Question

Which echinoderm does not possess arms?

• A. Asterias
• B. Echinocardium
• C. Ophiura
• D. Astropecten

Answer 1

The correct option is B Echinocardium

A) $\text{Asterias}$ (star fish) has five arms.

B) $\text{Echinocardium}$ is a heart shaped sea urchin which has no arms.

C) $\text{Ophiura}$ (brittle star) has five arms.

D) $\text{Astropecten}$ (large star fish) has five arms.

So, the correct answer is '$\text{Echinocardium}$'.