Topic: sea spider

sea spider common name for members of the class Pycnogonida, long-legged, rather spiderlike organisms of the phylum Chelicerata, widely distributed in marine waters. Most are tiny, from 1 to 9 mm (0.04-0.36 in.), and live in littoral regions, crawling about over the surface of sessile animal colonies or seaweeds. Some live on or in clams. There are deep-sea forms, some becoming quite large; Colossendeis colossea has a leg span of nearly 2 ft (91 cm). Their unusual body form makes their relationships to other arthropods obscure. Nearly all of the body is composed of the anterior region (prosoma);... Read more