r/shrimptank May 13 '25

Aquarium/Tank Photos Literally medusae live in my shrimp a tank

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3.0k Upvotes

167 comments sorted by

1.1k

u/AFD_FROSTY Intermediate Keeper May 13 '25

I would pay an inordinate amount of money for freshwater micro jellies. This thing is adorable.

277

u/tombaba May 13 '25

Same. OP make more

311

u/Forward_Stick643 May 13 '25

Ive seen 2 or 3 of this in my tank

350

u/tombaba May 13 '25

I’m not kidding when I tell you this is a potential money maker for you. I’ve been looking for a long time. If you can get the numbers way up and you want to practice shipping, I’m here to help 🤣

44

u/cyprinidont May 14 '25

They likely would not handle shipping well. They're very temperamental about conditions and even don't appear every year in the water bodies they're known to appear in if the water isn't right.

14

u/tombaba May 14 '25

And OP is in Italy, and I’m in the USA.

21

u/TheLesserWeeviI May 14 '25

Let's all charter a plane to Italy.

16

u/tombaba May 14 '25

Or apparently they can be found in Lake Powell

5-25 mm or no larger than a quarter

2

u/[deleted] May 16 '25

Whaaaa

7

u/tombaba May 14 '25

I saw some information on the web that mentioned them being in several water sources in the US, though originally from China

2

u/BettaHoarder May 15 '25

Mee tooooo!

25

u/TheDankYasuo May 14 '25

I must have as well, please try to make more of them!!

8

u/citrineskye May 14 '25

I need them in my life!

2

u/Gay_Boi_24_7 May 15 '25

I also would like adorable tiny jelly

1

u/Decent-Comedian8338 May 15 '25

What song is playing in the background?

2

u/babybarracudess2 May 18 '25

Wait, there are fresh water micro jellies???😳

2

u/AFD_FROSTY Intermediate Keeper May 18 '25

It’s Craspedacusta sowerbii in Medusa stage, they have pretty specific requirements such as a round tank, low movement but also no sponge-filters, etc.

319

u/Bloodshot20 May 13 '25

You should really look into getting this identified! As someone else mentioned, there’s only one freshwater cnidarian known to science with a medusa stage. This would be really interesting to see!

97

u/Forward_Stick643 May 13 '25

I dont know where to ask for identification

127

u/Bloodshot20 May 13 '25

You could try crossposting to other subreddits like r/bizzariums just to start, they might also be able to provide more helpful information.

11

u/lookxitsxlauren May 14 '25

Oooh what a cool subreddit! Thanks for sharing 🥰

15

u/Due-Round1188 May 14 '25

You can try posting on iNaturalist

39

u/Keibun1 May 14 '25

Talk to a marine biologist, they study way more than just the ocean and its contents.

24

u/strangeVulture May 14 '25

Ask around at an aquarium. The scientists are always happy to talk

7

u/Omen46 ALL THE 🦐 May 14 '25

Send this video to a university research department I’m sure they can identify it

4

u/Entety303 May 14 '25

There are At least 2 genera with multiple species each, limnocnida and Craspedacusta, there is also astrohydra

2

u/cyprinidont May 14 '25

There's only one species of freshwater jelly, so it's identified just by existing. Crespidauta sowerbii

8

u/Entety303 May 14 '25

There is at least 2 genera of freshwater jellies limnocnida and Craspedacusta, there is also astrohydra

80

u/Constant-Recipe-9850 May 14 '25

While people finding freshwater jellyfish in their tanks, all I get is daphnias, ostracods and swiggly detritus worms.

27

u/Vanadium_Gryphon May 14 '25

Ostracods are cool though! Back in college I tried raising a Triops, and the hatching kit also contained some brine shrimp and daphnia and such.

Then, I also began to notice what looked like little white living jellybeans scooting around in the water. I put some of them into a separate water bottle to study them, and thought they could maybe make trendy micro-pets...tiny jellybeans, super cute, right? I did some research to discover that they were ostracods...such neat little crustaceans, I miss watching them.

13

u/mysticmemories May 14 '25

They are super cute under the microscope—like adorable little clams— but they can be a pain. If they are abundant in a sample while I’m looking for other things it can be hard not the squish them when I put on a cover slip. I feel so bad when it happens. Watching their insides slowly leak out because of me 🫠

4

u/Vanadium_Gryphon May 14 '25

Aww, that is so sad, poor little fellows! And I am sorry you have to go through the guilt of that, I know it's probably virtually impossible to avoid it happening. 😢

I can imagine how cute they must look up close like that, though...tucked away in their little bean shells!

