Fleshy starfish like this one move by thousands of tiny tube feet on their underside. It's almost as if each arm is a millipede, but the millipede legs end in suction cups. The overall effect of their locomotion is a gliding movement. Here's a good YouTube look at the tube feet underneath: http://youtube.com/watch?v=4IRF-pKVtuU
Brittle stars, skinnier starfish relatives, do move more by walking with their legs.
Hi. I made this time lapse. It was filmed outside on rocks that created something like tidal pools. Mostly just rocks covered in seaweed, barnacles, snails and other critters. Its difficult to see that the orange sea star comes about half out of water in its shot, and then goes back under again. I used a polarizer to cut glare off the water. I'm also surprised that the lighting came out so well, but it was a clear blue sky that day, so the light was steady, giving the appearance of indoor lighting. Not done in an aquarium though!
http://youtube.com/watch?v=4IRF-pKVtuU
Brittle stars, skinnier starfish relatives, do move more by walking with their legs.
Always cool to think of animals who move using hydrolics in their body, thats why they look like they are convulsing.
Oh well.
But to me it looks like these starfish arent underwater at all, at least near the end.