Very small Jellyfish in refugiums?

[Tony Quinn]

On doing a night dive this week in my refugium, I noticed what appeared to be very small jellyfish. The animals in question were brown in colour and had a a diameter of approximately 3mm. Their bulbous discs pulsated like their larger cousins and the central body appeared clear. I am not sure if they are spawned from what appears to be 5mm stalks attached to the inside of the refuge walls, growing on a stem and finally becoming free swimming. Any experiences of similar organisms encountered by other reef keepers. There are only microfauna in this refuge and some larger species of work in the DSB (4-5")

 

[Marrowbone]

Sounds like the "hydroids" referred to in the hitchhiker FAQ section here. There is a link on that page to more detailed info on these guys:

http://www.animalnetwork.com/fish2/aqfm ... efault.asp

I have quite a few of these things in my tank and i recently witnessed one in the act of releasing a free swimming "jellyfish" just like what you are referring to.

 

[Tony Quinn]

Have researched these pictures but have not seen the species I've found in the fuge. It has no visible tenticles, merely a disc that pulsates, most hydroids I've seen have tenticles. Were yours like I describe or with tenticles?

 

[danmhippo]

I think you may have "upside down jellyfish". Search in Googles will come up with hundreds of links. Their eggs are often attached with Florida LR or macro algae. I used to have thousands of these in my tank. It's a surprise to me that they appeared in my tank, flourished, and disappeared. I do not know why they disappeared in my tanks.

 

[Marrowbone]

Mine have tentacles, they look just like the photo in the hitch-hikers guide here (if you can see anything there :lol: ) They seem to be the generic species of hydroid in tanks, but there are tons of varieties apparently. Cool that you have something different (from me anyway :lol: )

 

[Tony Quinn]

Damnhippo! spot on, I didn't want to say they looked liked upside down jellyfish having studied some marine biology, the term crossed my mind as a little zany! They seem to pulsate upside down but the rock is definately Fijian, the macro, who knows!? They are multiplying and growing and being in the refuge no predators seem to be wiping them out. I must admit they are fascinating to study (I'm not an anorak by the way!!!). There are also another species of jellyfish in the fuge which are more like something from 'Close Encounters of a Third Kind'. They are clear but appear to have 4 illuminated dots at the base of the body, infact they don't appear round but cylindrical.

 

[wombat1]

Any chance of pictures??

 

[reefNewbie]

yea really! i want to see some pics

 

[Tony Quinn]

I don't think my camera (not being digital) will be able to pick up these miunte creatures, maybe the brown ones but the others, I can barely see them without patient study! I will try and then see if I can scan the photo onto my system.

 

[MaryHM]

Try this:

http://www.reefsource.com/Photo%20Galle ... lyfish.htm