Worm
The term
worm /ˈwɜrm/ is used in everyday language to describe many different distantly related animals that typically have a long cylindrical tube-like body and no legs. 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, and 55 metres for the marine nemertean worm,
Lineus longissimus. Various types of worm occupy a small variety of parasitic niches, living inside the bodies of other animals. Free-living worm species may live on land, in marine or freshwater environments, or burrow. In biology, "worm" refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and 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 slow worm
Anguis, a legless burrowing lizard.