Question

Which among the following is exclusively marine?

विकल्प

• Porifera

• Echinodermata

• Mollusca

• Pisces

Answer 1

Echinodermata

Explanation - 

All the known members of Phylum Echinodermata (the spiny-skinned animals) are exclusively marine. Members of Phylum Porifera are mostly marine, rarely freshwater (e.g. Spongilla). Members of Phylum Mollusca are mostly marine. Many, however, occur in freshwater (e.g. Unio) and some even in damp soil (e.g. some snails and slugs). Members of Class Pisces are both marines as well as fresh water.