Question

Respiratory organs of Asterias are

• A. Ctenidia
• B. Lungs
• C. Gills
• D. Dermal branchiae and tube feet

Answer 1

The correct option is D Dermal branchiae and tube feet

Asterias which is commonly known as starfish is an exclusively marine bottom dwelling animal. These marine vertebrates have a central disc shaped body with five arms have an oral and aboral surface. The oral side has the mouth, ambulacral grooves, tube feet or podia, ambulacral spines, and sense organs. The aboral surface has papulae or gills, spines, anus, madreporite and pedicellariae. These organisms do not have true heart. There is no respiratory pigment in the blood. The exchange of gases occurs by different organs in different organisms. Gaseous exchange takes place through the dermal branchae or papulae in starfish. The genital bursae is involved in respiration in the brittle stars. There are peristominal gills which acts 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. The dermal branchiae and the tube feet perform the functions of respiratory organs in case of Asterias.

Thus, the correct answer is option D.