A little-known type of burrowing crayfish thought extinct has been discovered again in Tasmania's rugged west.
The short-tailed rain crayfish was first documented in the 1970s and '80s but not recognised as a unique species until 2006.
It hadn't been sighted for decades until six of the creatures were spotted by environmental scientists in November at two sites in steep, rocky creeks on the slopes of Mount Lyell.
"So little is known about the short-tailed rain crayfish," ECOtas associate professor and crayfish expert Alastair Richardson said.
"It's been difficult to make a determination on its status when for many years we were not even sure it was a separate species.
"But we knew their preferred habitat and remarkably, within just 10 minutes of mooring our boat at our very first target site we found our first specimen.
"We then later discovered a female carrying eggs, which is very encouraging."
The discovery was part of a Hydro Tasmania environmental survey, with the area a known habitat for several endemic crayfish species.
The creeks where the crayfish was found flow into Lake Burbury, which was formed in 1991 as part of the King Hydroelectric Scheme.
"This field work is part of our review of the King and Yolande catchments, which give us a better understanding of the areas we use to generate renewable energy so we can manage them sustainably," Hydro Tasmania environmental scientist Bec Sheldon said.
Australian Associated Press