mini jellyfish in my tank!!! friend or foe?!

[nano6]

Okay so I had to turn off my powerhead today and to my suprise, I saw all sorts of "things" swimming in the still water. I saw some mysis shrimp paddling along as well as some worms drifting in the water. But what really shocked me was that I saw what I believe to be a mini jellyfish. It had a yellow center and seemed perfectly round. At the bottom near the tips, I saw I think 7 white dots. I'm pretty sure it was a jellyfish because of the way it moved, the way it contracted and "squirted" and jetted around. These things were tiny, I would say about the size of an " * " asterick on your keyboard.

What does this mean? Are these jellyfish friends or foes? I've never seen jellyfish in a reeftank, and I have vaguely heard about hydroids which are BAD for the tank, in which the jellyfish is the larval stage of hydroid life.

What do you guys think?

[reefboy77]

Can you get a picture?

[nano6]

it's WAY too tiny. It's like the size of an asterik (*) or an O. Somewhere in between. I don't think any digital camera can do a macro that small... except maybe an D-SLR. =/

[elisabeth]

most likely they were hydroids

[nano6]

good or bad? or indifferent?

[Puffer Daddy]

Funny you should post this...a while ago, I too had a "small" jellyfish in my tank..was a perfect mini...however, I believe he went over the falls as I have not seen him or another since. But it most certianly was a type of jelly fish...Mine was a little smaller than a pencil eraser.

[Reilly13]

I've had quite a few of those in my tank too, or maybe the same one round and around!
One of the clownfish tried to eat it QUICKLY spit it back out and darted away so it must have packed some punch for such a little thing.
Whether it's a Jellyfish or not I don't know, it looked like one, but it didn't seem hurt anything!

[elisabeth]

hydroids are harmless.

[nano6]

they're multiplying! WHen I turn off the powerhead I can see many more of them bobbing around.


Also a few are geting larger, and seem to be growing tentacles....

are they getting dangerous?

[Steve175]

Check out this link: http://archive.reefcentral.com/forums/showthread.php?s=&threadid=224200

Within it, has a link to pictures and description of hydroids. I've got many of them (when I bother to notice them) and, as they are harmless, I kinda like them.

2 cents. Steve.

[nano6]

This is a picture of what I have!

More and more daily I think. Some are getting larger... They usually stick to the glass (at least thats where I can see them)

when I turn off the powerheads... they start squirtin around.

[elisabeth]

when they look like they are sitting on the glass, under
magnification, they are actually moving.. pretty neat.

[Aquabucket]

I get the same hydroid jellys every once in a while. They usually only live for a couple of weeks and then they disapear.

[reefmarker]

I have what sounds like the same thing in my reefugium. My flame angel eats them immediately when they make it into the main tank. I never considered they may be jellyfish.

[elisabeth]

they're hydroids.

[TippyToeX]

A good link (http://www.rshimek.com/odd_critters.htm#Dots%20With%20Legs%20-%20Tiny%20Hydroid%20Jellyfish%20That%20Walk%20Around%20Tanks) About half way down the page.

Staurocladia oahuensis - Tiny Hydroid Jellyfish

[rosinbaum]

Wow thanks for that link. I just finished his sand bed info and Im about to try it direct with Gulf beach sand in my 55 Gal tank.