Dolphins living in Port Philip and the Gippsland Lakes have been declared to be a new species, researchers say.
It is only the third time since the late 19th century that a new dolphin species has been recognised.
The new species will be formally named Tursiops australis.
The dolphins were originally thought to be one of the two already recognised bottlenose dolphin species.
But examination of their skulls and other characteristics led to them being declared a new species.
“We found that the skull morphology and the external morphology and colouration and their genetics is quite distinct,” Monash University PhD student Kate Charlton-Robb said.
“It’s distinct enough from the common bottlenose dolphin that this is actually a new dolphin species.”
Ms Charlton-Robb says there are only about 150 of the dolphins in the region.
“The main focus is obviously the conservation of this new species so we can enjoy them for future generations and be able to continue the research to have a look at these two populations and how they interact with other populations across coastal Victoria, down in Tasmania and into South Australia,” she said.