Question 5
Which among the following is exclusively a marine animal?
(a) Porifera
(b) Echinodermata
(c) Mollusca
(d) Pisces
Ans) (b) Echinodermata
Echinoderms are exclusively free living and marine animals. Porifera consist of sponges which are aquatic. Most sponges are marine but few are fresh water forms. Molluscs are marine as well as terrestrial forms. Pisces are found in both marine and fresh water.