Paromola cuvieri

Image: OCEANA

This is just like that bit in Star Trek where Captain Kirk completely overreacts to a man in a lizard-suit throwing a lump of foam at him.

This crab makes for a far more convincing alien, though.

Image: OCEANA

What we're seeing is Paromola cuvieri, a deep sea crab that resides in the eastern Atlantic, near Africa and Europe. They generally prefer depths below 150 metres (500 feet).

P. cuvieri is typical of members of the Homolidae family, the carrier crabs. They're crabs that carry stuff. Here we see one carrying a sponge over her head. It's only a sponge, so there's no need to overreact if she throws it at you.

Image: OCEANA
Alone :(

Male P. cuvieri have a body up to 20 cm (8 in) long and can reach 1.2 m (4 ft) across if you include their long pincers. Females are somewhat smaller and have much smaller pincers.

Regardless of how big their pincers are, their hindmost legs are tiny in comparison. Akin to the Sponge Crabs, they have small hind legs positioned in such a way that they can put their legs in the air like they just don't care...

Image: OCEANA
This appears wholly insufficient for any conceivable purpose

Or they can carry stuff. Paromola crabs have been seen carrying sponges, corals or flimsy bits of bryozoans above their head.

Presumably it helps defend or camouflage them from predators but it must be nice to have a bit of decorative company, too.