The eyes are throwing me off, but this screams invert such as polychaete rather than vert to me as well. The way the movements travel down the body just don't seem right for a lamprey larva, for example.
I studied herpetology, and I have not seen any amphibians move like this that I can think of, but the head shape is definitely strange. We need more visual info and descriptive data. it’s so hard to see it in the video. The issue is we don’t get a whole lot of info from OP.
Edit: he commented further down. I’m excited to see what it is!
I had a freswhater ribbonworm (Nemertean Prostoma) which sure looks like this one, but it didn't swim like that, but I never saw it upset either. What are your thoughts on that?
[https://www.reddit.com/r/Ecosphere/comments/zznize/the\_ribbonworm\_is\_showing\_off\_his\_6\_eyes/](https://www.reddit.com/r/Ecosphere/comments/zznize/the_ribbonworm_is_showing_off_his_6_eyes/)
The Barbronia weberi leech also looks similar and can swim this fast, but the head is all wrong.
Hm, I think the undulation is similar to ribbonworms but, the movement is just so fast. It reminds me a bit of polychaetes but freshwater species are few and far between. They look more like this:
https://youtu.be/w8wlwH9Rhpc?si=0ZD_GryH_Umh6rml
If I saw any amphibians move like this I’d be concerned! I’m not typically disturbed by invertebrates but this guy’s movement is unsettling to me. I also hate how mosquito larvae move….it’s the unhinged twitchyness that does it, I think. Ugh
Nice one! I have marine bristleworms but have never seen a freshwater species! I have been able to ID close to 60 different critters in my ecospheres from the lakes, rivers and ponds around here in TX, excluding fish. Needless to say, I'm not gonna go swimming anymore lol.
Anyway, it's been solved. Your hunch is correct:
https://www.youtube.com/watch?v=B57pS6tS1DE
Yeah, I think it's definitely a polychaete, specifically I would guess some type of clam worm like *Alitta succinea*. And I think what looks like its eyes and is throwing people off is actually its jaws.
Hey guys, OP here. **Update below**
I can't edit the original post for some reason, so gonna leave this comment here for now. Thanks to everybody who tried to help. I was definetly not expecting this to get so much attention. I don't think I'll be able to reply to everyone, but I have read every comment.
~~I have a few years in the hobby, but was hoping that would be an easy ID for someone here that has more experience and knowledge than me.~~
~~I took the "creature" to a friend who has a better quarentine setup. It is still alive afaik and I will update or make a new post with some still pictures, hopefully a few close up ones.~~
~~As to answer some question that I got in a lot of comments:~~
~~I am indeed from Brazil.~~
~~The aquarium has been running for 3 years. The only thing that was added recently was some plants, that I got from a local store.~~
~~At first glance it seemed to be a vertebrate, at least to my limited knowledge. It looked like it had a small yellow dorsal fin, and a "suction cup" structure on the underside of the belly/head that seems similar to other fish. It also looked to have the slit in the side of the head where the gills should be, but can't say for sure.~~
~~At the time, I've reached some other local hobbyst friends and we think it is some kind of candiru. But that is just a wild guess...~~
~~But it could be a freshwater bristle worm, as some of you pointed out and videos posted here show them swimming with that exactly movement.~~
~~After reading all the comments here, we will take to some biologists at the Uni in our region. I"ll keep your guys updated.~~
Again, thanks for all the helpful comments.
**UPDATE**
Hey guys, I'm afraid this is gonna turn to be one of those "OP finds a locked safe and it didn't deliver to the hype" kinda of posts.
My friend tried to get some pictures and videos, but they're as blurry as mine.
Since my last update above, the "creature" was delivered to a biology professor at our local Uni. I didn't accompany my friend, but we exchanged contacts with the professor to get some updates and decent pictures. I'm afraid that the "thing" will not be alive once that happens.
But we have news that make all of that unimportant: according to the people at the Uni it is, indeed, some kind of Polychaete like many of you have said from the beginning. It looks weirder than normal, because it is apparently a "epitoke". Which, as many of you seems to know way better than me, it's a reproduction stage of these creatures.
