Indo-Pacific Bottlenose Dolphin

The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a species of bottlenose dolphin. This dolphin grows to 2.6 metres (8.5 ft) long, and weighs up to 230 kilograms (510 lb). It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its belly is lighter grey or nearly white with grey spots.

Until 1998, all bottlenose dolphins were considered members of the single species T. truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. The Indo-Pacific bottlenose dolphin is generally smaller than the common bottlenose dolphin, has a proportionately longer rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin. There is evidence the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the genera Stenella and Delphinus, especially the Atlantic spotted dolphin (S. frontalis), than it is to the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists both species as data deficient in their Red List of endangered species because of this issue.