Order: Cetacea

Family: Delphinidae

Size: Length 6.7 to 11.6 ft (2- 3.5 m)

Weight: 330 to 510 lb (150- 230 kg)

Key Features: Large animal with stout body has a long slender beak with a slight melon on the forehead; rounded flippers. Small but prominent dorsal fin is placed on a hump in the middle of the back. This platform for the fin is distinctive but is not found on all animals outside the Indian region. Marked keels present above and below the tail stock and a distinct notch between the tail flukes. Colour of the species is highly variable but specimens off India are reported to be solid lead grey. There may be 29 to 38 pairs of teeth in each jaw.

Voice: clicks, burst pulses and whistles.

Breeding: Single calf born every 3 yrs after gestation period of 11 months. Weaned at 3 yrs; females sexually mature at 10 yrs, males at 13 yrs. May live up to 40 yrs in the wild

Diet: Fish, molluscs and crustacean

Habitat: This species prefers to feed close to the shore and in tidal creeks. Sometimes it may enter rivers and estuaries. Usually found in sheltered coastal waters including mangrove swamps.

Habits: Species surface to breathe in a very distinctive way in which the beak emerges from the water first and then the melon and hump. As it breathes, the animal cruises with the beak just on the water surface. Sometimes the head is lifted clear of the water and the hump and fin are then clearly visible. Finally the dolphin rolls with its head going down and the hump emerging more, before sliding out of view. They can also heave themselves over mud banks to get from one channel of water to another. They are also known to help Mauritanian fishermen in catching mullet.

Conservation Status: The species is listed as ‘near threatened ‘globally on IUCN red list.

Distribution in Gujarat: Known to caught in fishermen’s nets Indo pacific Hump-back Dolphin have been recorded by ZSI and has also been seen frequenting areas of Gulf of Kachchh and South Gujarat coast near Tithal. As per one survey conducted in 2004, 34 individuals excluding one dead species were recorded around Chusna island and south of Jodiya in Gulf of Kachchh.

 

 

 

 

 

References:

• "Gulf of Kachchh favourite dolphin playground”. Times of India, Ahmedabad. http://articles.timesofindia.indiatimes.com/2009-10-06/ahmedabad/28090512_1_national-aquatic-animal-dolphins-hs-singh

• “After Narmada estuary, more dolphins seen on south Gujarat coast near Tithal”. The Indian Express, Ahmedabad. http://www.indianexpress.com/news/after-narmada-estuary-more-dolphins-seen-on-south-gujarat-coast-near-tithal/543037/2

• Sutaria, D., Jefferson, T. A. (2004). Records of Indo-Pacific Humpback Dolphins (Sousa chinensis, Osbeck, 1765) Along the Coasts of India and Sri Lanka: An Overview. Aquatic Mammals 30(1). Pp: 128-129

• Marine Mammals Facts Courtesy: Animal Fact Files- Mammals. The Brown Reference Group Plc.