AMPHIBIOUSES, amphibians (grech, amphibia leading double life) — a class of the land vertebrate animals who kept a number of lines of water ancestors. Change of conditions of dwelling is characteristic of their ontogeny: caviar, similar fish, 3. postpone in water where it develops to a stage a metamorphosis (transformations), later to-rogo an organism loses looking alike fishes and gains lines of the mature animal adapted for dwelling on the land. It is known apprx. 3000 types 3., extended everywhere.
3. live in gardens, fields, kitchen gardens, the woods, where exterminate wreckers (insects, mollusks, etc.) and by that bring big economic benefit. Advantage 3. is defined also by the fact that the main forage of many of them are carriers of some diseases and intermediate owners of helminths (e.g., the most part of a diet of an ordinary triton larvae of mosquitoes make, an edge triton — a small pond snail). In turn 3. serve as a forage for some valuable fur-bearing animals, fishes and other animals. Frogs, tritons, axolotls, etc. are widely used in quality laboratory animals (see) at various medical - biol, researches. In a number of the countries of Europe, Asia and America frogs are eaten. Poison of skin glands 3. (in particular, toads from the sort Bufo) apply as the means healing wounds and stimulating cordial activity.
Negative value 3.: some types are natural keepers of individual dangerous infectious diseases (e.g., tularemias).
Bibliography: Life of animals, under the editorship of L. A. Zenkevich, t. 4, p. 2, M., 1969; T e-rentyev P. V. Gerpetologiya, M., 1961; Shmalgauzen I. I. Origin of land vertebrata, M., 1964.