The Indian Ocean bottlenose dolphin is a species of bottlenose dolphin. They are very similar to Common bottlenose dolphins in appearance. Indian Ocean bottlenose dolphins have a more slender body and their beak is longer and more slender. The Indian Ocean population also is somewhat lighter blue in colour. The cape is generally more distinct, with a light spinal blaze extending to below the dorsal fin. The most obvious distinction can be made with the presence of black spots or flecks on the bellies of adults of Indian Ocean bottlenose dolphins, although they are not always present. These black spots are very rare in Common bottlenose dolphins. The teeth can number between 23-29 in each upper and lower jaw, and are more slender than those of Common bottlenose dolphins.
Diurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
A piscivore is a carnivorous animal that eats primarily fish. Piscivorous is equivalent to the Greek-derived word ichthyophagous. Fish were the die...
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract ...
Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
Natatorial animals are those adapted for swimming. Some fish use their pectoral fins as the primary means of locomotion, sometimes termed labriform...
Among animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
Polygynandry is a mating system in which both males and females have multiple mating partners during a breeding season.
A herd is a social grouping of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with...
A dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social gr...
NoNot a migrant
Animals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
Indian ocean bottlenose dolphins are found around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. They live in the warm temperate to tropical waters. These dolphins occur in shallow water near the shore at depths of less than 300 m.
Indian ocean bottlenose dolphins are very social animals. They live in groups that can number in the hundreds, but groups of 5-15 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. Indian ocean bottlenose dolphins located in Shark Bay, Australia, have a symbiotic relationship with sponges. They do "sponging". A dolphin breaks a marine sponge off the sea floor and wears it over its rostrum, apparently to probe substrates for fish, possibly as a tool, or simply for play. These dolphins communicate via auditory perception and via tactile signals. They rub flippers over the flippers or bodies of other dolphins. As their sense of sight is not well-developed, their sense of hearing is very keen. Each dolphin uses a characteristic whistle that helps other dolhins identify them individually.
Indian ocean bottlenose dolphins have polygynandrous (promiscuous) mating system. Males form alliances with 1-3 other unrelated males. These male groups herd females for mating. It's called “mate guarding.” Breeding females also form smaller groups as they are easier to defend. 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 after which only 1 calf is born. The calves are weaned between 1.5-2 years but can remain with their mothers for up to 5 years. The interbirth interval for females is typically 4-6 years. Females reach maturity at 7-12 years of age, males reach reproductive maturity at 9-13 years.
Indian Ocean bottlenose dolphins are not considered to be endangered. Their near-shore distribution, though, makes them vulnerable to environmental degradation, direct exploitation, and problems associated with local fisheries. Large-mesh nets set to protect bathers from sharks in South Africa and Australia have also resulted in a substantial number of deaths. Gillnets are also having an impact, and are a problem throughout most of the species' range.
According to the IUCN Red List, the total population size of the Indian Ocean bottlenose dolphin is unknown. However, there are estimated populations of the species in the following areas: off Zanzibar (Tanzania) - 136-179 dolphins; in the Persian Gulf - 1,200 dolphins; along the rim of the Swatch-of-No-Ground (Bangladesh) - 400 dolphins; off western Kyushu (Japan) - 218 dolphins; off Mikura Island (Japan) - 168 dolphins; northeastern Philippines - 50 dolphins; off Queensland (Eastern Australia) - 1,099 dolphins; in Shark Bay (Western Australia) - 2,000-3,000 dolphins. Currently, Indian Ocean bottlenose dolphins are classified as Data Deficient (DD) on the IUCN Red List.