New Species of Humpback Dolphin Found in Australian Waters

Marine biologists have discovered a new species of dolphins previously unknown to science in the waters off northern Australia.

A new species of humpback dolphin (known for the peculiar hump below the dorsal fin) was discovered in the Australian waters by a team of researchers working for the Wildlife Conservation Society, the American Museum of Natural History and several other groups. The finding of this new species puts an end to the long standing debate on how many species of humpback dolphins actually exist in the wild.

The discovery of the unnamed dolphin brings the total number of species belonging to the humpback dolphin family to four. The New York based WCS determined the number of distinct species in the family of humpback dolphins by using genetic testing and physical comparison.

The humpback dolphin species mainly consists of the Atlantic humpback and three other species of the Indo-Pacific humpback, in which one is new to science. The researchers plan on further dividing the group into two in which dolphins that occupy the waters off the coast of West Africa and Northern Australia fall into one group and the other group will comprise of the dolphins found in several parts of the India Ocean.

Reports according to Washington Post state that this new discovery will help governments and several conservation groups to create policies tailored for each species. Also this new finding is a critical first step in efforts to conserve the decreasing population of the marine mammal.

"Based on the findings of our combined morphological and genetic analyses, we can suggest that the humpback dolphin genus includes at least four member species," Dr. Martin Mendez, Assistant Director of WCS's Latin America and the Caribbean Program and lead author of the study, said in a statement. "This discovery helps our understanding of the evolutionary history of this group and informs conservation policies to help safeguard each of the species."

Humpback whales that inhabit the coastal waters, deltas, and estuaries and seen throughout the Indian and Pacific oceans to the coast of Australia, are mostly threatened by fishing and habitat loss. Listed as 'Vulnerable' by the IUCN Red List, these charismatic mammals can grow up to 8 feet in length.

The authors propose recognition of at least four species in the humpback dolphin family namely the Atlantic humpback dolphin (Sousa teuszii) that is seen in the eastern Atlantic off West Africa; the Indo-Pacific humpback dolphin (Sousa plumbea), that is found from the central to the western Indian Ocean; another Indo-Pacific humpback dolphin (Sousa chinensis), that is seen in the eastern Indian and western Pacific Oceans; and a fourth Sousa species found off northern Australia, which is yet to be named.

The team also gathered physical evidence from a number of beached dolphins as well as museum specimens. The researchers examined the genetic testing tissue samples of 235 dolphins, in which they looked at both the mitochondrial and nuclear DNA, and also examined the craniums of nearly 180 different dolphins.

"New information about distinct species across the entire range of humpback dolphins will increase the number of recognized species, and provides the needed scientific evidence for management decisions aimed at protecting their unique genetic diversity and associated important habitats," said Dr. Howard Rosenbaum, Director of WCS's Ocean Giants Program and senior author on the paper.

The details of the finding were documented in the journal Molecular Ecology.