See text Pycnogonum is a genus of sea spiders in the family Pycnogonidae.

[2][3][4] Members of the genus Pycnogonum have squarish bodies with a tough integument and a few hairs.

The cephalon (the anterior end of the body which is fused with the first segment of the trunk) has a long smooth proboscis and a low tubercle on which the eyes are set.

There are no chelicerae or palps and these sea spiders use their proboscis to suck juices from their prey.

The four pairs of ambulatory legs are short but strong, with well-developed terminal claws.