Jellyfish ?!?!?

[Sparkss]

We found this swimming around our 92 gal AGA corner tank this evening after main lights out (but the actinics were still on). It swims like a jellyfish, and looks like one also. It was initially caught by a photosynthetic gorg polyp, but managed to wiggle (pulse) it's way free after about 30 - 45 long seconds (just enough time for me to grab the turkey baster :)). Does anyone have an ID on this little guy ? The lines underneath are from a steno pad, for size comparison. And the picutres were taken as fast as our camera could focus and snap. so you can see the little guy is really getting around the dish we have him in :)


http://www.tomandjue.com/images/IMG_1260.jpg

http://www.tomandjue.com/images/IMG_1261.jpg

http://www.tomandjue.com/images/IMG_1262.jpg

http://www.tomandjue.com/images/IMG_1263.jpg

[DaRealDvs1]

Don't know what it is......but cool.:eek2:
I like finding new stuff in the tank.

[Sparkss]

The tank is over 1 year old and no new rock or coral colonies have been introduced in almost 9 months. I find it cool to find new things, but at this point finding something that is potentially predatory and potentially poisonous to my reef is most definitely not cool. :(

To me a jellyfish (if that is what it really is) is just an aiptasia that can swim (Which is similar to a recurring nightmare I have had recently :))

[DaRealDvs1]

LOL......true.


Good thing you caught it though.
You'll have to keep an eye out for more.

[JohnHenry]

Could it be a medusa polyp?

[Sparkss]

JohnHenry,

I will do a search on that to see if I can find pictures and/or a description. This little bugger sure did swim around like one, IE: the cilia surrounding it would contract and "pulse" propelling it forward, identical to what I have seen of the way a medusa swims.

[JohnHenry]

Well...to be truthful, I'm not exactly sure how to identify a medusa. If I'm not mistaken, many corals have a medusa stage before they settle down and grow into a coral. So it could be a coral gamete?

I would doubt that it's harmful, but better wait to hear from someone who knows more than I. Is it still alive?

[greenbean36191]

It's possible that it's a jellyfish, but the pictures aren't good enough to tell. Corals don't have medusae in their lifecycles though so it's not from a coral. It would either be from a hydroid or it's a true jellyfish. In either case it isn't likely to last long in your tank, but I would remove it on the slim chance that it's a hydroid medusa and it does survive to reproduce.

Just as a point of order, medusae and polyps are two different body types, so there is no such thing as a medusa polyp. It's either a medusa or a polyp. Also, medusae aren't gametes. Gametes are the sex cells, usually sperm and eggs. Medusae produce the gametes.

[Sparkss]

It was long removed, and we had no intention of re-introducing it, on the off chance it would reproduce (As you stated) or even so if it, by itself, managed to damage some prized coral. If it is still alive this morning I will try to get a small video of it's movement. Thanks for the feedback.

[Telgian]

Does it look like this?
If so, then it is possibly a Cassiopea jellyfish.
(More pictures in my gallery)

There is some information here (http://www.rshimek.com/cnidaria.htm) on jellyfishes; scroll down to 'Scyphozoan Jellyfish, Part 1.'


http://reefcentral.com/gallery/data/500/74878Jellyfish-med.jpg

http://reefcentral.com/gallery/data/500/74878GROUP1-1DarkDetail.jpg

[Edit: dug up a better picture and cropped it to fit in my gallery]

[rnoreef]

Be careful it's not one of those miniature box jellyfish that I just saw on Discovery channel. WOW how amazing that something so small could be so lethal. I know it sounds silly to think that one made it into your tank, but you can never be too careful.

[GinaSofia]

Did it look like this?
http://reefcentral.com/gallery/data/500/32832ID.jpg

[Sparkss]

Telgian,

It looked/looks like the bottom right hand, smaller specimen, in the second picture.

I just don't know where the devil it came from ?!?! Any thoughts? I will be reading up on the thread that you provided.. many thanks. :)

[Sparkss]

Gina,

No, it was flatter and appeared to have more "fingers" in it's outer "disc". Thanks though.

BTW, what is that a picture of ? it is almost beautiful, but it looks lethal/predatory.

[GinaSofia]

I was told it was a hydroid.It also pulsed around the tank.

[Telgian]

Hello again,

It looked/looks like the bottom right hand, smaller specimen, in the second picture.

They are all of the same type of jellyfish. However, there are different ages represented in the pictures.
The small one in the second picture was at the two week stage as a medusa. The larger one was around six weeks if I recall correctly.

I just don't know where the devil it came from ?!?! Any thoughts?

Yup.

On one or more of the rocks in your tank you have the polyp stage of the jellyfish happily munching on particulate matter/food and growing fatter.
After they get to a certain size, they pick up algae from their surroundings and incorporate it into their tissue, just like the corals do. (Jellyfish are also anthozoans).
At this point they gain the same benifits as corals do from the algae.
Once the polyps are at least 1.5mm across the widest part they might start to change into the medusa form.
Look for them swimming about in your tank on the days before and after the full moon. That's when you are most likely to see them.
Guess what phase the moon was in last night???

There are pictures of the polyps on the website that I gave you the link to.

If your critter is not pale white it will likely survive if you feed it and keep it in light.
They are benithic, and like areas with gentle water flow.

GinaSofia
Go to the same website that I linked to and scroll down to 'Dots with legs, Part 2. Cladonema jellyfish'.

Nice picture, btw. I haven't had the chance to catch one that close up yet. Or the Cassiopea polyps yet. Sooner or later...
:)

[Telgian]

GinaSofia,

I do have a bad picture of what I strongly suspect is the polyp form of your jellyfish here (http://reefcentral.com/gallery/data/500/74878PossibleHydroid3.jpg) in my photo gallery.

Have you seen these in your tank as well?

Telgian.

[Sparkss]

Thanks for the info Telgian.

I hd figured that the two forms in the picture were in different stages of their life cycle, but thanks for confirming that :)

One thing though is that we have not added any new rock to our tank in over 9 months.. so I guess their polyp stage is 8+ months ?

As for keeping it alive.. hehehe.. I am not much one for hydroids :) but thanks for the tips if we ever change our minds :)

[Telgian]

Scyphozoan jellyfish, not hydrozoan jellyfish.

[Sparkss]

I only skimmed the web page you sent me, but I just assumed (which is almost always a mistke) that all jellyfish are predatory in nature and detrimental to a closed reef system. Are you saying that this is not true of our little "ball of joy" ?

Yes, it is still alive and swimming around that same little dish that I took the pictures of it in :)

[Telgian]

The odds for a medusae living for long in a reef tank are not good.
Too many filters/powerheads/pumps, not to mention that some critters find them tasty.

I would just view them as plankton unless you see that they harm something.
You could turkey baster them into an aiptasia, but that would be feeding the anemone. :p

[Sparkss]

The only thing I feed aiptasia is Joe's Juice :)