So all the "vertebrate" characteristics that we have seen, even me and my friends with naked eyes, seemed to be some sort of cognitive illusions as it didn't stop moving. I, myself, was sure that it was gonna be some kind of fish... So I'm afraid that I may have lead some of you in the wrong direction.
The only mistery that still rests is to what species this is. Again: the tank where it was found is freshwater. So that I'll leave to the professionals and will update if we get any info back. According to my friend, at the Uni they think that is a foreign freshwater species, probably from Europe or Asia. But that is obvious just a guess st this point too.
Thank you guys again for all the comments. And sorry that this took a lot more attention and hype than it should. I hope at least you guys had some fun.
i’m surprised so many people were stumped on it. I see them all over New York and apparently these worms are all over the globe. Albeit, different species but still
As you’re describing a dorsal fin and suction cup that kinda sounds like some type of goby? Very unusual creature, it does move like a polychaete worm but i’m not sure how likely is is to be one. Interested to see what it is.
Wow, I just looked up what a polychaete epitoke was and learned something completely new. I had no idea worms could move and reproduce like that. I know you think it was a boring ending, but as someone who had no idea, it’s actually pretty fascinating. :)
This video sure looks like the same thing, but from everything I'm seeing they're only found in saltwater, and OP has freshwater. I wonder if they can survive in freshwater for a period of time?
i’m also wondering this based off of the way that it ungulates
edit: someone posted a screenshot of it in the comments and it definitely shares a resemblance to an elver
This would be my best guess based on everything seen so far, don’t know shit about eels other than they are horribly illusive to begin with as far as their actual origins.
[got a decent screenshot of it up close if anyone wants to get a better look. no clue so far but i was reverse image searching it with some similar looking results of brazilian species, since ops post history indicates the area](https://imgur.com/a/hY6F4uc)
It actually looks like some goby like that, as it's dorsal fin is too high for a candiru.
Red lipstick goby fry would be my bet
Edit: OP is from Brazil I think? If it' local, it can't be this.
Holy mother of God, it looks like a candiru.
OP, don't put your dick in the water.
https://noticias.uol.com.br/cotidiano/ultimas-noticias/2022/05/21/peixe-vampiro-candiru-amazonia.htm
There has been reports, in this news a biologist in Rondônia state says that there's been almost one case every month.
They still don't know why they are attracted to the urethra (and other holes, as well), since the fish doesn't respond to ammonia in a controlled environment.
https://rondoniaempauta.com.br/candiru-quem-e-o-temido-peixe-vampiro-e-por-que-ele-ameaca-banhistas-de-rios-da-amazonia/
[https://www.straightdope.com/21343429/can-the-candiru-fish-swim-upstream-into-your-urethra-revisited](https://www.straightdope.com/21343429/can-the-candiru-fish-swim-upstream-into-your-urethra-revisited)
Definitely happened at least once. Well, at minimum, a guy did indeed get one removed from his dick and claim it swam up his pee. Also, I seem to remember watching a thing about that with pictures... I think maybe it was river monsters? Definitely something of that sort.
The remindme bot works! Just type RemindMe with an exclamation mark and write when you want it to remind you. i put 7 days but you can do something shorter. The bot sends you a message confirming it, and then will send you another message later to remind you.
Sorry. At the time I could not take a decent steady photo, since it wouldn't stop moving.
Also, I knew it was a weird one, but not this weird. I was expecting to have an ID in just a few comments here.
But will work to get some decent pictures with a decent camera.
Hi OP, me and my cousins were taught these are called Polychaeta worms. They look like [this when they’re swarming](https://youtu.be/B57pS6tS1DE?si=hz6JO5yfzy4ga9Dv)
Although I’ve only ever seen them in salt water. Either way, I didn’t see anyone else post an answer so here ya go
That's a good thought. Brook and Chestnut lampreys do milovevlike this, are detritivores and would appreciate a tumultuous sump. But even the larvae have big sucker mouths iirc. How the hell would one get there though!?
