A worm is an elongated soft-bodied invertebrate animal. The most famous is the earthworm, a member of phylum Annelida, but there are hundreds of thousands of different species that live in a wide variety of habitats other than soil. Invertebrate is a term coined by Chevalier de Lamarck to describe any animal without a backbone or vertebra, like insects, squids and worms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Bilateria Acoelomorpha Orthonectida Rhombozoa ? Myxozoa Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Earthworm is the common reference for the larger members of the Oligochaeta (which is either a class or subclass depending on the author) in the phylum Annelida. ... The taxonomic system recognizes the generally accepted grouping of animals with certain evolutionary traits into taxa below the kingdom level, called phyla (the plural of phylum). ... Classes and subclasses Class Polychaeta (paraphyletic?) Class Clitellata    Oligochaeta - Earthworms and others    Acanthobdellida    Branchiobdellida    Hirudinea - Leeches Class Myzostomida Class Archiannelida (polyphyletic) Class Echiura *Some authors consider the subclasses under Clitellata to be classes The annelids, collectively called Annelida, are a large phylum of animals, comprising the segmented worms, with about... In biology, a species is a kind of organism. ... For the heavy metal band see Soil (band) Soil is the layer of minerals and organic matter, in thickness from centimetres to a metre or more, on the land surface. ...

Originally, the word referred to any creeping or a crawling animal of any kind or size, such as a serpent, caterpillar, snail, or the like. Later this definition was narrowed to the modern definition which still includes several different animal groups. Major phyla include:

• Acanthocephala (spiny-headed worms)
• Annelida (segmented worms)
• Chaetognatha (arrow worms)
• Gnathostomulida (jaw worms)
• Nematoda (roundworms)
• Nematomorpha (horsehair worms)
• Nemertea (ribbonworms)
• Onychophora (velvet worms)
• Platyhelminthes (flatworms)
• Sipuncula (peanut worms)

Worms may also be called helminths, especially in medical or zoological terminology. Some other invertebrate groups may be called worms, especially colloquially. Many insect larvae are called worms, such as the railroad worm, woodworm, glowworm, or bloodworms. Classes Archiacanthocephala Palaeacanthocephala Eoacanthocephala The Acanthocephala (gr. ... Classes and subclasses Class Polychaeta (paraphyletic?) Class Clitellata    Oligochaeta - Earthworms and others    Acanthobdellida    Branchiobdellida    Hirudinea - Leeches Class Myzostomida Class Archiannelida (polyphyletic) Class Echiura *Some authors consider the subclasses under Clitellata to be classes The annelids, collectively called Annelida, are a large phylum of animals, comprising the segmented worms, with about... Classes Archisagittoidea Sagittoidea Chaetognatha is a phylum of predatory marine worms that are a major component of plankton worldwide. ... Gnathostomulids, or jaw worms, are a small phylum of microscopic marine animals. ... Classes Adenophora    Subclass Enoplia    Subclass Chromadoria Secernentea    Subclass Rhabditia    Subclass Spiruria    Subclass Diplogasteria The roundworms (Phylum Nematoda) are one of the most common phyla of animals, with over 20,000 different described species. ... Nematomorpha (commonly known as horsehair worms) are a phylum of parasitic animals morphologically and ecologically similar to nematodes. ... Orders Anopla Enopla Ribbon worms (Nemertina or Nemertea) are a class of symbiotic organisms, consisting of about 900 species. ... Genera Peripatus . ... Classes Monogenea Trematoda Cestoda Turbellaria The flatworms (Platyhelminthes, Greek platy: flat; helminth: worm) are a phylum of relatively simple soft-bodied invertebrate animals. ... The Sipuncula, sipunculid worms or peanut worms, are a phylum of marine worms with a tentacle surrounded mouth on a completely invertible head end. ... See drugs, medication, and pharmacology for substances that are used to treat patients. ... Zoology (Greek zoon = animal and logos = word) is the biological discipline which involves the study of animals. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ... Species several The railroad worm is a larva or larviform adult of beetles of the genus Phrixothrix in family Phengodidae, characterized by their unique possession of two different colors of bioluminescence. ... A woodworm is not a specific species. ... Glowworm is a term referring to a bioluminescent invertebrate of any of several families. ... Blood worm or bloodworm is an ambiguous term and can refer to: A midge larva The polychaete Glycera This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

When an animal, such as a dog, is said to have worms, it means that the dog is infested with parasitic worms such as tapeworm (or the fungal ringworm). Trinomial name Canis lupus familiaris The dog is a canine carnivorous mammal that has been domesticated for somewhere between 14,000 and 150,000 years. ... Tapeworm can mean: Tapeworm, parasitic flatworms that live as adults in the digestive tracts of vertebrates. ... Ringworms can also refer to fans of the Japanese Ring series of horror novels and films, as well as the US remake. ...