Newly discovered species of spider-like crab can climb trees

10 Apr 2017

Wreckage of a boat at Hauz Khas Lake, Delhi. Image: swapan banik/Shutterstock

A new genus of crab has been discovered in India, which looks more like a tree-climbing creature than an amphibious crustacean.

A crab unlike anything ever discovered has been identified on the beaches of southern India and, as well as scuttling along the beaches and ocean floor, it also climbs trees.

According to National Geographic, a team of researchers from the University of Kerala has detailed findings on the crab dubbed Kani maranjandu, which roams forests known as the Western Ghats.

The entirely new genus and species is notable for its strong resemblance to a spider, with very long legs that have curved and sharp ends to help them climb trees easier.

In a research paper published to the Journal of Crustacean Biology, the crab was tracked for months following sightings by local tribespeople and, with the capture of a few examples, the new species could be identified.

The etymology of its scientific name does not contain any reference to popular culture – unlike some other recent discoveries – rather, it is named after the Kani tribe that discovered it, as well as the colloquial term for a tree crab.

Kani maranjandu

An example of Kani maranjandu. Image: Appukuttannair Biju Kumar

Great insight into crab evolution

Its typical habitat lies within the flooded hollows of trees in the forest, and the creature propels itself underwater by using its pincers to grab onto the tree trunks and fling forward.

When threatened, many of the species’ younger members will scurry up trees as high as 10 metres off the ground.

The crabs can be spotted by the air bubbles emerging from the water in the hollow.

For Peter K L Ng, who helped to classify the species, the crab discovery offers great insight into the evolution of the species in the face of changing habitats.

“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,” he said.

Colm Gorey was a senior journalist with Silicon Republic