Metamorphosis

Metamorphosis, in zoology, changes undergone from larvae to a mature adult stage. The term, meaning “transformation,” is generally used only for insects and amphibians, although other animals also have distinct larval and adult stages. Metamorphosis of insects may be complete, occurring in abrupt steps, or incomplete, a gradual process. Butterflies and moths have complete metamorphosis, changing from caterpillar to adult via one intermediate stage, the pupa. Grasshoppers and cockroaches mature gradually in a series of molts (the young are called nymphs) until they develop into adults. Metamorphosis of amphibians is generally from a water-dwelling, gill-breathing larva, such as a tadpole, into a less aquatic air-breathing adult, such as a frog.

See also: Zoology.