Question

Select the taxon mentioned that represents both marine and freshwater species.

Answer 1

Phylum having marine as well as freshwater species
The phylum Cnidaria (Coelenterata) consist of radially symmetrical aquatic organisms which can be free-swimming or sessile. Most of the species under this phylum inhabit marine habitats. However, some species live in freshwater as well.
For example,

• Freshwater species: Hydra
• Marine water species: Adamsia, Aurelia, Gorgonia etc.

Final answer
a. Cnidaria