Newly discovered crab lives in the trees

Kani maranjandu (Appukuttannair Biju Kumar/supplied)
Kani maranjandu (Appukuttannair Biju Kumar/supplied)

Hot on the heels of the discovery of a terrifying new venomous spider, along comes a crab that lives high above the ground - in trees.

Kani maranjandu, named after the local tribe that found them, live in a lush biodiversity hotspot in southern India. Maranjandu translates as 'tree crab'.

Strangely for crabs, they live about 10m up, in water-filled hollows. They're shy, scurrying out of sight whenever humans come near.

National University of Singapore biologist Peter Hg told National Geographic it shows how adaptable crabs are.

"The exciting thing for me is that these crabs, regardless of where they have been found, and how they are related (or unrelated) to each other, they have nevertheless evolved to use specialised habitats to enhance their survival - in this case, tree-holes and climbing."

Known species of crabs normally never climb higher than 30cm or so.

Kani maranjandu (Appukuttannair Biju Kumar/supplied)
Kani maranjandu (Appukuttannair Biju Kumar/supplied)

Kani maranjandu only tend to come down when their hollows dry up, but don't go very far - suggesting the smallest impact on the forest could be disastrous for the species.

"This lifestyle of tree living indicates that, since they cannot disperse widely through the sea, their range tends to be limited to a very narrow area," said crab expert Tohru Naruse of Japan's University of the Ryukyus.

The discovery was reported the Journal of Crustacean Biology.