Indo-Pacific bottlenose dolphin

The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a species of bottlenose dolphin. 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 the Indo-Pacific bottlenose dolphin as "data deficient" in their Red List of endangered species because of this issue.

Indo-Pacific bottlenose dolphin
  • Size

    Size of Indo-Pacific bottlenose dolphins can vary based on geographic location; however, its average length is 2.6 metres (8.5 ft) long, and it weighs up to 230 kilograms (510 lb). The length at birth is between 0.84 and 1.5 metres (2.8 and 4.9 ft).

  • Feeding

    Indo-Pacific bottlenose dolphins feed on a wide variety of fish and cephalopods (particularly squid). The prey items found in the stomach contents included 50 species of bony fish and three species of squid.

  • Life History

    The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions. Gestation period is about 12 months.The calves are weaned between 1.5 and two years, but can remain with their mothers for up to five years.
    The interbirth interval for females is typically four to six years.

  • Behavior

    Indo-Pacific bottlenose dolphins live in groups that can number in the hundreds, but groups of five to 15 dolphins are most common. In some parts of their range, they associate with the common bottlenose dolphin and other dolphin species, such as the humpback dolphin.