Jellies?

[Donya]

I added a couple mini-hermits to my 1 gallon yesterday to do some cleanup work on the rocks. This morning, in addition to a nice newly-cleaned tank, there are what for all I can tell are little jellyfish (or at least medusa-type coelenterate) cruising in the bowl. I took the filter out a while ago because it is close to burning out, so it's just airdriven circulation with a very gentle flow around the bowl. These little white/transparent guys a couple millimeters long with a bunch of short tentacles on the bottom drift around for a bit until they start to get close to the bottom, then they swim back up to near the top with typical jelly motion. I figure they must have been introduced with the hermits, since I see no way they would've gotten in there so fast otherwise and I would've noticed little dancing white blobs if they'd been there earlier with the amount of time I spend staring at the bowl. So...

- are these actually jellies?

- if they are jellies, are they doomed to die out in the setup I've got? I've read about really small species surviving...think there was a thread here at one point about it but I can't find it. The tank is currently home to a zillion sponges, bristleworms, those hermits I added, macro algae, some mushrooms, some zoos, and some white ball corallimorphs

-If they're not likely to be jellies, are they a larval form of something else I should expect to see popping up? I know some other coelenterates go through a medussa stage, I just thought it was microscopic


The books I've got don't describe anything like what I'm seeing in my bowl right now, so any help will be greatly appreciated

 

[SkiFletch]

Best I can offer you is that I've seen some posts around a few forums of people getting their tank FILLED with little jellyfish. It's pretty un-common, but can happen. You might have the same things. There was one such post I believe it might have been by Chac a while ago, but don't quote me on that.

 

[Donya]

I've seen some posts around a few forums of people getting their tank FILLED with little jellyfish.

erph....well, I'm starting to think that may be where my bowl is headed. I counted 3 total yesterday, now there's at least 10, probably more LOL. When they're not swimming, the settle on the macro algage tentacle-side sticking to it. I don't think there's anything in the tank they could harm, so I don't mind having them there. They're pretty interesting to watch.

 

[SkiFletch]

Yeah, sounds like the same ones. They explode in population but don't harm anything

 

[Danno]

Just wondering...
What do you have in your tank that could have carried these guys into your tank?

You had a tank journal correct?

 

[Donya]

I had a thread with the early evolution of the tank, but didn't document anything there, so it never really got to proper journal form lol. The most recent additions to the tank have been:
- a rock with zoos some months ago...not exactly sure when I put it in
- a mushroom rock a few weeks ago after most of the zoos got fried by digitate hydroids & the hydroids dissappeared
- 3 mini hermits to clean some fuzz off the rocks - added the day before the jellies showed up.

When I added the hermits, there was some bag water that escaped (I know...bad to do, but oh well). Since the jellies definitely were not visible prior to the hermits being added, I figure it must have come from the water that escaped in, although there was nothing visible in the bag water at the time. Maybe the came in as eggs/larvae? The hermits were from a LFS I don't usually go to because it's a bit of a drive, but I'm going to have to go back up there this week for some RO and will ask them if they've seen any similar things in their tanks recently.

 

[Donya]

Well...they're all still around and managing to find food I guess. Some have grown. My awful camera now picks them up as fuzz instead of them being invisible. The fuzz the arrow is pointing to is one of them sitting on the glass at the front:

http/img.photobucket.com/albums/v281/kwippo/jelly1.jpg
(excuse the background...I got sick of looking at my speakers through the tank)

They've taken to sticking on the glass a lot more, so I've gotten a better look at them. They've got 8 tentacles that are longer than I originally thought, some of which fork about halfway down. Tentacle span is about 0.5cm on most, closer to 1.0cm on the largest. It would be nice if they'd park themselves somewhere other than the glass, because now I can't clean the front and it's growing crud again

I did bring up the jellies with the LFS guys, but they havn't seen any mystery jellies. They have pretty heavy filtration though which would probably suck up any jellies after not too long. I havn't seen them in my 5 gallon so far, which also got hermits added from the same batch...but that tank's got a big powerhead in it.

 

[rictheredneck]

sorry for questioning your intelligence but are you sure they are jellies and not just copepods?

kinda hard to tell off the fotos...

 

[Donya]

Definitely not copepods--no hard parts, and the tentacles are quite obvious with a magnefying glass on the larger individuals. The pic was was just the first time I've ever been able to get one to even show up with my camera (which I should probably start using to take genuine loch ness monster pics, since the results are blurry enough ). They have radial symmetry and all the right internal anatomy visible for a jellyfish. The movement style is also the typical pumping movement that jellies have. The only strange thing that doesn't shout "jellyfish" about them is the fact that they swim for a while and then find someplace to sit flat with their tentacles splayed out. The resting behavior made me wonder if they were a larval stage of some other coelenterate, but they havn't changed.

 

[n3ont3tra]

This probably doesn't help much, but I have a story relating to jellyfish.

Last year my mom and I were on vacation in the Outer Banks, North Carolina. On the last day we were in the ocean and a jellyfish brushed up on my mom's arm. She said it hurt and then the pain went away. The next day she said it hurt again, and there was a rash. She looked up her syptoms and found that she had "seabather's eruption" and she said it was caused by jellyfish larvae. It hurt for about a week and a half. I have no idea where she found the info about seabather's eruption, or if she was just teasing me, but I figured I'd tell you incase it was true.

 

[Donya]

Oh man I hate the baby jellies that are all over some beaches I got covered in them once when I was a kid and the pain as the day went on was spectacular. I havn't put my hands in the tank since the jellies arrived in my tank, and I think I'll keep it that way LOL. The two largest jellies have quite the tentacle-span now. I'm just hoping they don't start stinging my shrooms and zoos. At any rate they jellies are happy, 'cause they just made a million babies. I don't know what they're eating in there but I guess there's plenty of it.

 

[Danno]

Smaller jellies normally have sticky tentacles to catch planktonic food. I don't know if this might help but I saw a documentry on jellyfish today and the smallest one that was shown is called a Thimble Jellyfish. Maybe yours can be along that line?

 

[Lynden]

I see a "boom and bust" scenario unfolding... have you considered feeding them zooplankton, et cetera to sustain the population?

 

[Donya]

I looked up the thimble jellyfish--looks a bit different. The smaller ones in my tank have short tentacles like that, but then they seem to grow a set of really long sweeping ones as they get bigger. I also don't see the same coloration present on mine.

I see a "boom and bust" scenario unfolding... have you considered feeding them zooplankton, et cetera to sustain the population?

I've been wondering about the population of them in there. I have some frozen zooplankton that I could try and see if they eat it; havn't tried thus far but might give it a go this evening.

 

[Donya]

The plankton stuff seems to work for the big jellies, not so for the smaller ones. I got some finer food today that the baby jellies should be able to eat better. My small zoos seem to like the smaller particles better too.