Question

what kind of fertilization present in coelentrata... external or internal?

Answer 1

Coelenterata is an obsolete term encompassing the animal phyla Cnidaria(coral animals, true jellies, sea anemones, sea pens, and their allies) and Ctenophora (comb jellies). The name comes from the Greek"koilos" ("hollow") and "enteron" ("intestine"), referring to the hollow body cavity common to these two phyla.[1][2] They have very simple tissue organization, with only two layers of cells (external and internal), and radial symmetry. Some examples are corals, which are typically colonial, and hydra, jelly fish and sea anemones which are solitary. Coelenterata lack a specialized circulatory system relying instead on diffusion across the tissue layers.

Answer 2

Dear Behna ✌️☺️

The polyp stage can be regenerated when medusae reproduce sexually to form a ciliated larva called a planula.

There are also some species that are exclusively medusae and donot form polyps.

Another variable in the sexual reproduction of cnidarians is whether fertilization takes place internally or externally.