Bottlenose Dolphins are the most familiar dolphins to most people as they are the most common species to be kept in captivity and to be trained to perform tricks for the amusement of audiences. They are the largest of the beaked dolphins. Their backs and sides are dark gray, usually fading to pale undersides. There is a crease where the rostrum (beak) joins the melon (forehead). Pectoral fins and flukes are pointed at the tips; the dorsal fins curve slightly backwards. Atlantic bottlenose dolphins grow to about 2.8 metres long at maturity, but the Pacific variety may be somewhat larger. They weigh up to about 650 kilograms.
They may be found worldwide in all coastal waters throughout the world, except for the polar seas. They are encountered from coastal and inshore waters to the pelagic waters of the deep oceans. The precise ranges of the various populations of bottlenose dolphins around the world is unclear, especially those who live far from shore. Many seem to prefer a fairly small area within a shallow lagoon or bay. They will move if necessary to find food or to avoid hazards.
Bottlenose dolphins sometimes live to over fifty years old, but most do not reach this age. They do not dive deep compared with many dolphins and rarely go deeper than about 45 meters. Their dives are usually up to about 4 minutes in duration. They typically swim at around 5 – 12 kilometres per hour but can travel at over 25 kilometres per hour.
Bottlenose dolphins normally live in pods. Inshore pods are typically composed of up to about twenty-five dolphins, while offshore pods can consist of hundreds of individuals. Solitary individuals are sometimes seen in the wild, but it is unusual. Sometimes, smaller pods may join into larger groups, presumably for hunting purposes. Bottlenose dolphins also have also been observed swimming with other cetaceans such as sperm whales or right whales.
Many scientists currently recognise two species of bottlenose dolphin: the common bottlenose dolphin, Tursiops truncatus, and the Indo-Pacific bottlenose dolphin, Tursiops aduncus.