Question

The only freshwater organism in phylum Cnidaria is ________.

Answer 1

Cnidaria:

1. This phylum is also called Coelenterata.
2. Animals belonging to this phylum are aquatic and exclusively marine.
3. They are generally attached to rocks, i.e., they are sessile.
4. Hydra is the only freshwater organism under this phylum.

Final answer: The only freshwater organism in phylum Cnidaria is Hydra.