Question

Ephyra is the stage in the life cycle of

A. Rana tigrina
B. Obelia
C. Aurelia
D. Adamsia

Answer 1

The term ephyra is obtained from Greek word Euphra, a sea nymph. Thus, ephyra is a stage in the life cycle of a marine organism.

Complete answer:
Rana tigrina is the scientific name of the Asian bullfrog. Life cycle of Rana tigrina comprises eggs, tadpole larvae which metamorphose into adults. These animals are fresh-water amphibians distributed across the entire Indian sub-continent.

Obelia commonly known as sea fur are a group of marine animals belonging to the phylum Cnidaria. Obelia has asexual polyp stage and sexual medusa stage in its life cycle. These animals begin life as tiny freely swimming larvae called planula; the planulae settle down and grow up to polyps. Polyps reproduce asexually to form medusa which are free swimming and reproduce sexually to produce the planula.

Aurelia are a genus of jellyfish commonly called moon jellies. These marine animals also belong to the phylum Cnidaria. The lifecycle of these animals consists of tiny planula larvae which are attached to form a polyp and from the polyp emerges the ephyra. The larvae of medusa stage in Aurelia are called ephyrae (singular ephyra) and they mature into sexually reproducing adult medusa.

Adamsia are commonly known as sea anemones. These are marine animals. Their life cycle consists of free-swimming planula larva which then settles down to form a juvenile sea anemone that eventually grows into an adult. Adamsia are often symbiotic with hermit crabs, i.e., anemones are found to grow in gastropod shells also harbouring hermit crabs. These animals reproduce sexually.

Hence the correct answer is OPTION(C)

Note: Obelia, Aurelia, and Adamsia all belong to the phylum Cnidaria. All these groups of animals have a free-swimming planula stage, but planula is followed by different larval stages.