Black neon fail.

[Krakens_tanks]

Ok so this is going to be a longer sorta post so I apologise

Tldr: mature black neons are species aggressive and no one seems to say that before hand and we'll lesson learned.

So last Friday I finally picked up my 30 black neon tetras super excited and couldn't wait to watch them school for days to come.

For some info incase you haven't seen my multiple post about this tank. It's a 40B planted with Christmas moss, java ferns, brazilian pennywort, crypt wednii, foxtail fern, and a plant I just can't remember the name for the life of me ( very common plant though) two larger pieces of wood. temp is set at 76°, I dose easy green ferts and use co-op root tabs, water perimeters we're all 0 with the exception of nitrates at 10 - 20 ppm, oh was at 7.6, had been fully cycled for about 3 weeks as plants were showing new growth and even pearling. 

So went to the lfs that ordered the fish for me, I felt amazing as a large majority of the fish were really good size close to 1.5" maybe close to 2" in size i would say maybe 10 were smaller then that. From what I assume sexing them I had about 8 large females the rest were males. ( I think this was mistake number 1) 

Took the fish home left them to drip acclimate for around 30 to 35 mins. Everyone was looking good and healthy so I transferred fish into tank. Instantly fell in love and was swooning over my happy little tank ( insert ominous music here please )

Next morning I woke up and had 3 smaller ones that had passed I didn't think nothing of it cuz 30 fish in a bag for large period of time while shipping then being added to my tank losses were expected. Went about my day as normal came home from shopping with the wife had 2 more  smalls dead, again didn't shock me smaller fish being less hardy but I still wanted to check my water as I did just add 30 fish at once. Still everything was fine after testing so I fed the tank and turned lights off for the day. This is where things started getting a bit odd. I noticed the school had now become 2 separate schools one with all the females and majority of the larger males the second the remaining small males and a few of the larger males. The larger school kept swimming in and out of the foxtail darting at any fish from the second school I assumed maybe those large females are full of eggs and they were trying to pair up or show off even though my tank doesn't really have any kind of swan mop but maybe the foxtail they were claiming was there best option so they got territorial over it. Figured they would realize it wasn't going to work or hell maybe lay eggs but that was as far as I though it would go.... Till the next morning...

10 fish were dead and had there fins ripped off laying dead at the bottom of the tank with marks all along there bodies. (Mind you they are the only fish in the tank no others) so I immediately flipped out and thought my water crashed as I was under the belief they were peaceful fish and maybe just picked at them once they died. Tested water which as far as my api master test kit said was perfectly fine yet again I assumed human error and tested 3 more times to be safe... Still nothing so I did a massive 65% water change cuz I was convinced I was doing something wrong while my wife took a water sample to 3 lfs to get tested all three stores agreed water was in good condition for fish. So I was at a complete loss. I assumed maybe a bad batch from the fish farms as it's known to happen or maybe even neon tetra disease then my phone rang my lfs called to let me know fish for my wife's tank had come in. So we went picked those up (I also picked up some fish for my tank which I know most people will say that's a terrible idea as I'm currently loosing fish left and right) came back added 6 albino Corey's and 4 scissor rasbora ( acclimated the same way as mentioned above ) We made dinner ate watched a movie went back to the tank another 4 dead. I am in full on I give up mode I had no clue what else to do. 

So last night I decided to stay up and watch the tank, lights off only light was in the back of the room which gave me just enough to see into the tank where I would periodically look to see what the fish were doing. Then it happened to disbelief I saw 4 of the large neons group up and nip the fins right off of another neon. I quickly tried to grab the fish to move to a separate tank to see if It would be ok not even 5 mins later that neon passed. So I go back to watching by 530 am they had taken the pack down to 7 neons 4 males 3 females are all that's left. 7/30 survived. I was truly miffed as I was led to believe they are peaceful fish everything online that I read, people I had talked to everything, then I started searching other forums and pages specifically for black neon aggression in the search bar come across like 4 or 5 others who have had this same problem. Seems once they reach a larger mature size they become territorial and aggressive to there own species.... 

Ultimately this is a learning experience that I should dive a lot deeper into researching fish just because majority says peaceful doesn't mean they are always going to be that way...

Side note this entire process I was speaking with @xXInkedPhoenixX who also purchased black neons around the same time and has seen some aggression as well. Luckily no where near my level but still aggression all the same.

Now I'm sure there will be a large number who will try to call BS and I don't blame you I wouldn't believe this if it didn't happen to me personally but thought it was worth sharing with others.

[BBQRacer]

😶 um good luck.  This is out of my league.

[Krakens_tanks]

Just now, BBQRacer said:

😶 um good luck.  This is out of my league.

Your good this was basically just like a journal entry for my own short comings. 

[Will Billy]

Interesting. I had a school of black neons, and over a short period of time they died one by one. To this day I still have the one last black neon, and he has been fine ever since. Might be a coincidence i dunno. My regular neons have had no problem. I jokingly call my one and only black neon the black sheep of the family. 

