Larva Larva A larva (plural: "larvae" ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form ("e.g." caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to environments separate from adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water
Crustacean larva and hatch with a full complement of adult appendages with the exceptions of the uropods and the first pair of pleopods. The larvae of the Achelata (slipper lobsters and spiny lobsters) are unlike any other crustacean larvae. The larvae are known as "phyllosoma", after the genus "Phyllosoma" erected by William Elford Leach in 1817. They are flattened and transparent, with long legs and eyes on long eyestalks. After passing through 8–10 phyllosoma stages, the larva undergoes "the most profound transformation at a single moult in the Decapoda", when it develops into the so-called "puerulus" stage, which is an immature form