Minute Brown Pulsing Discs ?

[Patti]

Hi Everybody,
As I was feeding my fish today, I noticed at the surface of the water hundreds of pinhead size brown discs, they pulsed like jellyfish, and there are scads of them at the water surface. Could they be bristle worm larvae ? All I have in the tank are 4 peppermint shrimp, 2 percula clowns,a scooter blenny and 3 seahorses, ( I should have mentioned it is a lagoon type setup. Also some gorgonians and 2 red algae plants.

Thanks In Advance For Any Help,
Patti

 

[Manofathousandpolyps]

Chances are theyre jellyfish. I posted something like this a couple weeks ago. If its the same thing I have they will do no harm. If anything they will make good fish and coral food.

 

[sMARTY]

I had for a while, exactly what you are describing, except that mine started as Polyps. On several of my live rocks, I had some tiny clumps of little brownish polys on little Stick looking "stems". Every so often some of the Polyps would start pulsing on their stems. After several hours of pulsing, they would break away, and drift through the current with the same pulsing action that jellyfish use. This makes sense, as Polyps, and jellyfish are closly related, and some of these animals have both medusa and free swimming stages in their life cycle.

 

[Manofathousandpolyps]

Mine started the same way. They are hydroids.

 

[danmhippo]

I used to have hundred of these coming from nowhere. The timing coincide with the setup of Ecosystem sump. Mostlikely they are from the introduction of caulerpa rocks.

in my case, I had hundreds of brown upside down jellyfish and they were reproducing like crazy. I even sell bags back to LFS.

 

[Patti]

WOW !

Will this hobby ever stop surprising me ?

I'm gonna keep an eye out for these things and keep track of when they appear. They seem to have all disappeared now, I imagine my clowns and seahorses may have gobbled up a few.
Sure was neat though !

Thanks Everyone !
Patti

 

[whusband]

I saw a really cool show on ETV the other night about moon jelly fish. Part of their life cycle is the polyp stage. It was part of a series - The Fabric of Life. you can see a schedule for that series here

 

[Manofathousandpolyps]

Hey I saw that too. Very cool show.