Dolphin

Dolphins are aquatic mammals related to whales and porpoises. The name is from Ancient Greek δελφίς delphis meaning "with a womb", viz. "a 'fish' with a womb". more...

The word is used in a few different ways. It can mean:

1. Any member of the family Delphinidae (oceanic dolphins),
2. Any member of the families Delphinidae and Platanistoidea (oceanic and river dolphins),
3. Any member of the suborder Odontoceti (toothed whales; these include the above families and some others),
4. Used casually as a synonym for Bottlenose Dolphin, the most common and familiar species of dolphin.

In this article, the second definition is used.

Porpoises (suborder Odontoceti, family Phocoenidae) are thus not dolphins in our sense. Orcas and some related species belong to the Delphinidae family and therefore qualify as dolphins, even though they are called whales in common language.

There are almost 40 species of dolphin in 17 genera. They vary in size from 1.2 m (4 ft) and 40 kg (88 lb) (Maui's Dolphin), up to 9.5 m (30 ft) and 10 tonnes (the Orca). Most species weigh about 50 to 200 kg (110 to 440 lb). They are found worldwide, mostly in the shallower seas of the continental shelves, and all are carnivores, mostly eating fish and squid.

The family Delphinidae is the largest in the Cetacea, and relatively recent: dolphins evolved about 10 million years ago, during the Miocene.

Taxonomy

• Suborder Odontoceti, toothed whales
  • Family Delphinidae, oceanic Dolphins
    • Genus Delphinus
      • Long-Beaked Common Dolphin, Delphinus capensis
      • Short-Beaked Common Dolphin, Delphinus delphis
    • Genus Tursiops
      • Bottlenose Dolphin, Tursiops truncatus
    • Genus Lissodelphis
      • Northern Rightwhale Dolphin, Lissodelphis borealis
      • Southern Rightwhale Dolphin, Lissiodelphis peronii
    • Genus Sotalia
      • Tucuxi, Sotalia fluviatilis
    • Genus Sousa
      • Indo-Pacific Hump-backed Dolphin, Sousa chinensis
        • Chinese White Dolphin (the Chinese variant), Sousa chinensis chinensis
      • Atlantic Humpbacked 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 Cephalorynchus
      • 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 Lagenorhyncus
      • 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
      • Australian Snubfin Dolphin, Orcaella heinsohni
      • Irrawaddy Dolphin, Orcaella brevirostris
    • Genus Peponocephalia
      • Melon-headed Whale, Peponocephalia electra
    • Genus Orcinus
      • Killer Whale, Orcinus orca
    • 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
  • Family Platanistoidea, River Dolphins
    • Genus Inia
      • Boto (Amazon River Dolphin), Inia geoffrensis
    • Genus Lipotes
      • Chinese River Dolphin (Baiji), Lipotes vexillife
    • Genus Platanista
      • Ganges River Dolphin, Platanista gangetica
      • Indus River Dolphin, Platanista minor
    • Genus Pontoporia
      • La Plata Dolphin (Franciscana), Pontoporia blainvillei

Six animals in the family Delphinidae are commonly called "whales" but are strictly speaking dolphins. They are sometimes called "blackfish":

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