Skip to main content

Definition: Metamorphosis from Hawley's Condensed Chemical Dictionary

A process of developmental change whereby a larva reaches adulthood only after a drastic change in morphology; occurs in most amphibians and insects; for some insects, this change may include another stage (pupa) before the adult stage.


Summary Article: metamorphosis from Philip's Encyclopedia
Whtadpol
Image from: tadpole in Word Histories and Mysteries

Change of form during the development of various organisms, such as the changing of a caterpillar into a moth, or a tadpole into a frog. Sometimes the change is gradual, as with a grasshopper, and is known as incomplete metamorphosis. Complete metamorphosis usually involves the more distinct stages of larva (such as a caterpillar), pupa (with a protective outer casing), and imago (winged adult).

metamorphosis

When common frogs mate, fertilization and egg laying occur in water (1). Within an hour, the jelly around the egg swells to produce frogspawn (2). The eggs develop (3) and produce embryos (4) that hatch as long-tailed tadpoles with external feathery gills six days after fertilization (5). Mouths and eyes develop later and the tails become powerful means of propulsion. Hind legs are well formed by week eight (6); meanwhile, the tadpole has changed from a herbivore to a carnivore. Via an intermediary gill and lung stage, the tadpole changes from gill- to lung-breathing, its internal lungs growing as its external gills are absorbed; the process is complete when the gills fully disappear at month three, by which time the forelegs are well developed (7). Metamorphosis is complete when the young frog (8) loses its tail.

Copyright © 2007 Philip's

Related Credo Articles

Metamorphosis
Bloomsbury Guide to Human Thought

Metamorphosis (Greek, ‘process of change of shape’) is the term, in the life sciences , for the dramatic reorganization of...

metamorphosis
The Encyclopedia of Ecology and Environmental Management, Blackwell Science

Transitional stage in organisms with a complex life cycle , involving the remodelling of a larval form into an adult morphology. Some groups,...

metamorphosis
The Macmillan Encyclopedia

The process in animals by which a larva changes into an adult. This radical change of internal and external body structures may be gradual...

See more from Credo