Australian Snubfin Dolphin

A species of delphinid in the genus, Orcaella, which contains one other species, the Irrawaddy dolphin Orcaella brevirostris, O. heinsohni females can reach lengths of 230 cm (91 in) and males can reach 270 cm (110 in). Australian snubfin dolphins are subtly tricoloured: brownish on the top, lighter brown along the sides, and a white belly; the Irrawaddy dolphin, on the other hand, is uniformly slate grey except for the white belly. The new species has a rounded forehead, very unlike other dolphin species in Australia, and the very small, "snubby" dorsal fin distinguishes it from other dolphins in its range. The lack of a groove on each side of the back and the presence of a neck crease further distinguishes this species from its relative. Tail flukes also have an identifiable jagged trailing edge that can help distinguish it from other species of delphinids.

The snubfin dolphin is considered endemic to Australia. In the Pacific Ocean off Townsville, about 200 individual snubfin dolphins were found. The range of the species is expected to extend to Papua New Guinea; that is, O. heinsohni is endemic to the northern half of the Sahul Shelf, but the majority live in Australian waters. They are found all along the northern coasts of Australia, from Broome, Western Australia, to the Brisbane River in Southeast Queensland. They are not thought to be common, and are being given a high conservation priority. Australian snubfin dolphins are currently listed as "vulnerable" by the IUCN.

Off the coast of Queensland, Australia, the Australian snubfin dolphin predominantly feeds in coastal-estuarine waters. There is a predominance of feeding activity by rivers and areas off the coast of Cleveland bay. Australian snubfin dolphins have also been seen foraging and then following passing by fish trawlers to capitalize on an opportunity for prey. They can be classified as opportunistic feeders and have been seen congregating to feed in groups. Being opportunistic feeders snubfins consume a large array of prey items. Snubfin dolphin consume a wide array of prey, that can be narrowed down to coastal, estuarine, and reef-associated fishes throughout the water column and at the bottom. The most common prey items by species are cardinal fish (Apogon), proceeded by the cuttlefish (Sepia), the squid Uroteuthis (Photololigo), and the toothpony fish (Gazza).

In a study of Australian snubfin dolphins consisting of 18 individuals, it was determined the approximate life span is around 30 years. However, since sightings are so rare, a lot remains unknown about many about this species. Gestation is estimated to be around 11 months based on rates of similar species.

Although some hunting by indigenous people occurs (as evidenced by the 1948 specimen), this is likely to be insignificant compared to other threats such as drowning in sharknets and fishing gear. Snubfins are particularly at risk from incidental capture in gillnets, which are often placed in near-shore areas and near the mouths of rivers, where these dolphins are more likely to be found. Although it is not known how many dolphins die in this manner, it is considered to be the greatest threat to populations in Papua New Guinea. Anti-shark nets and drumlines put in place for Queensland's shark control program are also a significant threat to snubfins, with about 1.8 snubfin dolphins killed every year between 1997 and 2011.