Which among the following is exclusively marine?
(a) Porifera
(b) Echinodermata
(c) Mollusca
(d) Pisces
Answer- (b)
Solution- Echinodermata have a water vascular system. Example- Starfish. They are marine animals.
Porifera lives in both saltwater and fresh water e.g., Haliciona and Spongilla.
Mollusca can live on the rocky shore, freshwater, saltwater, etc. Pisces can be freshwater or saltwater.
Thus, the correct answer is b)- Echinodermata.