Earthworm | earthworm
earthworm,anyoneofmorethan1,800species[1]ofterrestrial[2]wormsoftheclassOligochaeta[3](phylumAnnelida)—inparticular,membersofthegenusLumbricus[4].Seventeennativespeciesand13introducedspecies(fromEurope)occurintheeasternUnitedStates[5],L.terrestris[6]beingthemostcommon.Earthwormsoccurinvirtuallyallsoilsoftheworldinwhichthemoistureandorganiccontentaresufficienttosustainthem.OneofthemostdetailedstudiesofearthwormactivitieswasconductedbyEnglishnaturalistCharlesDarwin[7].MembersofoneAustralianspe...
earthworm, any one of more than 1,800 species[1] of terrestrial[2] worms of the class Oligochaeta[3] (phylum Annelida)—in particular, members of the genus Lumbricus[4]. Seventeen native species and 13 introduced species (from Europe) occur in the eastern United States[5], L. terrestris[6] being the most common. Earthworms occur in virtually all soils of the world in which the moisture and organic content are sufficient to sustain them. One of the most detailed studies of earthworm activities was conducted by English naturalist Charles Darwin[7].
Members of one Australian species can grow as long as 3.3 metres (about 11 feet). L. terrestris grows to about 25 centimetres (10 inches). This species is reddish brown, but some earthworms (e.g., Allolobophora chlorotica, native to Great Britain) are green. The reddish tinge of L. terrestris results from the presence of the pigment hemoglobin in its blood[8].
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