larva

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larva

 [lahr´vah] (pl. lar´vae) (L.)
1. an independent, immature stage in the life cycle of an animal, in which it is markedly unlike the parent and must undergo changes in form and size to reach the adult stage.
2. something that resembles such an immature animal.
larva cur´rens a rapidly progressive creeping eruption caused by autoinoculation of larvae of Strongyloides stercoralis that migrate to and mature at the anus in intestinal infections with the parasite.
cutaneous larva mi´grans (larva mi´grans) a convoluted threadlike skin eruption that appears to migrate, caused by the burrowing beneath the skin of roundworm larvae, particularly of the species Ancylostoma; similar lesions are caused by the larvae of botflies. Called also creeping eruption.
ocular larva migrans infection of the eye with larvae of the roundworm Toxocara canis or T. cati, which may lodge in the choroid or retina or migrate to the vitreous; on the death of the larvae, a granulomatous inflammation occurs, the lesion varying from a translucent elevation of the retina to massive retinal detachment and pseudoglioma.
visceral larva migrans a condition due to prolonged migration by the skin larvae of animal nematodes in human tissue other than skin; commonly caused by larvae of the roundworms Toxocara canis and T. cati.

lar·va

, pl.

lar·vae

(lar'vă, lar'vē),
1. The wormlike developmental stage or stages of an insect or helminth that are markedly different from the adult and undergo subsequent metamorphosis; a grub, maggot, or caterpillar.
2. The second stage in the life cycle of a tick; the stage that hatches from the egg and, following engorgement, molts into the nymph.
3. The young of fishes or amphibians that often differ in appearance from the adult.
[L. a mask]

larva

(lär′və)
n. pl. lar·vae (-vē) or lar·vas
1.
a. The newly hatched, wingless, often wormlike form of many insects, developing into a pupa in species that undergo complete metamorphosis.
b. The six-legged immature form of a tick or mite.
2. The newly hatched, earliest form of any of various animals that undergo metamorphosis, differing markedly in appearance from the adult.

lar′val adj.

lar·va

, pl. larvae (lahr'vă, -vē)
1. Developmental stage or stages of an insect or helminth.
2. The second stage in the life cycle of a tick; the stage in which it hatches from the egg and, following engorgement, molts into the nymph.
3. The young of fishes or amphibians that often differ in appearance from the adult.
[L. a mask]

larva

(pl. larvae) the preadult form of many animals that is usually morphologically different from the adult, and which in many cases takes up the larger part of the life history. Usually the larva is not sexually mature, but in cases of PAEDOGENESIS, of which the AXOLOTL is an example, breeding may take place at this stage. Often the larva is a dispersal phase, as in many marine invertebrates where larvae occur in the PLANKTON and usually the larva feeds in a different way from the adult and does not compete with it.

Larva

The immature, early form of an organism that at birth or hatching is not like its parent and has to undergo metamorphosis before assuming adult features.
References in periodicals archive ?
Maternal nutrition could also influence the duration of the planktonic period by effects on larval form. Reduced maternal investment per offspring could mimic the effects of low concentrations of food for larvae, or it could affect the developmental plasticity of larvae in response to high or low concentrations of larval food.
We used our mtDNA phylogeny for Patiriella and Asterina species to test a series of hypotheses about the evolution of larval forms and modes of larval development in marine invertebrates.
Modern reliance on ballast water as part of commercial shipping offers a rapid vector for dispersal of the larval forms of these large predatory gastropods that supercedes natural zoogeographic boundaries and results in deposition of larval forms that have evolved under one set of ecological and environmental constraints into new habitats lacking these traditional controls.
Many marine invertebrate groups with different adult forms have similar larvae (such as the trochophore larva of mollusks and annelids, or the pluteus larva of sea urchins and brittle stars), and these similar larval forms are usually considered to be examples of either convergent evolution by natural selection or functional constraints on the evolution of early stages in development (Jagersten 1972; Strathmann 1988; Raff and Kaufman 1991; Wray 1992, 1995).
Smith, ed., Systematics Ecology Program, Marine Biological Laboratory, 1964) the larval forms of only 96 species have been described.
Coenurosis (gid or sturdy) has been principally a fatal disease of ungulates, especially goats and sheep, caused by larval forms of Taenia multiceps.
Comparing species with different egg sizes that develop via similar larvae reveals the flexibility and the constraints underlying larval forms. Clypeaster rosaceus is an echinoid that develops via a facultatively plank-totrophic pluteus larva.
If we are to be successful in restoration of oyster populations, we must understand the limitations of the larval forms within this new (to them) suite of adverse environmental variables.
For these supposed intermediate larval forms, food is no longer required and they are free to evolve dramatic changes in larval development, including accelerated development of juvenile structures and suppression of larval structures formerly used for capture and digestion of food (Jagersten 1972).
Other marine animals spend months swimming free in a variety of larval forms that are difficult to support in mariculture.