Cassiopeia/upside down jellyfish - how big will they get?

pixelhustler · Mar 20, 2022

I bought some live rock with these jellyfish attached in the polyp stage. I overfeed frozen food so they quickly spread out through my tank as they’re able to reproduce in the polyp stage without completing the cycle as Medusa.

I’m wondering if anyone has an ID on the particular species and can tell me how large they will get? I put a bunch of them in a breeder box and they have slowly grown to 1/2”. Would love to set up an aquarium for them if they end up growing as large and colorful as I’ve seen on some images. I’m attaching my jellyfish and pictures of what I’m hoping for.

bradleym · Mar 20, 2022

I don't have any info to offer, but I find these very interesting. Can you provide any other pictures, perhaps with a flash camera or with white lights on them? Usually these hitchhikers turn out to be a type of hydroid, but these look different.

evrydayzawrkday · Mar 21, 2022

This is amazing.

pixelhustler · Mar 22, 2022

bradleym said:
I don't have any info to offer, but I find these very interesting. Can you provide any other pictures, perhaps with a flash camera or with white lights on them? Usually these hitchhikers turn out to be a type of hydroid, but these look different.

I’m sharing some more images. I wonder if they will grow to be 8 inches like the ones Liveaquaria sells because mine are growing super slow. I’m thinking of getting a nano with an AI Prime just for them. Just not sure if I want to take on extra work.
I read they live off the coast in Florida (where my live rock came from) and the Caribbean, and someone said they can be kept at room temperature as they’re pretty hardy.

bradleym · Mar 22, 2022

These are one of the coolest hitchhikers I've ever seen! Thank you for sharing.

Nick Steele · Mar 22, 2022

If that’s a true upside down jelly that is awesome!!!

I see them all the time off Florida’s east coast when fishing in shallow waters or snorkeling and diving.

Eagle_Steve · Mar 22, 2022

pixelhustler said:
I’m sharing some more images. I wonder if they will grow to be 8 inches like the ones Liveaquaria sells because mine are growing super slow. I’m thinking of getting a nano with an AI Prime just for them. Just not sure if I want to take on extra work.
I read they live off the coast in Florida (where my live rock came from) and the Caribbean, and someone said they can be kept at room temperature as they’re pretty hardy.

If they are Cassiopea xamachand and came to you via live rock from Florida, they can get up to 6"-8" or so.

I currently have 3 of them that are about 2.5-3" at the moment. They are tricky to keep in a DT, as they can swim to get to a spot they want. They can also easily get down an overflow if not setup properly. My 7' macro/mangrove lagoon now has cross stitch mesh over the weirs, so they cannot go down the overflow. This requires me to clean it at least twice a week. I also have to run it around my gyres and can only run the flow not as much as I would like.

They are usually best in a species only tank where filtration can be done via something with a sponge cover and minimal flow. But if one took the time and effort, they could go into a reef tank.

Here are my little ones in their eggcrate area before I made the changes to the gyres and overflow.

pixelhustler · Mar 22, 2022

Eagle_Steve said:
If they are Cassiopea xamachand and came to you via live rock from Florida, they can get up to 6"-8" or so.

I currently have 3 of them that are about 2.5-3" at the moment. They are tricky to keep in a DT, as they can swim to get to a spot they want. They can also easily get down an overflow if not setup properly. My 7' macro/mangrove lagoon now has cross stitch mesh over the weirs, so they cannot go down the overflow. This requires me to clean it at least twice a week. I also have to run it around my gyres and can only run the flow not as much as I would like.

They are usually best in a species only tank where filtration can be done via something with a sponge cover and minimal flow. But if one took the time and effort, they could go into a reef tank.

Here are my little ones in their eggcrate area before I made the changes to the gyres and overflow.

That’s so cool! A mangrove & macro tank is a great idea. If they grow I think I’ll start a nano like that. Do you have a thread with more pictures of your tank?
Are they growing pretty slowly too? My rocks are covered in polyps and I recently learned they can reproduce asexually in the polyp stage. The polyps spawn medusa consistently but they get sucked into the sump and die. It wasn’t until I put some in a breeder box that I saw them grow, albeit very slowly.
Also, what do you feed or do you rely on light/photosynthesis?

Eagle_Steve · Mar 22, 2022

pixelhustler said:
That’s so cool! A mangrove & macro tank is a great idea. If they grow I think I’ll start a nano like that. Do you have a thread with more pictures of your tank?
Are they growing pretty slowly too? My rocks are covered in polyps and I recently learned they can reproduce asexually in the polyp stage. The polyps spawn medusa consistently but they get sucked into the sump and die. It wasn’t until I put some in a breeder box that I saw them grow, albeit very slowly.
Also, what do you feed or do you rely on light/photosynthesis?

My build thread badge is the link. If you click it, it will take you there.

I rely more on photosynthesis for them, but mysis for the fish does get caught by them. So far, they are growing slowly and prefer around 500-600 par. At least that is the par at where they sit. I use full spectrum led grow lights on that tank, as the mangroves and macro love tons of light.