Latin name

Sousa sahulensis

Other names

Sousa sahulensis

Identification

Australian humpbacks differ slightly from the other three humpback dolphin species in overall length, number of teeth, vertebrae and geographic distribution.

Features of fish fins

The dorsal fin of the Australian humpback dolphin is lower and wider than that of the Atlantic humpback dolphin and the Indian Ocean humpback dolphin, and is dark grey in colour, whereas that of its closest relative, the baiji, is distinctly white (often with a pink tinge). The dorsal fin is short and triangular in shape, with no dorsal "hump".

Fish colouring

The Australian humpback dolphin has a distinctive dark cape-like feature on its back. The body is mostly dark grey with light grey flanks. A diagonal band running just above the eyes and down the neck to the urogenital area separates the dark back from the lighter belly. White scars and dark spots on the head, back, dorsal fin and base of the tail are characteristic of adults. 

Distribution

The species name sahulensis is derived from the Sahul Shelf, which lies between northern Australia and southern New Guinea and is home to Australian humpback dolphins.

Habitat

They're coastal dolphins.

Size

Known dolphin sizes range from 31/2 to 9 feet (1-2.7 m). Birth weights range from 40-50 kg (88-110 lb) and adult weights range from 230-250 kg (507-550 lb).

Behavior

Sometimes these marine mammals can be seen herding fish into shallow water and diving ashore to catch their prey.

These dolphins have been observed mating with the Australian snubfin dolphin.

Food and feeding habits

Feeds on a wide range of coastal, estuarine and nearshore reef fishes. Feeding can occur in a variety of habitats (mangroves, sandy estuaries, seagrass beds and inshore coral reefs).

Reproduction

Mating and births occur throughout the year. Gestation lasts 10-12 months, lactation can last more than 2 years, and the interval between births can be 3 years. Individuals can live to be at least 30 years old. 

Fishing

The species is not interesting for fishing.

Relationship with a person

They tend to be shy and elusive, keeping their distance from people and boats.