Question

Define larva

Answer 1

Hint:Throughout the life cycle, the body continuously changes and goes through different periods known as stages. It occurs in the case of both animals and human beings.

Complete answer:
 Larva the plural form larvae or larva is the stage in the development of many animals. It occurs after birth or hatching and before the formation of adult form is reached. These immature active forms are structurally poles apart from the adults and they can adapt to a different environment. In some of the species, the larva is free-living and the adult is an attached or immobile form. In the other species the larva is aquatic and the adult lives on land. In forms with non-mobile adults the movable larva increases the geographic division of the species. Such larvae have well developed locomotor structures. A larva sometimes functions like a food gatherer. In many other species the larval stage occurs at a time when food is abundant and when they have a well-developed alimentary system. It stores food so that the alteration to the adult stage can occur. Some types of larvae function in both dispersion and nutrition.

The amount of time in the life cycle used up in the larval stage varies between species. Some have long larval periods either hatching early metamorphosing into adults late or both. Some organisms have a short-lived larval part or no larvae at all.

Larvae come out in a variety of forms. Many invertebrates e.g. cnidarians have a simple ciliated larva called a planula. Flukes have more than a few larval stages and annelids, mollusks, and crustaceans have a variety of larval forms. The larval forms of the different insects are called caterpillars, grubs, maggots, and nymphs. Echinoderms e.g starfish also have larval forms. The larva of the frog is tadpole.

Note:Types of larvae include oligopod which have well-developed thoracic legs. Polypod or eruciform: Their body consists of an extended trunk with large sclerotised head capsule. Apodous: They are larvae devoid of appendages for locomotion.