Indo-Pacific Humpback Dolphin

An adult Indo-Pacific humpback dolphin is grey, white or pink and may appear as an albino dolphin to some. Populations along the coasts of China and Thailand have been observed with pink skin. The pink colour originates not from a pigment, but from blood vessels which were overdeveloped for thermoregulation. The body length is 2 to 3.5 m (6 ft 7 in to 11 ft 6 in) for adults, 1 m (3 ft 3 in) for infants. An adult weighs 150 to 230 kg (330 to 510 lb). Indo-Pacific humpback dolphins live up to 40 years, as determined by the analysis of their teeth.

Calves are dark grey or black at birth and measure around 1 m (3.3 ft) in length. Their coloration lightens through a mottled grey as they age.

In Hong Kong, boat trips to visit the Indo-Pacific humpback dolphins have been running since the 1990s. The dolphins mainly live in the waters of Lantau North, Southeast Lantau, the Soko Islands and Peng Chau. A code of conduct regulates dolphin-watching activity in Hong Kong waters.

There have been some reports of dolphin watching practices that have further endangered the Indo-Pacific humpback dolphins, such as in Sanniang Bay dolphin sanctuary in Qinzhou and off Xiamen. However, these generally are small, locally organised one-off tours or private pleasure boats that do not adhere to the Hong Kong Agricultural and Fisheries Department's voluntary code of conduct.

Indo-Pacific humpback dolphins live in small groups, generally with fewer than ten individuals. They hunt as a group using echolocation.

Adult dolphins come to the water surface to breathe for 20 to 30 seconds before diving deep again, for two to eight minutes. Dolphin calves, with smaller lung capacities, surface twice as often as adults, staying underwater for one to three minutes. Adult dolphins rarely stay under water for more than four minutes.

They sometimes leap completely out of the water. They may also rise up vertically from the water, exposing the dorsal half of their bodies. A pair of protruding eyes allows them to see clearly in both air and water.

Female dolphins reach sexual maturity at around ten years old, while males mature at around 13 years old. They usually mate from the end of summer to autumn, and calves are born after a gestation period of eleven months. The mother stays with her calf until it can find food for itself, usually when it reaches 3–4 years old.

The Indo-Pacific humpback dolphin is threatened by habitat loss, water pollution, coastal development, overfishing and an increase in marine traffic within its range.

In 2015, the Indo-Pacific humpback dolphin was classed as "vulnerable" on the IUCN Red List of Threatened Species.