The hormonally-driven transition from a larval stage to an adult in which a significant proportion of the organism’s structure changes such that the larval and adult stages are often not recognizable as the same individual. Thus, it is a process of qualitative and radical change in both structure and function from the embryo to the adult in two or more stages. There are two general types of metamorphosis. In the first, shown by amphibians and insects, there is metamorphosis with a change in habitat (e.g., from an aquatic to an air-breathing habitat). In the second, metamorphosis takes place without a significant change in habitat (e.g., in many crustacean species). With insects, a further two types of metamorphosis can be distinguished: holometabolous (or complete) metamorphosis (larva to pupa to adult in, for example, beetles) and heterometabolous (or incomplete) metamorphosis (nymph to imago in, for example, locusts).
See Analogy (as a trope), Development direct (monogenesis) and indirect (metagenesis and metamorphosis) development, Metaphor, Morphogenesis, Ontogenetic adaptation, Ontogenetic development, Qualitative and Quantitative regressions