See text Oceanic dolphins are the members of the Delphinidae family of cetaceans. These aquatic mammals are related to whales and porpoises.

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 Orca and its relatives, are commonly called whales, rather than dolphins. They are also sometimes collectively known as "blackfish".

The Delphinidae vary in size from 1.2 metres and 40 kg (Heaviside's Dolphin), up to 7 metres and 4.5 tonnes (the Orca). Most species weigh between about 50 and about 200 kg. They are found worldwide, mostly in the shallower seas of the continental shelves, and all are carnivores, mostly taking fish and squid.

Taxonomy

• ORDER CETACEA

• SUBORDER MYSTICETI
  • Family Eschrichtiidae: Gray Whale
  • Family Balaenopteridae: rorquals
  • Family Balaenidae: right whales and Bowhead Whale
  • Family Neobalaenidae: Pygmy Right Whale

• SUBORDER ODONTOCETI
  • Superfamily Platanistoidae: All river dolphins
    • Family Platanistidae: Indus and Ganges river dolphins
    • Family Lipotidae: Baiji (Yangtze River Dolphin)
    • Family Iniidae: Boto (Amazon River Dolphin)
    • Family Pontoporiidae: Franciscana (La Plata Dolphin)
    • Family Delphinidae
      • Genus Peponocephala
        • Melon-headed Whale, Peponocephala electra
      • Genus Orcinus
        • Orca (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
      • Genus Delphinus
        • Long-beaked Common Dolphin, Delphinus capensis
        • Short-beaked Common Dolphin, Delphinus delphis
      • Genus Lissodelphis
        • Northern Rightwhale Dolphin, Lissodelphis borealis
        • Southern Rightwhale Dolphin, Lissodelphis peronii
      • Genus Sotalia
        • Tucuxi, Sotalia fluviatilis
      • Genus Sousa
        • Indo-Pacific Hump-backed Dolphin Sousa 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 Tursiops
        • Bottlenose Dolphin, Tursiops truncatus
      • 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
    • Family Phocoenidae: porpoises
    • Family Monodontidae: Beluga and Narwhal
    • Family Physeteridae: Sperm Whale
    • Family Kogiidae: Pygmy Sperm Whale and Dwarf Sperm Whale
    • Family Ziphiidae: beaked whales