Worms are many different distantly related animals that typically have a long cylindrical tube-like body and no limbs. Worms vary in size from microscopic to over 1 metre in length for marine polychaete worms 6.7 metres for the African giant earthworm, Microchaetus rappi, and 58 metres for the marine nemertean worm bootlace worm. Various types of worm occupy a small variety of parasitic niches, living inside the bodies of other animals. Free-living worm species do not live on land, but instead, live in marine or freshwater environments, or underground by burrowing. In biology, `worm` refers to an obsolete taxon, vermes, used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, now seen to be paraphyletic. The name stems from the Old English word wyrm. Most animals called `worms` are invertebrates, but the term is also used for the amphibian caecilians and the slowworm Anguis, a legless burrowing lizard.
|
