The new species of crab has been named Lamarckdromia beagle (after the ship HMS Beagle that took naturalist Charles Darwin around the world) and belongs to the Dromiidae family, commonly known as sponge crabs. Australia is home to many species of sponge crab, and this is one of the few places where the new species is found.
Crustaceans in this family use sea sponges and sea squirts, animals that include sea squirts, for protection. They cut the creatures with their claws and wear them as hats, as seen in this image by Colin McLay.
The curator of crustaceans and worms at the Western Australian Museum, Andrew Hosie , said that sponge crabs had specially adapted hind legs to support their protective hats. And it is that hair has many purposes within the animal kingdom. In this case, it’s like a wig-shield made of living sea sponge.
According to experts, the crabs cut the living sponge to shape, let it grow to form the shape of their body, and use it as a hat or protective blanket to keep them protected from predators such as octopuses and fish. It is another form of camouflage used by these shallow water crabs.
So, similar to how hermit crabs use shells to protect themselves, sponges help Dromiidae crabs camouflage themselves from predators like octopuses and even other crabs.
In addition, sponges produce chemical compounds that are very harmful to some animals; so it is unlikely that predators will try to bite it in the face of such a deterrent defense.
Although all members of this group of crabs use sponges as a defense wig, the case of this crab is unique. It is incredibly furry and soft, experts say.
Reference: WA Museum.
