Aiptasia?

[EthanDouglas]

At my high school, we are currently running a 55 gallon FOWLR in my marine science class. The current stocking is 2 wild caught lion fish from the Gulf of Mexico, a large snail (that I forgot the name of. spiky looking shell and orange flesh?) and 4 sea urchins. Everything looks pretty good, the water is just a little cloudy.

I was looking around in the tank today and saw these

Aiptasia? Some other hitchhiker? I know that these were not introduced on purpose, but one could have come in on a shell and they just spread. These are the only 2 I've seen.

 

[EthanDouglas]

The second picture is the snail shell. I first noticed it a few weeks ago but paid no attention to it. It looked like it was completely dead. It is definitely the larger one, which leads me to believe it was the first and spread.

 

[cloak]

+1 Aiptasia.