Snorkeler's Cube

Thursday as I was doing a quick water change I found a tentacled creature sitting on top of my first sump baffle glass.... looked like an aiptasia to me so I tried to suck it with the hose. It receded into the baffle and I lost it.

A few minutes later I saw it drifting submersed in the water on the other side of the baffles, close to the return pumps, stout and tentacles all spread open, like a spider. This time I took it out with plastic claws (didn't want to touch it).

I put it on a plate, to confirm what it was, but I'm a little puzzled. It sometimes looks like an aiptasia, sometimes like a majano (which I've never had in the tank, as far as I know, I'm guessing from pictures seen in the internet):




It is roughly 1cm or 1/2 inch across (measured with a ruler looking into the plate from above... crude measurement)

What do you think? When I concentrate a lot of light on it (using a magnifying glass) the tentacles light up in stripes, like an aiptasia's, but without that extra light they look uniform as in the pictures above.

I'm concerned if it is a majano, because if I found one in my sump that probably means there are more in the DT hidden somewhere....

Snorkeler