So it looked like a star...a brittlestar or a starfish? There are 6 armed brittlestars (genus Ophiactis)in that size range that reproduce by splitting, so that three arms are shorter than the others. How did the arms move? With a rowing type motion?
Perhaps you could describe it a bit more? It sounds kind of like it moves like a brittlestar (first arm leading, two on side 'rowing' a bit and others just kind of dragging behind), which sometimes make a move to a different whole in the rock. Was there a distinct central area to the animal? Was it flat? Were there spines? Coloration? Hopefully we can figure out what it was!
ophiuroid: Thanks. Looked at brittlestars site. This didn't have long skinny arms or legs. Much more like true star fish except had 6 arms. Sounds like you mentioned. Front arm pulling, other two kind of rowing and little back 3 arms dragging. There was a distinct central area and all appeared to be flat. Didn't see any spines..but it was gone before I got magifing glass. It really appeared to be pure white. Been looking and haven't seen it again. Is this another hitchhicker? Is it good, bad or indifferent? Gosh, wish I got picture! Thanks again.
some'n'smellsfishy..Thanks. Glad to know they shouldn't be harmfull.
This mini star just showed himself again last night on front of tank. So, I could see bottom and it sure looks like some kind of star fish. This morning it was hitching a ride on a snail. I thought stars had 5 arms..this one has six.