At first glance these you would not think these are Sea Cucumbers but, of course, they are…
Their bodies are buried in the sand and they stick their heads and feeding arms out to catch the particles passing in the current.
They are fascinating to watch as their out side arms contract into their mouths. Once in their mouths, they have a double set of cleaning arms, one set cleans and then remaons in the mouth, while the other set that has been in the mouth re-sets themselves in preparation for the next outer arm. Very clever design..