onlyreefers
Community Member
I have some sort of new creature on my glass. It is small, circular and pink. It constantly pulsates, in a contracting, circular motion. Glanced over the hitchikers guide and did not see anything similar.
Pulsating pink jelly-like creature
- Thread starter onlyreefers
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EeyoreIsMySpiritAnimal
Just another girl who likes fish
Medusa form of a hydroid, probably. How old is your tank?
onlyreefers
Community Member
This setup is 6 weeks old.
EeyoreIsMySpiritAnimal
Just another girl who likes fish
These are very common in new tanks and will go away on their own soon
onlyreefers
Community Member
Thanks! Just never seen or heard of anything like it
EeyoreIsMySpiritAnimal
Just another girl who likes fish
You're going to find all kinds of cool stuff
Alexraptor
Well-Known Member
I'ts really hard to tell from those pictures, but is it laying loose on the sand, pulsing with frilly bits/tentacles pointed towards the sky?
Because I almost think it looks like an upside down jellyfish, Cassiopeia sp.
Because I almost think it looks like an upside down jellyfish, Cassiopeia sp.
onlyreefers
Community Member
I don’t know about how loose. Thought about poking near it to see if it moved. Started on the glass and has been resting in the sand since. It’s typically stationary. I never spot it moving.
I did take a google search of the upside down jellyfish, and it looks like that’s exactly what it is!! Thanks!
Do they sting corals, people, fish? Seeing that they are typically sand resters on the search.
Alexraptor
Well-Known Member
Then congratulations are in order, one of the more unusual hitchhikers!
To answer your question, they are known to have a mild sting, strong enough to produce an itchy rash on human skin. But it's purely defensive, they don't have long trailing sweepers like more predatory jellyfish do. Instead they feed like photosynthetic corals, and spend most of their time on the bottom, soaking up the light for their zooxanthallae.
Personally i'd risk keeping it, as it's one of very few jellies that can actually be kept in a normal tank.
onlyreefers
Community Member
All new ones just float over into their little spot with the others and never move. They are always stationary and the livestock never try and nip at them or anything.
Alexraptor
Well-Known Member
They are actually extremely delicate and don't like being blown around by strong currents and can even be damaged if thrown against the rocks. My guess is that spot is an ideal sweet spot in your tank, for them.
Eventually though you may need to rehome them, as they can grow to the size of a dinner plate, and with 16 individuals? Well....
Honestly a bit envious.
GlassMunky
2500 Club Member
This looks like pulsing Xenia to me not jellyfishUpdate. I now have 16 of them lol
onlyreefers
Community Member
Thanks! I saw that they can get at least 2-3”, dinner plate would be great lol. The largest one seems to have stopped at about 2 inches. It seems like at least 1 new baby per week. I’ve got some local reefers I can give the extra to if things get crazy, and a little cycling 25g setup that I could dedicated for them. I’m a big fan. Fun to watch.They are actually extremely delicate and don't like being blown around by strong currents and can even be damaged if thrown against the rocks. My guess is that spot is an ideal sweet spot in your tank, for them.
Eventually though you may need to rehome them, as they can grow to the size of a dinner plate, and with 16 individuals? Well....
Honestly a bit envious.
onlyreefers
Community Member
They are 1000% upsidedown jellyfish. If I were to disturb the sand a fluff them up into the air (water column), they will “swim” once in lifted up, and you can see their full jellyfish body.