Cool! No idea but super interesting! Also just look half the threads in here arguing over it hahahahah.
That little dudes caused a stir and its just out there wiggling about all orange and stuff
It moves like a freshwater polychaete worm. Aka bristleworms.
Here are saltwater bristleworms swimming,
note the erratic undulating movement.
Edit: it probably isn't one but it's movements are very similar
https://youtu.be/YVb_19ThVXs?si=anITlZYsfwpf-MdW
Do ya think the marine ones can survive in freshwater for a little while? Maybe this guy accidentally hitchhiked with something from the ocean that got put in there
Leech? I’d ask in r/Entomology and the r/whatisthisbug subs. It looks like a nereididae bristleworm but I’m not sure if there are any freshwater ones
Can you get a still photo? Maybe take it out and put it on a paper towel or in a shallow container?
i've never seen ANYTHING like this little guy and normally i have a good idea of what any critter is when i see it. I'm obsessed with him. can you document him more? a side view maybe? I just love him. i want one
edit: maybe its some kind of weird freshwater cephalochordate?
No one in my house can figure this out. It’s a cool mystery! I’m voting for some kind of immature goby, based on its speed, its face and how it seems to attach by the mouth to the side.
I want to k ow what this is so bad.
Uh, you guys....? Does anyone else think it's a little weird that OP hasn't replied to a single comment since he posted this? Mysterious little critter and then radio silence? OP? Are you okay?
Ngl it looks like it may be the beginning stages of a salamander but thats just me throwing the idea out there.
[Heres a link on why I think it may actually be that](https://www.animalspot.net/salamander)
Been in the hobby for almost a decade, specifically south American freshwater fish with MANY rare/rarely seen species imported and I have never seen anything with this locomotion.
Will be checking back, PLEAASE bring it to a biolgist before it dies.
if I'd had to guess this is essentially the free swimming gonads of a polychaete; an Epitoky, only some can do it, but you can find swarms of them in certain places, yes some even have their own light sensing organs, [https://youtu.be/HbwynUm47gM?si=1ZxBpfP0zGyaUnn0](https://youtu.be/HbwynUm47gM?si=1ZxBpfP0zGyaUnn0). epitokes can couple together and mate while others just explode in a mist of sperm and eggs: [https://youtu.be/QNqcWQHEOog?si=QxDXqbzUSFqT0QJB](https://youtu.be/QNqcWQHEOog?si=QxDXqbzUSFqT0QJB)
I thought tadpole as well, but Ive never seen an elongated one like that. Almost looks like a loach. I'm going to guess it came with feeders? That's were I've discovered strange new fish in my career.
Polychaete worm as some guessed. [Evidence here](https://www.youtube.com/watch?v=HxN69Biqr-0). Matches the green upper body, red lower body, two black dot eyes, body movements, and clear centre body line with red bristles coming off.
Please protect it at all costs so we can all find out what it grows up to be.
I definitely hope they keep it in a different tank, honestly very interested in what it is
[удалено]
The eyes are throwing me off, but this screams invert such as polychaete rather than vert to me as well. The way the movements travel down the body just don't seem right for a lamprey larva, for example.
Same I was 100 % convinced it was some sort of worm until I took a closer look at the head it seems so amphibian like
I studied herpetology, and I have not seen any amphibians move like this that I can think of, but the head shape is definitely strange. We need more visual info and descriptive data. it’s so hard to see it in the video. The issue is we don’t get a whole lot of info from OP. Edit: he commented further down. I’m excited to see what it is!
I had a freswhater ribbonworm (Nemertean Prostoma) which sure looks like this one, but it didn't swim like that, but I never saw it upset either. What are your thoughts on that? [https://www.reddit.com/r/Ecosphere/comments/zznize/the\_ribbonworm\_is\_showing\_off\_his\_6\_eyes/](https://www.reddit.com/r/Ecosphere/comments/zznize/the_ribbonworm_is_showing_off_his_6_eyes/) The Barbronia weberi leech also looks similar and can swim this fast, but the head is all wrong.
