Mysterious fry showed up in brand new tank

[jayman7713]

I am setting up a brand new 3.5 gallon planted tank for a Betta. I started cycling the tank last Tuesday and purchased three plants from the pet store (Hornwart, Amazon Sword, and Water Sprite.) On Sunday, I spotted a tiny fry swimming towards the top of the tank, and I have found a total of 6 since then. I hadn’t put any fish in the tank at this point, so I am assuming they hitched a ride on one of the plants. I think they hatched from eggs based on the fact that I didn’t notice any until Sunday. Since then I bought some First Bites for them to eat, and I have been doing daily water changes while the tank cycles.

 

Does anyone know what kind of fish these could be? They’re extremely tiny now and difficult to get a clear photo of. I am attaching a photo of one, as well as photos of the 3 tanks that my plants came out of at the store to help narrow down what kind of fish they could be.

[Zenzo]

Cool. Maybe swordtails since you just got the plants two days ago and the fry are already that big. 

[Odd Duck]

Very good guess from @Zenzo, but could potentially be white cloud fry, too, since it’s hard to tell exactly how big that fry is from a photo. If the fry are about 1/2” long, they are almost certainly swordtail fry that hitched a ride (by far most likely).  If they are 1/4” long or smaller, then white clouds that likely hitched in as eggs is more likely since swordtail fry pop out at nearly 1/2” long.

Did you buy the plants on Tuesday when you started cycling (a week ago, now)?

As the fry grow, it will become more obvious which they are, or if they are something else entirely.  Many species of fry just don’t show enough characteristics to definitively tell the species until they’re at least a few weeks old.  Sometimes they can’t be narrowed down until much older - some species of tetras (couple possible but unlikely candidates in the 2nd and 3rd tanks), for instance.  Or between species of rainbowfish.  It shouldn’t take much longer before we can see fins well enough to know if rainbowfish (top tank, least likely) are even possible.

[jayman7713]

On 8/23/2022 at 1:55 PM, Odd Duck said:

Very good guess from @Zenzo, but could potentially be white cloud fry, too, since it’s hard to tell exactly how big that fry is from a photo. If the fry are about 1/2” long, they are almost certainly swordtail fry that hitched a ride (by far most likely).  If they are 1/4” long or smaller, then white clouds that likely hitched in as eggs is more likely since swordtail fry pop out at nearly 1/2” long.

Did you buy the plants on Tuesday when you started cycling (a week ago, now)?

As the fry grow, it will become more obvious which they are, or if they are something else entirely.  Many species of fry just don’t show enough characteristics to definitively tell the species until they’re at least a few weeks old.  Sometimes they can’t be narrowed down until much older - some species of tetras (couple possible but unlikely candidates in the 2nd and 3rd tanks), for instance.  Or between species of rainbowfish.  It shouldn’t take much longer before we can see fins well enough to know if rainbowfish (top tank, least likely) are even possible.

They are very tiny. I would guess a little shorter than 1/4” long. I think it’s likely that they hatched from eggs due to the nature of how I discovered them. Over the span of 24 hours I noticed more and more in the tank, as if they were hatching that day. 
 

I bought the plants on Tuesday (8/16) and I noticed the first fry the following Sunday. Also it may be worth noting that I dosed the tank with ammonia that Tuesday to start the cycle.
 

Thank you for your response. I hope I can identify them soon, as I don’t know what to do with them at the moment. I have an old 10 gallon tank that I could set up for them, but if they turn out to be a fish that won’t thrive in a 10 gallon I’ll have to figure something else out. 

[Odd Duck]

If they’re tetras, they should be fine in a 10.  If they’re rainbowfish, they should at least have a 20 long as they grow.  All rainbowfish have double dorsal fins - tetras will have only a tiny adipose fin behind their dorsal fin where as rainbows have a prominent second dorsal that is usually more notable than their front dorsal fin.  You may be able to tell IRL much sooner than we can see in photos if they’re rainbows or tetras. Then it will just be a matter of figuring out what species of tetra.  Or if they’re white clouds (which are really the most likely to have bred in the store).

[Scot]

Those fish are absolutely tiny, I would stop doing water changes and let the tank do it's thing. Changing the water is probably swinging some water conditions you aren't aware of. Change the water because or when it's needed, not just cuz.

 

[jayman7713]

On 8/23/2022 at 2:42 PM, Odd Duck said:

If they’re tetras, they should be fine in a 10.  If they’re rainbowfish, they should at least have a 20 long as they grow.  All rainbowfish have double dorsal fins - tetras will have only a tiny adipose fin behind their dorsal fin where as rainbows have a prominent second dorsal that is usually more notable than their front dorsal fin.  You may be able to tell IRL much sooner than we can see in photos if they’re rainbows or tetras. Then it will just be a matter of figuring out what species of tetra.  Or if they’re white clouds (which are really the most likely to have bred in the store).

I will keep an eye out. Thank you so much for the help!

[FLFishChik]

On 8/23/2022 at 12:29 PM, jayman7713 said:

I am setting up a brand new 3.5 gallon planted tank for a Betta. I started cycling the tank last Tuesday and purchased three plants from the pet store (Hornwart, Amazon Sword, and Water Sprite.) On Sunday, I spotted a tiny fry swimming towards the top of the tank, and I have found a total of 6 since then. I hadn’t put any fish in the tank at this point, so I am assuming they hitched a ride on one of the plants. I think they hatched from eggs based on the fact that I didn’t notice any until Sunday. Since then I bought some First Bites for them to eat, and I have been doing daily water changes while the tank cycles.

 

Does anyone know what kind of fish these could be? They’re extremely tiny now and difficult to get a clear photo of. I am attaching a photo of one, as well as photos of the 3 tanks that my plants came out of at the store to help narrow down what kind of fish they could be.

Congratulations on your surprise babies! I never get that lucky! It’ll be fun to follow this to see what they turn out to be!!

[Cinnebuns]

Congrats on the free fry! I got plants today completely covered in ramshorn and bladder snails. Maybe someday I'll get something more cool like this haha. 

[Flumpweesel]

I wonder if this is an cunning plan by the fish shops to sift extra tanks.

I'm jealous I'd love a fry surprise. Probably end up in crazy where to keep them panic to