Question

Which of the following animals does not undergo metamorphosis?

• A. Starfish
• B. Earthworm
• C. Moth
• D. Tunicate

Answer 1

The correct option is B Earthworm

Direct development refers to the process of development in which an animal is born in a smaller version of its adult form.

There is no larval stage and hence no metamorphosis in case of direct development.

Development in earthworms is direct and does not involve metamorphosis.

While in indirect development, the embryo hatches from the egg in a larval form which is morphologically distinct from the adult. The larva undergoes metamorphosis in order to achieve its adult stage.

Metamorphosis is the striking change of form or structure in an individual after hatching or birth. In tunicates (urochordates), moths and starfish the development is indirect and the larval form undergoes metamorphosis to become adult.