Question

Stone canal is a part of .............. structure of echinoderms.

• A. Digestive
• B. Respiratory
• C. Water vascular
• D. Excretory

Answer 1

The correct option is C Water vascular

In case of echinoderms, there is a water vascular system. This type of system is involved in the locomotion, respiration and supply of nutrients. The system comprises of stone canal, ring canal, madreporite and radial canals. The stone canal is S-shaped structure. The ampulla opens in the stona canal. The stone canal extends downwards and then opens into a ring canal. The ring canal is present around the mouth. The walls of stone canal are supported by a series of calcareous ring. The lumen of stone canal is lined by very tall flagellated cells. It leads from the madreporite to the ring of the water-vascular system surrounding the mouth.

Thus, the correct answer is option C.