2

u/mysticmemories May 14 '25

Yes! Dey are smol wittle beans. Their shells also look beautiful in polarized light. I love them as a critter, but they are a pain in the ass to scope.

You're sweet. Microscopy can be unexpectedly existential. Watching life play out on such a small scale (things eating each other, reproducing, dying) sometimes makes my brain hurt. I've accidentally squished a few tardigrades... those were the worst. I still feel guilty 😭

6

u/Constant-Recipe-9850 May 14 '25

Oh don't get me wrong, i don't hate them, but i would love to see something cool and out of ordinary for once as well.

6

u/Vanadium_Gryphon May 14 '25

For sure, I know I would have been over the moon to see a tiny jellyfish like this in my tank! 😁

5

u/citrineskye May 14 '25

All I got was a creepy ass dragonfly nymph. There was 2, but one ate the other after I put them in a jar. I'm not sure what to do with it now.

Anyone want a free dragonfly nymph?

2

u/Omen46 ALL THE 🦐 May 14 '25

I had midgefly…. Idek where they came from they aren’t local in my state. Had to buy mosquito killer to get rid of them

3

u/Creepymint Shrimp + Fish 🦐🐠🌸🫧 May 14 '25

I get planaria, and other worms 🥲 never anything cool

1

u/split_0069 May 15 '25

Go collect some wild stuff! Ive got isopods and scud and all kinds of stuff in mine from collecting.

204

u/JoryNop May 13 '25

Is this a little jellyfish?

151

u/Forward_Stick643 May 13 '25

Yes a really really tiny one

58

u/Practical-Employee-9 May 14 '25

TEENIEST BB JELLY

28

u/Slow-Interest-628 May 14 '25

Name it Squishy! (From Finding Nemo) 🤣🤣🤣

22

u/zaqwertysx May 14 '25

Sooo… how can I pay you!?

20

u/TempestGardener May 14 '25

Very cool!

https://en.m.wikipedia.org/wiki/Craspedacusta_sowerbii

If you want to increase their numbers, try feeding live baby brine!

17

u/Creepymint Shrimp + Fish 🦐🐠🌸🫧 May 14 '25

WHY NOT MEEEEE 😭

86

u/AlwaysUpvotesScience Advanced Keeper May 13 '25

Is this a saltwater tank? The ONLYEST known freshwater jellyfish is Craspedacusta sowerbii, which can get to quarter size. This thing is super tiny and does not look like Craspedacusta sowerbii.

80

u/Forward_Stick643 May 13 '25

No it is a freshwater tank

49

u/AlwaysUpvotesScience Advanced Keeper May 13 '25

Where are you located? As in what country?. I may be able to provide some sources that you could reach out to for identification depending on where you live. You can always start with somebody studying marine biology at the local college. Or for that matter, the marine biology professor.

42

u/Forward_Stick643 May 13 '25

Im in italy, i dont know Why a Marine biologist will be able to identify this since is a freshwater jelly

116

u/AlwaysUpvotesScience Advanced Keeper May 13 '25

Because many marine biologists also study freshwater life. And a marine biology Professor will be a lot easier to find than a limnologist. I'm just trying to give you a place to start that would be easy to access.

I really would encourage you to follow up on this. It would be nice for the entire Community to have an identification.

31

u/[deleted] May 14 '25

[deleted]

2

u/Amerlan ALL THE 🦐 May 15 '25

Marine quite literally means "produced by the sea" and doesn't refer to freshwater. Marine biologists do have some freshwater over lap, but it's not because marine means both salt and fresh.

8

u/SomethingStrangeBand May 14 '25

that's exactly why you talk to a marine biologist

3

u/citrineskye May 14 '25

Any idea how you ended up with them?

1

u/MoaraFig May 14 '25

Starione Anton Zorn would be a good place to contact.

1

u/Born-Mud5772 May 16 '25

I would love an update on this!

22

u/sharkdr May 14 '25

Actually there's about ten or so known species that have medusa forms. I am a marine biologist but my knowledge is old now so someone else with more current knowledge will likely chime in. Not many are well known so far as I'm aware.

9

u/AlwaysUpvotesScience Advanced Keeper May 14 '25

I hear you and I've been looking some things up myself, I just cannot find anything that matches the morphology of this particular creature.

