see through blob thing...what is it

[nicks nano reef]

over the last 2 days i have seen a see through blob on the front glass of my culturing tank at first i just asummed it was an air bubble caught by the algae but then the next day i noticed it had moved so today idecided to poke it off the glass it started swimming in a pulsationg motion and swam out of sight has any one ever seen any thing like this?

 

[Mike J.]

Boy that's hard to guess at. How about a polyclad flatworm?

 

[redfishbluefish]

You don't mention the sze, but my first thought from the "pulsating" comment, is a nudibranch.

 

[Reefing Madness]

You don't mention the sze, but my first thought from the "pulsating" comment, is a nudibranch.

This was my first thought also.

 

[Mike J.]

"See through blob thing", like this?

http://www.hawaiisfishes.com/inverts/polyclad_flatworms/images/Acotylean1_JPG.jpg

 

[Reefing Madness]

That thing swims? What the heck is it?

 

[Mike J.]

It's a Polyclad Flatworm. I had one and I think it eats a snail per night. They usually live under a rock or the sand and come out at night. They are very fast movers - gliding on the glass or sand. See one, don't take pictures, grab it now! I learned that the hard way. Let's see if I can find when I made that mistake. Here it is: