Dusky Dolphin
A Dusky Dolphin
Scientific Classification
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Cetacea
Family Delphinidae

Oceanic dolphins are members of the cetacean family Delphinidae. These marine mammals are related to whales and porpoises. They are found worldwide, mostly in the shallower seas of the continental shelves. As the name implies, these dolphins tend to be found in the open seas, unlike the river dolphins, although a few species such as the Irrawaddy dolphin are coastal or riverine. Six of the larger species in the Delphinidae, the killer whale (orca), pilot (long-finned and short-finned), melon-headed, pygmy killer and false killer whales, are commonly called whales, rather than dolphins; they are also sometimes collectively known as "blackfish".


The Delphinidae are the most diverse of the cetacean families, with numerous variations between species. They range in size from 1.2 metres (3.9 ft) and 40 kilograms (88 lb) (Haviside's dolphin), to 9 metres (30 ft) and 10 tonnes (orca). Most species weigh between approximately 50 and 200 kilograms (110 and 440 lb). They typically have curved dorsal fins, clear 'beaks' at the front of their heads, and forehead melons, although exceptions to all of these rules are found. They have a wide range of colors and patterns. Most delphinids primarily eat fish, along with a smaller number of squid and small crustaceans, but some species specialise in eating squid, or, in the case of the orca, also eat marine mammals and birds. All, however, are purely carnivorous. They typically have between 100 and 200 teeth, although a few species have considerably fewer. Delphinids travel in large pods, which may number a thousand individuals in some species. Each pod forages over a range of a few dozen to a few hundred square miles. Some pods have a loose social structure, with individuals frequently joining or leaving, but others seem to be more permanent, perhaps dominated by a male and a 'harem' of females. Individuals communicate by sound, producing low-frequency whistles, and also produce high-frequency broadband clicks of 80-220 kHz, which are primarily used for echolocation. Gestation lasts from 10 to 12 months, and results in the birth of a single calf.


Family Delphinidae

Genus Peponocephala
 Melon-headed whale, Peponocephala electra
Genus Orcinus
 Killer Whale (orca), Orcinus orca
 Orcinus citoniensis †
Genus Feresa
 Pygmy Killer Whale, Feresa attenuata
Genus Pseudorca
 False Killer Whale, Pseudorca crassidens
Genus Globicephala
 Long-finned Pilot Whale, Globicephala melas
 Short-finned Pilot Whale, Globicephala macrorhynchus
Genus Delphinus
 Long-beaked Common Dolphin, Delphinus capensis
 Short-beaked Common Dolphin, Delphinus delphis
Genus Lissodelphis
 Northern Right Whale Dolphin, Lissodelphis borealis
 Southern Right Whale Dolphin, Lissodelphis peronii
Genus Sotalia
 Tucuxi, Sotalia fluviatilis
 Costero, Sotalia guianensis
Genus Sousa
 Pacific Humpback Dolphin, Sousa chinensis
 Indian Humpback Dolphin, Sousa plumbea
 Atlantic Humpback Dolphin, Sousa teuszii
Genus Stenella
 Atlantic Spotted Dolphin, Stenella frontalis
 Clymene Dolphin, Stenella clymene
 Pantropical spotted dolphin, Stenella attenuata
 Spinner Dolphin, Stenella longirostris
 Striped Dolphin, Stenella coeruleoalba
Genus Steno
 Rough-toothed Dolphin, Steno bredanensis
Genus Tursiops
 Common Bottlenose Dolphin, Tursiops truncatus
 Indo-Pacific Bottlenose Dolphin, Tursiops aduncus
 Burrunan dolphin, Tursiops australis
Genus Cephalorhynchus
 Chilean Dolphin, Cephalorhynchus eutropia
 Commerson's Dolphin, Cephalorhynchus commersonii
 Heaviside's Dolphin, Cephalorhynchus heavisidii
 Hector's Dolphin, Cephalorhynchus hectori
Genus Grampus
 Risso's Dolphin, Grampus griseus
Genus Lagenodelphis
 Fraser's Dolphin, Lagenodelphis hosei
Genus Lagenorhynchus
 Atlantic White-sided Dolphin, Lagenorhynchus acutus
 Dusky Dolphin, Lagenorhynchus obscurus
 Hourglass Dolphin, Lagenorhynchus cruciger
 Pacific White-sided Dolphin, Lagenorhynchus obliquidens
 Peale's Dolphin, Lagenorhynchus australis
 White-beaked Dolphin, Lagenorhynchus albirostris
Genus Orcaella
 Irrawaddy Dolphin, Orcaella brevirostris
 Australian Snubfin Dolphin, Orcaella heinsohni
Genus †Australodelphis
 †Australodelphis mirus
Genus †Etruridelphis
 †Etruridelphis giulii


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