Agressive little crab that will take on anything that doesn't fight back.

Perisesarma lividum - In mangroves near Cape Tribulation - Photo by Alex Pawlow

They are found in the mangroves between Cairns and Cape Tribulation, and feed on detritus as well as hunting anything that doesn't get out of their way.

Although fairly small, they can be seen by stopping still in the mangroves and waiting for them to start moving. They have very keen eyesight and depth perception so will stay still as you walk past and they are very well camouflaged.