Larva

A larva (Latin; 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. Larva is Latin for "ghost".

The larva's appearance is generally very different from the adult form (e.g. caterpillars and butterflies), and a larva often has unique structures and larval organs that do not occur in the adult form. A larva's diet can be considerably different from that of the adult form.

Larvae are frequently adapted to environments separate from adults. For example, some larvae such as tadpoles live exclusively in aquatic environments, but as adults can live outside water as frogs. By living in distinct environments, larvae may be given shelter from predators and reduce competition for resources with the adult population.

Animals in the larval stage will consume food to fuel their transition into the adult form. Some species such as barnacles are immobile as adults, and use their mobile larvae form to distribute themselves.

The larvae of some species can become pubescent and not further develop into the adult form (for example, in some newts). This is a type of neoteny.

It is a misunderstanding that the larval form always reflects the group's evolutionary history. It could be the case, but often the larval stage has evolved secondarily, as in insects. In these cases the larval form might differ more from the group's common origin than the adult form.

Names of various kinds of larvae:

Animal Name of larva
Hydrozoa planula
Many crustaceans nauplius
Decapoda zoea
Mayflies, Grasshoppers, True Bugs, etc. nymph
Dragonflies, Damselflies naiad, nymph
Butterflies and moths caterpillar
Beetles, Bees, Wasps grub
Flies maggot
Mosquitos wriggler
Certain molluscs, annelids trochophore
Certain molluscs veliger
Freshwater mussels glochidium
Lamprey ammocoete
Fish (generally) larva
Eels leptocephalus
Amphibians tadpole, polliwog
Sea stars Bipinnaria

See also