tiny white swimmers

[leenie]

Can anyone tell me what these things are? They are too tiny to take a picture of...
They're small white round things that look very delicate- they swim like jelly fish- contracting through the water. They're almost microscopic, and I've begun noticing more and more. Some of them hang out by the back of the tank and some I see swimming around and then landing on rocks. The fish don't eat them.
Are they some sort of pod or animal??

 

[bang guy]

Sounds like Jellyfish to me.

 

[leenie]

Are they dangerous? What should I do about them?
I thought they looked like jellyfish, but didn't know it could be possible for them to survive in captivity.

 

[bang guy]

Don't eat them.

 

[bang guy]

Sorry, couldn't resist
They probably won't live long. Just enjoy them.
This does mean that you have some of the juvenile stage of hydroids in your tank though. They can become a problem because they "bud" so quickly. If you find the colony it would be good to kill them IMO.

 

[leenie]

Thanks Bang Guy! I won't eat em! Darn- we are having sushi tonight too. Would've been a great appetizer!

Okay- I will leave them be for now- but I'll heed your advice.
One more question...
I had a firefish die about 1 week ago (for no apparent reason). Could the Jellyfish have killed him? Or am I crazy??

 

[bang guy]

Nope, wasn't the jellyfish.