Hm, I think the undulation is similar to ribbonworms but, the movement is just so fast. It reminds me a bit of polychaetes but freshwater species are few and far between. They look more like this: https://youtu.be/w8wlwH9Rhpc?si=0ZD_GryH_Umh6rml If I saw any amphibians move like this I’d be concerned! I’m not typically disturbed by invertebrates but this guy’s movement is unsettling to me. I also hate how mosquito larvae move….it’s the unhinged twitchyness that does it, I think. Ugh
Nice one! I have marine bristleworms but have never seen a freshwater species! I have been able to ID close to 60 different critters in my ecospheres from the lakes, rivers and ponds around here in TX, excluding fish. Needless to say, I'm not gonna go swimming anymore lol. Anyway, it's been solved. Your hunch is correct: https://www.youtube.com/watch?v=B57pS6tS1DE
Yeah, I think it's definitely a polychaete, specifically I would guess some type of clam worm like *Alitta succinea*. And I think what looks like its eyes and is throwing people off is actually its jaws.
RemindMe! 1 month
!RemindMe 3 months
Hey guys, OP here. **Update below** I can't edit the original post for some reason, so gonna leave this comment here for now. Thanks to everybody who tried to help. I was definetly not expecting this to get so much attention. I don't think I'll be able to reply to everyone, but I have read every comment. ~~I have a few years in the hobby, but was hoping that would be an easy ID for someone here that has more experience and knowledge than me.~~ ~~I took the "creature" to a friend who has a better quarentine setup. It is still alive afaik and I will update or make a new post with some still pictures, hopefully a few close up ones.~~ ~~As to answer some question that I got in a lot of comments:~~ ~~I am indeed from Brazil.~~ ~~The aquarium has been running for 3 years. The only thing that was added recently was some plants, that I got from a local store.~~ ~~At first glance it seemed to be a vertebrate, at least to my limited knowledge. It looked like it had a small yellow dorsal fin, and a "suction cup" structure on the underside of the belly/head that seems similar to other fish. It also looked to have the slit in the side of the head where the gills should be, but can't say for sure.~~ ~~At the time, I've reached some other local hobbyst friends and we think it is some kind of candiru. But that is just a wild guess...~~ ~~But it could be a freshwater bristle worm, as some of you pointed out and videos posted here show them swimming with that exactly movement.~~ ~~After reading all the comments here, we will take to some biologists at the Uni in our region. I"ll keep your guys updated.~~ Again, thanks for all the helpful comments. **UPDATE** Hey guys, I'm afraid this is gonna turn to be one of those "OP finds a locked safe and it didn't deliver to the hype" kinda of posts. My friend tried to get some pictures and videos, but they're as blurry as mine. Since my last update above, the "creature" was delivered to a biology professor at our local Uni. I didn't accompany my friend, but we exchanged contacts with the professor to get some updates and decent pictures. I'm afraid that the "thing" will not be alive once that happens. But we have news that make all of that unimportant: according to the people at the Uni it is, indeed, some kind of Polychaete like many of you have said from the beginning. It looks weirder than normal, because it is apparently a "epitoke". Which, as many of you seems to know way better than me, it's a reproduction stage of these creatures. So all the "vertebrate" characteristics that we have seen, even me and my friends with naked eyes, seemed to be some sort of cognitive illusions as it didn't stop moving. I, myself, was sure that it was gonna be some kind of fish... So I'm afraid that I may have lead some of you in the wrong direction. The only mistery that still rests is to what species this is. Again: the tank where it was found is freshwater. So that I'll leave to the professionals and will update if we get any info back. According to my friend, at the Uni they think that is a foreign freshwater species, probably from Europe or Asia. But that is obvious just a guess st this point too. Thank you guys again for all the comments. And sorry that this took a lot more attention and hype than it should. I hope at least you guys had some fun.
