What is "sea spider"

Sea spider \Sea" spi"der\ (Zo["o]l.)

1. Any maioid crab; a spider crab. See Maioid, and Spider crab, under Spider.

2. Any pycnogonid.

alt. 1 Any arthropod in the taxonomic class ''Pycnogonida''. 2 Any marine animal whose appearance suggests a spider. n. 1 Any arthropod in the taxonomic class ''Pycnogonida''. 2 Any marine animal whose appearance suggests a spider.

n. any of various small spider-like marine arthropods having small thin bodies and long slender legs [syn: pycnogonid]

Sea spiders, also called Pantopoda or pycnogonids, ('pycno-' closely packed, 'gonid' gonidia) are marine arthropods of class Pycnogonida. They are cosmopolitan, found especially in the Mediterranean and Caribbean Seas, as well as the Arctic and Antarctic Oceans. There are over 1300 known species, ranging in size from to over in some deep water species. Most are toward the smaller end of this range in relatively shallow depths, however, they can grow to be quite large in Antarctic waters.

Although "sea spiders" are not true spiders, or even arachnids, their traditional classification as chelicerates would place them closer to true spiders than to other well-known arthropod groups, such as insects or crustaceans. However even this is in dispute, as genetic evidence suggests they may even be an ancient sister group to all other living arthropods.