Originally Posted by
alix2.0
http:///forum/post/2618814
are zoa spiders... crabs?
Not really. They're arthropods, like crabs, but since they lack antennae and jaws, they're identified as chelicerates (with horseshoe crabs being one of the few crabs to join this exception). Since there are so many species of sea spiders, they exist in their own grouping as pycnogonida (I can't recall the exact interpretation, but I know it represents a group of animals that are noticably brought together as a bunch of legs and no central body), but they have definitely been tagged as chelicerates in the broader spectrum.
There is an article somewhere online I read a few weeks ago that tells you everything you need to know about them. As soon as I find it, I'll post up the link.