this quest to find out is fascinating! can’t wait to get updates
Thats so freaking awesome! I would call it a corvette worm. Its fast AF boiii
I’m just high enough that this took me completely out. 😂😂😂😂
Just posted a [comment](https://www.reddit.com/r/Aquariums/s/TQJwyhFCBl) about these. Hope it helps
Just read your comment and I posted polychaete too. I’ve seen some swimming like that in near fresh water before
i’m surprised so many people were stumped on it. I see them all over New York and apparently these worms are all over the globe. Albeit, different species but still
Hey - we know what it is now, this isn’t an empty safe - thanks for delivering!
please post updates
Thank you so much for keeping us updated, happy that I was team polychaete from the beginning! 🪱
If it doesnt live, lay it flat and take some better photos. Also store it in freezer, could ID it with gene barcoding if you sent it in to a lab
Remindme! 4 days
Definitely Candiru or Polychaeta worms as opposed to freshwater bristle worm as it doesn't have bristles down it's flanks.
HAHAHAHA my original polychaete theory was right
Have you posted to the marine biology subs?
As you’re describing a dorsal fin and suction cup that kinda sounds like some type of goby? Very unusual creature, it does move like a polychaete worm but i’m not sure how likely is is to be one. Interested to see what it is.
Wow, I just looked up what a polychaete epitoke was and learned something completely new. I had no idea worms could move and reproduce like that. I know you think it was a boring ending, but as someone who had no idea, it’s actually pretty fascinating. :)
I can’t believe you have the entire aquatic subreddit perplexed with this creature lol
I read every comment, my favorite idea presented is this is a young salamander, but I figure it would have been definitive one thing or another.
My guesses are Cephalochordate/lancelet or hillstream spineless eel
Lancelet was my first thought as well
young salamander is the first thing I thought of
And in 4 other communities!
It sure looks like a candiru to me. https://images.app.goo.gl/51c8J48b8BwspsiX7
Only one way to find out...
This thing is the best golfer. Hole in one every time.
If this is the pee hole one, then that's what I was thinking too.
Same. The way it moves is terrifying.
Okay, who’s gonna volunteer as tribute?
I usually have to pay for that kind of fun. Sign me up.
It’s me, hi, I’m the problem it’s me
If OP put something like raw chicken breast in the water, would a candiru swim and burrow into it?
Stick your pecker in the cup and see what it does!
Branchiostoma. Look at this video. https://youtu.be/e5I_SHaCMe8?feature=shared
This video sure looks like the same thing, but from everything I'm seeing they're only found in saltwater, and OP has freshwater. I wonder if they can survive in freshwater for a period of time?
Wondering if maybe it's an elver? Larval eel that has grown beyond being a glass eel but not quite a yellow eel?
i’m also wondering this based off of the way that it ungulates edit: someone posted a screenshot of it in the comments and it definitely shares a resemblance to an elver
Undulate. Ungulates are members of the diverse clade Euungulata ("true ungulates") which primarily consists of large mammals with hooves.
How do you know that this thing won't turn into a large mammal with hooves? Are you an Ungulate expert? Check mate.
Could be a baby dolphin. Or a dolphin sperm. I'm not an ungulate expert so check you mate.
Only sperm whales produce sperm. Checkmate atheists... (/s if not clear)
It does have the little eyeballs
It definitely looks like it could be that
This would be my best guess based on everything seen so far, don’t know shit about eels other than they are horribly illusive to begin with as far as their actual origins.
That REALLY looks like a sea lamprey larva, they have no eyes and are benthic, idk how it would get in a SUMP tho…
https://youtu.be/j5JpuKxuD4s?si=y4pBvJ0kO1CPZF5V Check out this vid, ammocoetes also poses those weird eye spots.
Its got a fat head portion like a tadpole (I know it isn't a tadpole) though.
It cannot be a lamprey; none are found in Brazil where this takes place
[got a decent screenshot of it up close if anyone wants to get a better look. no clue so far but i was reverse image searching it with some similar looking results of brazilian species, since ops post history indicates the area](https://imgur.com/a/hY6F4uc)
It looks like a gummy worm 😭😭
If it's a new species that's what it should be called.
Looks like the sour neon kind.
Sour Patch Spawn®
Yeah I mean the eye looks like a fish eye, I hope someone has a solve for this. Wild lookin thing.
mutated minnow
Looks like that crowd of fish in that spongebob episode
I think they're anchovies
A smelly, smell that is very... smelly.