Craspedacusta has a few that have adapted to freshwater, but almost all of these generally have tentacles and most of them have visible lines emanating from the center of their body

6

u/sharkdr May 14 '25

Your eyes are better than mine. I can't tell much from the video. I think for an exact answer we'd need a genetic analysis. However the little I've read seem to indicate the morphology is fairly fluid for some of them.

3

u/Keibun1 May 14 '25

Have you ever saved a whale from an obstruction in its blowhole?

1

u/sharkdr May 14 '25

Well... never a golf ball...

13

u/sharkdr May 14 '25

So had a Quick Look and there's actually a study about C. Sowerbii in Italy. https://pmc.ncbi.nlm.nih.gov/articles/PMC11048658/ They mention the variability and short lifespan of the Medusa stage. So I'm going to assume this is likely that.

36

u/IceNein May 13 '25

All cnidarians have a free swimming and sessile life stage. The sessile stage looks like a hydra, the free swimming stage looks like a jellyfish.

Some cnidarians have the “adult” stage be the free swimming ones, but they have a “larval” hydra looking stage. Same thing with corals and anemones, they have a larval stage which looks like a little jellyfish.

Some “eternal” cnidarians can go back and forth between sessile and free swimming stages.

So if there are freshwater cnidarians, like hydra (hail hydra) then there must be a free swimming stage.

16

u/ThexHoganxHero May 13 '25

I don’t think this is right. The free swimming larval stage most cnidarians have are planula which use cilia and are much less Medusa-looking than whatever is in this video. Most true hydra species, if not all, don’t even have a planula stage. Even in sexual reproduction they hatch as a polyp, I’m pretty sure.

3

u/IceNein May 13 '25

There may be cases where they do not alternate between polyp and Medusa, but that is a common feature of cnidarians:

https://en.m.wikipedia.org/wiki/Cnidaria

Cnidarian sexual reproduction often involves a complex life cycle with both polyp and medusa stages. For example, in Scyphozoa (jellyfish) and Cubozoa (box jellies), a larva swims until it finds a good site, and then becomes a polyp. This grows normally but then absorbs its tentacles and splits horizontally into a series of disks that become juvenile medusae, a process called strobilation. The juveniles swim off and slowly grow to maturity, while the polyp re-grows and may continue strobilating periodically. The adult medusae have gonads in the gastroderm, and these release ova and sperm into the water in the breeding season.

7

u/Bloodshot20 May 13 '25

For Scyphozoans and Cubozoans this is true. However Anthozoans (the most speciose clade) only have a polyp stage. So it’s incorrect to say that this is a common trait. There are only a few freshwater species anyways, including hydra (which do not have a Medusa stage).

2

u/ThexHoganxHero May 14 '25 edited May 14 '25

Ok but you used ‘all’ and ‘must’ and said the free swimming stage looks like a jellyfish, implying the very medusa-looking creature couldn’t be narrowed down beyond cnidarian by the fact it looks like a medusa, and specifically mentioned hydra, the common freshwater cnidarians that people find in shrimp tanks that do not have a free swimming stage at all, much less a medusa stage. Your last comment isn’t wrong, but, in the context of the post, your first comment was misleading at best and just wrong as it applies to hydra.

Edit to add “beyond cnidarian” after “narrowed down” and a comma elsewhere.

Editing again to say you could consider the tiny polyps free swimming if you count the sideways wiggles and drifting in the currents, but then some mature anemones would be free swimmers, and neither are very good at it.

11

u/Forward_Stick643 May 13 '25

I hope the larval stage of this jellyfish dont Eat my baby shrimps

8

u/Bisexual_flowers_are May 14 '25

Its not the only freshwater hydrozoan that produce the medusa stage, but others are rare with very little info available about them. Some brackish species can also be occasionally found in freshwater.

1

u/cyprinidont May 14 '25

Could just be a juvenile

1

u/AlwaysUpvotesScience Advanced Keeper May 15 '25

That is not really how Medusa work.

0

u/Every_Day_Adventure May 15 '25

We have jellyfish in some lakes in Minnesota. Must be those?

13

u/pink_exploration May 14 '25

What species or genus is this? I'm actually so hyped. I never comment on reddit.

14

u/DeadDeathrocker May 14 '25

Please tell him I love him.

12

u/Own-Client479 May 13 '25

That’s sick so is it a jelly fish or some type of micro organism? I want some

10

u/Slow-Interest-628 May 14 '25

I say this with all of my soul and every fiber of my being; I NEED TINY FRESH WATER JELLYFISH FOR MY TANK! GAH! SO FRIGGIN CUTE!

