Juvenile (organism)

A juvenile is an individual organism (especially an animal) that has not yet reached its adult form, sexual maturity or size.

Some organisms reach sexual maturity in a short metamorphosis, such as ecdysis in many insects and some other arthropods.

For others, the transition from juvenile to fully mature is a more prolonged process—puberty in humans and other species (like higher primates and whales), for example.

In such cases, juveniles during this transformation are sometimes called subadults.

In vertebrates and some invertebrates (e.g. spiders), larval forms (e.g. tadpoles) are usually considered a development stage of their own, and "juvenile" refers to a post-larval stage that is not fully grown and not sexually mature.