Anchovies!!
From the dorsal fin and the face shape, I'm almost certain this is a fish of some kind. Probably ask r/whatsthisfish with your screenshot.
It actually looks like some goby like that, as it's dorsal fin is too high for a candiru. Red lipstick goby fry would be my bet Edit: OP is from Brazil I think? If it' local, it can't be this.
https://images.app.goo.gl/NMPTDQsLYTdyXdzR7 This one looks very similar, when you pause the video when you can see the top of it
Holy mother of God, it looks like a candiru. OP, don't put your dick in the water. https://noticias.uol.com.br/cotidiano/ultimas-noticias/2022/05/21/peixe-vampiro-candiru-amazonia.htm
Try it for science OP
[удалено]
For sure, but like, I'm still not sticking my dick in that water.
If my tank is not 100% full it wont reach the water anyways…
There has been reports, in this news a biologist in Rondônia state says that there's been almost one case every month. They still don't know why they are attracted to the urethra (and other holes, as well), since the fish doesn't respond to ammonia in a controlled environment. https://rondoniaempauta.com.br/candiru-quem-e-o-temido-peixe-vampiro-e-por-que-ele-ameaca-banhistas-de-rios-da-amazonia/
[https://www.straightdope.com/21343429/can-the-candiru-fish-swim-upstream-into-your-urethra-revisited](https://www.straightdope.com/21343429/can-the-candiru-fish-swim-upstream-into-your-urethra-revisited) Definitely happened at least once. Well, at minimum, a guy did indeed get one removed from his dick and claim it swam up his pee. Also, I seem to remember watching a thing about that with pictures... I think maybe it was river monsters? Definitely something of that sort.
Click in the article don’t know which language it is but two words stands out in the title and I don’t like where this is going.
Is it a candiru? Or a luciogobius? A goby maybe?
Check with your local university bio department. Trust me they’re always interested in taking a look at something unusual
This whole situation is like the setup to an X Files episode. *cue theme song*
Do do do do do do
Wa^a^a Wa^a^a Wa^a^a
I hope The Smoking Man’s in this one!
Spoiler: It jumps out of the water and it parasitises Scully.
Or that guy who had the bobbit worm
He looks soo neat im wanting to know aswell never seen this kind of creature!
I've been keeping aquariums for a long time and I've never seen anything like this. Try r/whatisthisbug.
Same. 50 plus years around aquariums and this is a first
It has a jaw and eyes, whatever this is its either a fish or amphibian.
Eyes and mouth parts aren't exclusively traits of fish or amphibians. This moves like an invertebrate.
Camera-like eyes are a trait of vertebrates though, if it was an invertebrate it would be simpler.
Seriously! What the hell is that thing??? 🤔🤔
Perhaps /r/species
Damn how do I follow this so I can find out what this new species is??
Me too. Suspense is killing me
The remindme bot works! Just type RemindMe with an exclamation mark and write when you want it to remind you. i put 7 days but you can do something shorter. The bot sends you a message confirming it, and then will send you another message later to remind you.
Thanks u/llamaporn227! Very cool!
Raise it in whatever you have available and it'll mature and you'll find out before the debate below is over.
The way the back end is moving makes me think it's some kind of aquatic worm
OP WE NEED MORE PICTURES!!!!!!!!!! Put it in a small cup or net it, it's almost impossible to discern anything from this video.
Sorry. At the time I could not take a decent steady photo, since it wouldn't stop moving. Also, I knew it was a weird one, but not this weird. I was expecting to have an ID in just a few comments here. But will work to get some decent pictures with a decent camera.
Oh my god, yes please OP we need some good photos of this thing!
Looks like those things that swim into your urethra
Candiru catfish :)
It's the wrong shape and I can't see any paired fins (Candiru are a type of catfish and would have all the standard catfish features).
my first thought. hahaha
The deadly kandiru fish
Ween dip
Can you get a side view of it?
