Sea spiders, which range in size from around a millimetre long to the size of a large dinner plate, have relatively tiny torsos and six pairs of long, lanky legs. For these creatures, legs are for ...

Sea spiders eat a diet of worms, jellyfish, sponges, soft corals, and other soft-bodied sea creatures. The most unique feature of the sea spider’s anatomy is its legs.

Spiders are not found in the sea. Its body structure is also different from that of crabs. I checked and it seems to be a member of the rare, marine arthropod, probably a member of the Pycnogonida.