Question

Respiration in echinoderms is by:

• A. Ambulacral groove
• B. Branchiae
• C. Book lungs
• D. Tracheae

Answer 1

The correct option is B Branchiae

Echinoderms are organisms that have calcareous endoskeleton which can be observed as spines. These organisms do not have true hearts and there is no respiratory pigment in the blood. The exchange of gases occurs by different organs in different organisms. The gaseous exchange takes place through the dermal branchiae or papulae in starfish. The genital bursae are involved in respiration in the brittle stars. There are peristomial gills that act as respiratory organs in sea urchins and cloacal trees are used for respiration in sea cucumbers. Exchange of gases also takes place through the tube feet in certain species.

Thus, the correct answer is option B.