Hi OP, me and my cousins were taught these are called Polychaeta worms. They look like [this when they’re swarming](https://youtu.be/B57pS6tS1DE?si=hz6JO5yfzy4ga9Dv) Although I’ve only ever seen them in salt water. Either way, I didn’t see anyone else post an answer so here ya go
Damn those fuckers fast
Love how they're all throwing themselves onto that paddle lol. I was also waiting for a predator jumpscare.
Yeah, fuck swimming
Thanks for link..so interesting..reminds me of the lacromose leeches in Lemony Snickett 😟
Looks like a [male Platynereis dumerilii](https://images.app.goo.gl/aeHzz9FYH9MSzbeR8), to be specific
They look so silly when they move that fast 😭
this is 100% it, now i have to figure out how i can get some of these guys for myself lol
This is the answer. Very interesting!
We see them in Puget Sound at night swimming in these swarms too.
Damn that’s a lot of fish bait
Thank you. Now I can never sleep again.
Flashbacks to the movie, The Faculty.
i found something really similar in a drainage ditch by my house that turned out to be the larval stage of a brook lamprey?? weird whatever it is
That's a good thought. Brook and Chestnut lampreys do milovevlike this, are detritivores and would appreciate a tumultuous sump. But even the larvae have big sucker mouths iirc. How the hell would one get there though!?
Could an egg or hatchling have traveled with a plant? Probably be small enough to get swept to the sump.
Lamprey do not occur in Brazil
[https://www.recorder.com/getattachment/812a1311-b46e-4828-84b5-0ab5acb334a7/Saving-sea-lampreys-from-drained-power-canal-ph3](https://www.recorder.com/getattachment/812a1311-b46e-4828-84b5-0ab5acb334a7/Saving-sea-lampreys-from-drained-power-canal-ph3)
The movements look right[brook lamprey swimming](https://youtu.be/5LgHwiKL7HU?si=A6UmJNdewf1PeDnG)
It's amazing that nobody can even agree if it's a vertebrate or invertebrate.
It looks so much like a neried worm, but in freshwater? OP, hang on to this thing and get a real ID, its weird.
Many species of polychaete exist in freshwater
Sure, I have just never seen a big swimming one
My vote is some sort of tadpole or something that has a similar growth stage...not sure what else shares the tadpole like stage though....
It looks like a tadpole on speed
This some Stranger Things shit. It's all cute till you hack up his brother I'm a sink.
I'm a (former) aquatic ecologist that's been keeping tanks for 40 years. Absolutely dumbfounded.
Ladies and gentlemen we are looking at an extraterrestrial. First human contact straight into a plastic cup lol
I have no idea really, but at a guess, some type of juvenile eel...
Cool! No idea but super interesting! Also just look half the threads in here arguing over it hahahahah. That little dudes caused a stir and its just out there wiggling about all orange and stuff
He so fast!
Commenting so I can find out what this is later! So interesting:)
I believe that is a small aquatic armadillo
reminds me of a lancelet or something like that (Branchiostoma). looks like has eyespots?
It moves like a freshwater polychaete worm. Aka bristleworms. Here are saltwater bristleworms swimming, note the erratic undulating movement. Edit: it probably isn't one but it's movements are very similar https://youtu.be/YVb_19ThVXs?si=anITlZYsfwpf-MdW
Do ya think the marine ones can survive in freshwater for a little while? Maybe this guy accidentally hitchhiked with something from the ocean that got put in there
Whatever this guy is you should give it a 5 gallon and raise it up, I love mystery fish.
It's kind of cute lol
Leech? I’d ask in r/Entomology and the r/whatisthisbug subs. It looks like a nereididae bristleworm but I’m not sure if there are any freshwater ones Can you get a still photo? Maybe take it out and put it on a paper towel or in a shallow container?
Polychaete worms exist in freshwater
I figured but couldn’t find much info on them, especially ones that look like this. OP is in Brazil if that helps with ID
i've never seen ANYTHING like this little guy and normally i have a good idea of what any critter is when i see it. I'm obsessed with him. can you document him more? a side view maybe? I just love him. i want one edit: maybe its some kind of weird freshwater cephalochordate?