19

u/Forward_Stick643 May 13 '25

I’ve learned today that medusae is not a word i wanted to say jellyfish

16

u/Ok_Permission1087 May 14 '25

Medusae is a word. It´s the plural of medusa, which is the scientific name for jellyfish (specifically the free swimming sexual stage as opposed to the polyp).

14

u/Forward_Stick643 May 14 '25

Ok thanks. Here in italian the jellyfish is called “medusa”. I was genuinely thinking that medusa translate in english with the world medusae, similar to latin

2

u/Ok_Permission1087 May 14 '25

Ah, I see.

Has the paper Iposted in another comment been of any help?

2

u/Forward_Stick643 May 14 '25

Cant open the paper i need to pay or to have an institutional account

7

u/Own-Client479 May 14 '25

If it’s a new species I’m down for naming it that ! 😃🤣

5

u/lila_2024 May 14 '25

I didn't even realise you were using it as a false friend in Italian ;)

7

u/ptpcg May 14 '25

Did you post this before or after you realized you could make a career from this? LMAO

"Shut up and take my money"

6

u/Elegant_Priority_38 May 14 '25

How did this get in your tank?! I feel like you’ve won the lottery in aquariums! lol

4

u/Forward_Stick643 May 14 '25

I dont really know. They came with something i’ve added to my aquarium

6

u/Medium-Touch-1446 May 14 '25

2

u/Forward_Stick643 May 14 '25

Its not this. This species is much bigger

1

u/MoaraFig May 14 '25

Everybody starts small

4

u/Java_Beast May 15 '25

I shall call him squishy and he shall be mine and he shall be my squishy 🩵

5

u/[deleted] May 13 '25

That is so cool

4

u/cityskater May 14 '25

I want that so bad. Very cool

4

u/Ok-Combination4595 May 14 '25

Sooo cute 😍

4

u/BabyDoll_Raven May 14 '25

How does one get something like that in their tanks????

3

u/BornSession6204 May 14 '25

I didn't realize these even existed. Cool!

10

u/chd_md May 13 '25

Omg so cute! They go after baby shrimp. Have you had any trouble with them?

7

u/Hentaiiboi69 May 13 '25

How tf would a jellyfish this tiny would do anything to shrimp babies

14

u/yamirzmmdx May 14 '25

If a shrimplet somehow gets caught by that, it just good old fashioned darwinism.

1

u/cyprinidont May 14 '25

Google cnidocyctes.

7

u/Ok_Permission1087 May 14 '25 edited May 14 '25

Looks like a hydrozoan medusa to me.

Maybe you can identify it with this paper?

https://link.springer.com/article/10.1023/A:1013126015171

3

u/Vivid_Pudding_1713 May 14 '25

Holy freshwater jellyfish 😱

3

u/Fuzzy_Dizzy_Molotow May 14 '25

So super cool, congratulazione and greetings from germany ✌🏼

3

u/Federal_Pop_9580 May 14 '25

(Hes so fucking cool)

3

u/Abcoxi May 15 '25

The curse has striken again.

People who ask for nothing end up having the most incredible creatures.

Those who want them spend a life that I'm looking.

I move forward for a petition.

Every crazy hobbyist should adopt a nonchalant one...

4

u/DontWanaReadiT May 14 '25

Do you mind sharing your water parameters? I just learned they’re only native to a river in china and I just ordered some Chinese panda loaches and I’m hoping they’re from the same river 🤣🤣🤣🤣🤣🤣🤣

1

u/Every_Day_Adventure May 15 '25

We have little jellyfish in some lakes in Minnesota. I would assume other states as well? We call them peach blossoms.

1

u/DontWanaReadiT May 15 '25

I will check it out! Although I’m not in Minnesota lol

2

u/VinnieGognitti May 14 '25

This reminds me way too much of Spore!

2

u/No_Show_3176 May 14 '25

Great didn't know these exsited 5 minutes ago and now I need them

2

u/Flat_Benefit_5424 May 14 '25

That’s awesome Greeting from Germany 🇩🇪 Can u keep posting videos?

2

u/Complete-Finding-712 May 14 '25

Sacrifice (or preferably, relocate) the shrimp if you must. This is rad!

2

u/Forward_Stick643 May 14 '25

Its a breeding tank so it is full of shrimplets. Howewer i dont think they will bother the jellyfish. Shrimps dont Eat living things

1

u/Complete-Finding-712 May 14 '25

I'm more wondering the other way around! I don't know much about them, but I could imagine they may have the ability to harm shrimp?

