HEARTS (Vermes) — the general name of several types of the multicellular backboneless animals who are intermediate between coelenterates and arthropod.
H live in the seas, fresh reservoirs, various biotopes of sushi; many types of Ch. parasitizing at the person have medical value.
In total is apprx. 50 thousand types of Ch. combined in five types: type of flat worms (Plathelminthes) combining classes of ciliary hearts (Turbellaria), flukes (Trematoda), tape-worms (Ces-toda), tsestodoobrazny (Cestodaria); the type of roundworms (Nemathelmin-thes) combining classes of bryukhoresnichny (Gastrotricha), actually roundworms or a nematode (Nematoda), kinorinkh (Kinorhyn-cha), volosatikovy (Nematomor-pha), rotifers (Rotatoria); the type of skrebny (Acanthocephales) including a class of skrebny (Acantho-cephala); type nemertin (Nemertini), the including class nemertin (Ne-mertina); the type of annlides (Ap-nelides) combining classes of mno-goshchetinkovy (Polychaeta) small shchetinkovykh (Olygochaeta), bloodsuckers (Hirudinea).
Trematodes, cestodes (see. Flat worms), nematodes (see Roundworms) and skrebn (see) are parasites of the person and animals. Getting into a human body, they cause diseases, sometimes heavy, leading to death. Special danger to the person is constituted by infection alveokokky (see Aljveokokkoz), a tape-worm wide (see Diphyllobotriases), pork and bull tapeworms (see Teniido-za), a dwarfish tapeworm (see the Hymenolepiasis), an echinococcus (see the Echinococcus), shistosomam (see Shissho-somatpoza), a cat's fluke (see Opistporkhoz), a trichinella (see the Trichinosis), a krivogolovka (see An-kilostomidozy), a parasitic worm (see D cancer a nka climbed), ascarids (see the Ascaridosis), filarias (see Filariases). The fluke is hepatic, moz-govik sheep, monneziya, threadworms, skrebn are capable to cause the epizooty sometimes leading to a mass murrain. The huge loss to sheep breeding is caused by the nematode of Dictyocau-lus filaria parasitizing in respiratory tracts of sheep. Many nematodes (potato, beet, wheat, gallic, stem, etc.) — the dangerous phytoparasites causing significant damage to agriculture. From annulate Ch. to the person and domestic animals is dangerous the horse bloodsucker sticking to mucous membranes of a mouth, a throat, a throat (at drink of water from reservoirs), urinary tract and generative organs (during the bathing in reservoirs).
Many free living Ch. are useful. Mnogoshchetinkovy annulate Ch. — polikhetam — eat different types of fishes. One of on-likhet — the Pacific palolo (Eunice vividis) — is eaten by the person. Food for juveniles of fishes are also the smallest of metazoans — the rotifers living hl. obr. in fresh-water reservoirs. Rotifers play an important role and in biol. self-cleaning of reservoirs. The big benefit to agriculture is brought by earthworms, improving structure of the soil and increasing its fertility. The medical bloodsucker (Hirudo medicinalis) is used in medicine (see the Bloodsucker).
Bibliography: Dogel V. A. Zoology
of invertebrates, page 290, etc., M., 1981; Life of animals, under the editorship of JI. A. Zenkevich, t. 1, page 337, M., 1968; Schultz R. S. and Gvozdev E. V. Bases of the general helminthology, t. 1 — 3, M., 1970 — 1976. Yu. K. Bogoyavlensky.