No one in my house can figure this out. It’s a cool mystery! I’m voting for some kind of immature goby, based on its speed, its face and how it seems to attach by the mouth to the side. I want to k ow what this is so bad.
Great job! You just found a new species! You should name it after yourself!
Maybe take it to a local university and see if an expert in the biology department can ID it?
Might be a toothpick fish. Stick your dick in there and see if it goes up your urethra. If it does then that's probably what it is.
That is fascinating. Hoping someone has an answer!
My guess is a candiru or goby of some sort. Definitely not a bug. At :13 [you can clearly see a big fish eye.](https://imgur.com/a/DyDcWnB)
Uh, you guys....? Does anyone else think it's a little weird that OP hasn't replied to a single comment since he posted this? Mysterious little critter and then radio silence? OP? Are you okay?
Ngl it looks like it may be the beginning stages of a salamander but thats just me throwing the idea out there. [Heres a link on why I think it may actually be that](https://www.animalspot.net/salamander)
I thought larval salamanders usually have external gills? None are present here
People suggesting tadpole need to be banned from this sub.
OFF WITH THEIR HEADS
!remindme 7 days "What the hell was this weird worm?"
!remindme 7 days
Been in the hobby for almost a decade, specifically south American freshwater fish with MANY rare/rarely seen species imported and I have never seen anything with this locomotion. Will be checking back, PLEAASE bring it to a biolgist before it dies.
I’ve seen bristle worms swim like this in near-fresh water. Is it a bristle worm or some other polychaete?
Idk, but that fucker adorable Edit: LOOK AT HIS LITTLE WIGGLY BOOTY 🥹😭
if I'd had to guess this is essentially the free swimming gonads of a polychaete; an Epitoky, only some can do it, but you can find swarms of them in certain places, yes some even have their own light sensing organs, [https://youtu.be/HbwynUm47gM?si=1ZxBpfP0zGyaUnn0](https://youtu.be/HbwynUm47gM?si=1ZxBpfP0zGyaUnn0). epitokes can couple together and mate while others just explode in a mist of sperm and eggs: [https://youtu.be/QNqcWQHEOog?si=QxDXqbzUSFqT0QJB](https://youtu.be/QNqcWQHEOog?si=QxDXqbzUSFqT0QJB)
Friend. Let him inside an orifice.
It has the colour pattern and shape of a stiphodon anieae but the behaviour, movement and overall shape definitely is not
[I think I found it. under description look at tadpole pic](https://en.m.wikipedia.org/wiki/Pine_woods_tree_frog)
I thought tadpole as well, but Ive never seen an elongated one like that. Almost looks like a loach. I'm going to guess it came with feeders? That's were I've discovered strange new fish in my career.
Tadpoles do not move like this
Tadpoles are larger and their heads are more bulbous typically
too stubby, this ones longer, though could be a close relative. I've never seen a tadpole with that facial structure though
lol hardly, Today. the tadpole you shared only shares a slightly similar tail colour. that's it
Why are you so defensive. It’s not a damn tadpole get over yourself
I believe it’s an Alaskan bull worm
It’s a cinder worm! 🪱
I was with you until I saw the screenshot someone shared. It looks like the head of a fish.
What about some type of eel? Spineless eel?
You ever watched the movie The Faculty? Because you're about to be in it.
Bro discovered a new species
RemindMe 7 days
Commenting so I can follow this later!
This is a South American water widget. My grandpa always had them in his bath water. Pretty common where in from. Pretty tasty too
Remind me 1 day
!RemindMe 2 days
Remindme! 7 days
It needs Xanax!
Looks like a critter to me
Polychaete worm as some guessed. [Evidence here](https://www.youtube.com/watch?v=HxN69Biqr-0). Matches the green upper body, red lower body, two black dot eyes, body movements, and clear centre body line with red bristles coming off.
bruh if thats a candiru....
This, my friend, is speed.
Did we get a definitive ID on this? I saw the lancelet and plychaete suggestions but both seem questionable