Saturday 23 November 2013

How does a starfish move?

The ambulacral system is a water vascular system used for movement in echinoderms. It consists of numerous tubes inside the body and many other tubes that make up the ambulacral feet . The tubes are connected to tiny muscles that control the flow of water inside them. Contracting these muscles water is forced into the tubes and into the feet causing them to extend. Relaxing these muscles empties the tubes allowing the feet to retract. Starfish and other echinoderms move slowly using this hydraulic system.

 Many questions arose when we talked about this in the class. Here is a great video in which you can see how a starfish moves by moving its tiny ambulacral feet.



Our starfish, top side
Our starfish, underside
Starfish and ophiura

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