Jellyfish Larva?

[Sparky477]

It swims like a jelly and it looks like a jelly but is it in fact a jelly? The photos are blown up quite a bit since it's about the size of the letter "O" in my tank.




I have more photos at Weird Things In My Tank

 

[MT79]

Sounds more like a hydroid in it's medusa stage, although it could be a jelly I guess. They can appear similar, but hydroids seem to be more common in reef aquariums.

 

[Devilishturtles]

Hitchhiker jellys are not common, so like Mike said it could either be a hydroid or jelly. I think it may be a jelly in fact, in it's polyp stage. Did you recently add anything new to your tank? Macroalgae? Livesand? Liverock? Nice pictures by the way.

If the polyp makes it so "adulthood" it can grow and start stinging your corals (and you!) and generally be a nuisance. Most don't make it past the stage it's in right now though, not enough food.

 

[Sparky477]

Did you recently add anything new to your tank? Macroalgae? Livesand? Liverock? Nice pictures by the way.

That's the fist thing I said to myself: "What the heck did I add recently", but the only thing I've added recently is salt water and fresh water makeup I got from my local tropical fish store. I noticed them when I had the pumps off during feeding, hopefully they were an exception and not a rule. Thanks for the ID.