micro jellyfish ?

[eums]

i cant get a picture of them due to the high flow of my tank and i might see one every 2-3 months. there about 0.25" wide and about the same tall, there brown and look exactly like a jelly ( pumping the disk thing to swim around and all, but they cant fight 2,000 + gph of random flow in a 55 )

they look like an opaque little brown jelly. some one told me it could be coral spawn ? but i am not to sure about that ?
none of my fish eat it ( tomato clown, six line , or yellow tang).the jellys don't seem to do anything to my tank except just pop up every now and then ( i guess there reporducing ) i have alot of sps so i think i would notice if there stinging coral.

i have alot of things in my tank lay eggs so i am not sure if its hatching from an egg or what ?

any ideas as to what these are, next time i see one i will try to get it with a turky baster and take a picture of it in a cup.

[rshimek]

Originally posted by eums

Hi,

any ideas as to what these are...?

Sure. They are jellyfish. Depending on the shape they are either being produced from some hydrozoan or from scyphozoan polyps in your system. Corals, sea anemones, soft corals, and mushroom polyps do not have jellyfish as part of the life cycle, but both hydrozoans and scyphozoans do.

For images of both of these, follow this link and go down the page:

http://www.rshimek.com/odd_critters.htm#Dots%20with%20legs,%20Part%202.%20%20Cladonema%20jellyfish

Here is an image of the basic hydrozoan life cycle:
http://reefcentral.com/gallery/data/500/419903afig3.jpg

[eums]

sure looks like i have Hydroid Jellyfish. what can i do to rid them from my system.

[rshimek]

Hi,

Generally, the best cure is manual removal. Kalk paste often seems to work best. Do a search of this forum using "hydroid" and "removal" as your search key words and you will see what kind of cures people have considered.

[asn]

I just noticed some in my tank too. Are they harmful?

[rshimek]

Hi,

Jellyfish? No, they are generally not harmful.

The hydroid polyps may, on occasion, become pests. Most of the time, however, they are not a problem.