Larva at Encyclopediaku

Sunday, July 14, 2013

For other uses, see Larva (disambiguation).

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Larva of Papilio xuthus, butterfly

A larva (plural larvae /ˈlɑrviː/) 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). A larva often has unique structures and organs that do not occur in the adult form, and may have a considerably different diet.

Larvae are frequently adapted to environments separate from adults.[citation needed] For example, some larvae such as tadpoles live exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, 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.[citation needed] Some species such as barnacles are immobile as adults, and use their mobile larval form to distribute themselves.

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

Eurosta solidaginis Goldenrod Gall Fly larva

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

Selected types of larvae

Animal	Name of larva
Cnidarians	planula, actinula
Crustacea: Decapoda	zoea
Insecta: Lepidoptera (butterflies and moths)	caterpillar
Insecta: Beetles	grub
Insecta: Flies, Bees, Wasps	maggot
Insecta: Mosquitos	wriggler
Certain molluscs, annelids, nemerteans and sipunculids	trochophore
Certain molluscs	veliger
Mollusca: freshwater Bivalvia (mussels)	glochidium
Petromyzontiformes (lamprey)	ammocoete
Fish (generally)	larva
Fish: Anguilliformes (eels)	leptocephalus
Amphibians	tadpole, polliwog
Phoronids	actinotroch
Porifera (sponges)	coeloblastula larvae (= blastula larvae), parenchymula (= parenchymella), amphiblastula
Cycliophora	pandora, chordoid larva
Nemertea	pilidium, Iwata larva, Desor larva
Hemichordata	tornaria
Acanthocephala	acanthor
Ctenophora	cydippid larvae
Deuterostomes	dipleurula (hypothetical larva)
Arthropoda: Xiphosura	euproöps larva ("trilobite larva")
Platyhelminthes	Götte’s larva, Müller's larva
Locifera	Higgins larva
Dicyemida	infusoriform larva
Brachiopoda	lobate larva
Priapula	loricate larva
Crustaceans	nauplius, metanauplius, protozoea, antizoea, pseudozoea, zoea, postlarva, cypris, primary larva, mysis
Arthropoda: †Trilobita	protaspis, meraspis, holaspis
Arthropoda: Pycnogonida	protonymphon
Urochordata	tadpole
Echinodermata	bipinnaria, vitellaria, brachiollaria, pluteus, ophiopluteus, echinopluteus, auricularia
Nematomorpha	nematomorphan larva
Sipuncula	pelagosphera larva
Annelida	nectochaeta, polytroch
Ectoprocta	cyphonautes, vesiculariform larvae
Heterocyemida	Wagener's larva
Nematoda	Dauer larva