Never seen this before...

[DSC reef]

Looks like an aptasia. I've seen small ones jet across the tank before.

 

[Mark Novack]

Dipped some new corals today and saw this critter swimming around. Can’t assume it’s a good thing!?!

Very interesting. I was just watching a very similar looking creature in my tank thinking about your photo but before I could get my camera it was eaten by my Loricula. Between the angels, triggers and Labridae, not many hitchhikers make it across the open water column. I do have snails. Very smart snails.

 

[Millimylilly]

Wow that is amazing I had no idea anemones could swim like that