivore (piscivore ).

Animal Foods:
fish; mollusks; aquatic crustaceans.

Economic Importance for Humans: Positive

This dolphin is moderately exploited for bait in the northern part of its range. In the western region of its range it may be exploited for crab bait. It may also be eaten by humans.

Conservation Status

IUCN Red List: [link]:
Data Deficient.

US Federal List: [link]:
No special status.

CITES: [link]:
Appendix II.

These dolphins are accidentally taken in gill nets.

Other Comments

Much is still to be learned about this species.

The name is taken from Greek, with "eu" meaning well or good, and "tropis" or "tropidos" meaning head or keel. This is probably because the skull has a strong keel in the back.

Contributors

Barbara Lundrigan (author), Michigan State University. Liz Aubrey (author), Michigan State University.

References

Leatherwood, S., R. Reeves. 1983. The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books.

Nowak, R. 1991. Walker's Mammals of One World. 5th ed., Vol. II. Baltimore: The Johns Hopkins University Press.

Wilson, D., D. Reeder, eds.. 1993. Mammal Species of the World; a taxonomic and geographic reference. 2nd ed.. Washington: Smithsonian Institution Press.

2008/10/05 03:03:38.890 GMT-4

To cite this page: Lundrigan, B. and L. Aubrey. 2000. "Cephalorhynchus eutropia" (On-line), Animal Diversity Web. Accessed October 12, 2008 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Cephalorhynchus_eutropia.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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