Eyeless cave fish and a frog that carries its offspring on its back are among the new species a team of scientists have discovered in Indonesia's eastern Papua region.
The researchers from the Institute of Research and Development (IRD) in Montpellier, southern France, studied caves, underground rivers and jungles in the remote Lengguru area of New Guinea island.
"In terms of discoveries almost everything remains to be done in this area, which is very difficult to access but which has exceptionally rich biodiversity," IRD scientist Laurent Pouyaud told AFP.
For seven weeks, the team including biologists, paleontologists and archaeologists explored the vast limestone "labyrinth" where species have evolved in isolation for millions of years.
In one previously undocumented cave they found a new species of fish which had developed without eyes or pigmentation.
"This is, to our knowledge, the first cave fish that has been discovered in Papua," Pouyaud said.
The team's archaeologists were "overwhelmed" by cave paintings and tools made of shell which provided further evidence of the ancient migration of people from Asia to the Australian continent some 40,000 years ago, he said.
The research was "the first step" in an ongoing project to study the region's biodiversity in conjunction with the Indonesian maritime affairs ministry and Institute of Sciences.
Papua's biodiversity is at risk from plans to expand plantations and mining operations in the area, Pouyaud said.
Explore further: Ancient Buddhist murals found in Nepal