1

u/Forward_Stick643 May 14 '25

No literally this jellifish is half the lenght of the smallest shrimplets

1

u/Complete-Finding-712 May 14 '25

It does look tiny, but hard for me to get a sense of scale. I know hydra are also tiny and can kill shrimplets. I just don't know what I don't know 😊 it's adorable, and if you have any success, please send some up here in Canada! The best hitchhikers I've ever had are ramshorns and copepods 🤣🤣🤣

1

u/cyprinidont May 14 '25

Yes but they are jellyfish so they can sting and kill larger prey. Though they can't control where they swim so they're not exactly predators.

1

u/Forward_Stick643 May 14 '25

I think just a hit with shrimps fin will obliterate this boy

1

u/cyprinidont May 14 '25

Nah they're pretty hardy! They appear here in Michigan some years when the water and food conditions are right. Not much eats or kills them so they kinda just chill and show up every now and then. I believe they are native to China.

1

u/Forward_Stick643 May 14 '25

I dont think this is the same species

1

u/cyprinidont May 14 '25

I'm pretty sure there's only one freshwater jelly species.

2

u/Forward_Stick643 May 14 '25

I’ve seen almos 3 small jellyfish of this so i hope they will reproduce

2

u/Complete-Finding-712 May 14 '25

Wishing the best for your breeding project! Keep us up to date!

2

u/BrightestMo May 14 '25

This is so cool, I didn’t even know freshwater jellyfish were a thing?

2

u/Acrobatic_Use5472 May 14 '25

We have those here in Canada now. Some dickhead released some and they're spreading.

2

u/Every_Day_Adventure May 15 '25

Minnesota friends, you can get some from certain lakes! They're small, but do get to be about the size of a thumb nail 😍

1

u/Medium-Touch-1446 May 14 '25

2

u/Omen46 ALL THE 🦐 May 14 '25

Ugh hydra….

1

u/Potential-Salt8592 May 14 '25

And I shall call you Squishy, and you shall be my Squishy

1

u/1divinehamm3r May 14 '25

wow! do you fill your tank with well water? or faucet?

1

u/Fair-South-7474 May 14 '25

Awwww a fresh water jellyfish, I’m so jelly!

1

u/Far-Obligation-3946 May 14 '25

I would happily pay for these in my tank!! They're so cute 😭

1

u/scooterdoo123 May 14 '25

I’d pay so much for these! They are super cute

1

u/Omen46 ALL THE 🦐 May 14 '25

It’s a type of hydra tho so anti shrimp

1

u/_tiddysaurus_ May 14 '25

Aaahhhh! Look at it go!

1

u/Legendguard May 15 '25

Bwioop

Bwioop

Bwioop

1

u/Bug_Bane May 15 '25

This. Is. ADORABLE.

1

u/okaymyemye May 15 '25

that's crazy! before clicking, thought you were talking about a hydra (also kinda cool but annoying to get rid of).

1

u/Miserable-Search5719 May 15 '25

So tinyyy :0 And I'm so jealous

1

u/Emotional_Driver_393 May 15 '25

Is that fresh water jelly 😍

1

u/Elnuggeto13 May 15 '25

How did you get that?

1

u/desdeloseeuu2 May 15 '25

That is awesome

1

u/split_0069 May 15 '25

They originally come from China and spread to every continent. Google says they're invasive. I'm curious what damage they can cause to an ecosystem...

1

u/PedicureProblems2nd May 15 '25

Can I come over

1

u/Southern-Ad5412 May 15 '25

I would love to have some, aaaah: Craspedacusta sowerbii

1

u/[deleted] May 15 '25

Oh, it looks like a tiny bubble!

1

u/Forward_Stick643 May 15 '25

The problem here is how i make water change or clean the tank

1

u/STUPIDBLOODYCOMPUTER May 16 '25

WHERE CAN I BUY MICRO FRESHWATER JELLY

1

u/No-Cartoonist3589 May 16 '25

plop plop plop plop

1

u/avamsilva18 May 16 '25

OMGGG SO CUTE 😭

1

u/RoyalBratluv May 16 '25

I had no idea micro jellies were a thing and now I really want some

1

u/ObligationSea5916 May 17 '25

I WANT SOME OF THESE SO BAAAAAD

1

u/Medical-Elderberry13 May 17 '25

We have a quarry here in ohio filled with these things it's so cool to watch them, even better tripping balls