cryptobiosis(redirected from Osmobiosis)
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A state of life in which the metabolic rate of an organism is reduced to an imperceptible level. The several kinds of cryptobiosis (“hidden life”) include anhydrobiosis (life without water), cryobiosis (life at low temperatures), and anoxybiosis (life without oxygen). The most is known about anhydrobiosis.
States of anhydrobiosis occur in early developmental stages of various organisms, including seeds of plants, spores of bacteria and fungi, cysts of certain crustaceans, and larvae of certain insects; they occur in both developmental and adult stages of certain soil-dwelling micrometazoans (rotifers, tardigrades, and nematodes), mosses, lichens, and certain ferns.
A central question in the study of anhydrobiosis has been whether metabolism actually ceases. Available evidence strongly suggests that dry anhydrobiotes are ametabolic. In that case, a philosophical question immediately arises concerning the nature of life. This philosophical quandary can be avoided by applying the definition of life adopted by most students of anhydrobiosis: an organism is alive, provided its structural integrity is maintained. When that integrity is violated, it is dead. See Metabolism