[lefty o]

ive had them before, not currently and never saw this behavior from them. i tend to think a lot of species are like this, generally peaceful, but have the occasional bully in the bunch. it certainly sucks when it happens.

Edited April 12, 2021 by lefty o

[Maggie]

Interesting  - I was at a chain pet store and saw a whole tank of serpae tetras nipping each other's fins. Pretty much all of them had serious fin damage. It was a very sad sight. 

[Hobbit]

Weird, and good to know. Is it possible there’s a fish that looks really similar to a black neon tetra but behaves very differently?

[Krakens_tanks]

43 minutes ago, Hobbit said:

Weird, and good to know. Is it possible there’s a fish that looks really similar to a black neon tetra but behaves very differently?

I don't think there is anything that looks exactly like a neon tetra... Not to memory anyway but I guess nothing is impossible now a days.

[Cory]

Are you sure they were black neons and not like emperor tetras or something? I’ve never seen what you describe.

[xXInkedPhoenixX]

...and yes as @Krakens_tanks mentioned, because he'd brought them up in a thread, I got really interested in them. I'm not one to just go out and buy a fish so I did my reasearch too, and I concur- nobody mentioned potential aggression. 

I have a 20 gallon high- all water parameters are perfect. The first day I got 6, found 1 small one dead within a day, didn't look sick but I didn't see any signs of fin nipping at the time- in fact it looked perfect. I thought since they were acting so darty (but in a nervous way, not an aggro way, I witnessed no fighting) maybe I just didn't get them in a large enough number- so I went back to the LFS and bought 8 more. That would give me a baker's dozen. I now have 11. The 1 small one that I have since found had no fins, but otherwise intact- and they've buried the body on the 13th, no idea still where that one is. I have 2 large ones left I assume are females? and the rest are small which are the size of the dead ones I've found. I expect the serial killers to strike again.

Cherry shrimp are doing great tho. 

Edited April 13, 2021 by xXInkedPhoenixX
1 more thing.

[xXInkedPhoenixX]

Oh and I should mention @Cory, @Krakens_tanksand I live in different states- our fish look exactly the same, both our LFS sold them as Black Neon Tetras

[Krakens_tanks]

2 minutes ago, Cory said:

Are you sure they were black neons and not like emperor tetras or something? I’ve never seen what you describe.

I ordered black neons and these are what was sold to me. If they are not black neons I would feel like a fool but also it would make a good argument on a refund for all those fish since they were not that cheap to have so few left.

First picture was them at store where they sat for about 20 mins till I picked them up second was my tank

[xXInkedPhoenixX]

@Krakens_tanks yours look like mine my friend.

[Krakens_tanks]

1 minute ago, xXInkedPhoenixX said:

@Krakens_tanks yours look like mine my friend.

Yea they definitely don't look like emperor from what google shows. Like I know people will think I'm crazy cuz like I posted if I wouldn't have seen it with my own eyes I wouldn't believe it either. I'm starting to belive that maybe I just got some crazy inbred psychos or someone cross breed something into them  that made them act weird

[Cory]

Hmm it's odd. Had them in tanks before, Had them at the store in the hundreds, thousands really over the years. I've never seen nipped fins with them.

[Krakens_tanks]

Just now, Cory said:

Hmm it's odd. Had them in tanks before, Had them at the store in the hundreds, thousands really over the years. I've never seen nipped fins with them.

Yea I wish I would of taken pictures but the thought never hit my mind I was just sorta stunned and saddened at the entire situation. 

[JettsPapa]

I was surprised to see this also.  I have some in my 65 gallon tank and have never seen any issues with them.  I had about a dozen for a year or so, and then got 5 a couple months ago from someone who needed to rehome them.  The 5 new ones were considerably smaller than my originals, but they fit right in with no issues.

[BBQRacer]

Could they be zombie fish?

[Hobbit]

@Colu might know if they’re true black neons or if they’re some other species. I’ve been trying to look things up and I found these similar options:

Hyphessobrycon lucenorum
Hyphessobrycon chiribiquete

Both were recently discovered though so I doubt they’d be bred anywhere, but maybe yours were wild caught...? It doesn’t seem likely but this is a weird situation.

They looked great in your tank too. 😥

[Colu]

 

28 minutes ago, Hobbit said:

@Colu might know if they’re true black neons or if they’re some other species. I’ve been trying to look things up and I found these similar options:

Hyphessobrycon lucenorum
Hyphessobrycon chiribiquete

Both were recently discovered though so I doubt they’d be bred anywhere, but maybe yours were wild caught...? It doesn’t seem likely but this is a weird situation.

They looked great in your tank too. 😥

They look like true black neon tetra hypressobrycon herbertaxelrodi to me

[Krakens_tanks]

2 hours ago, Hobbit said:

@Colu might know if they’re true black neons or if they’re some other species. I’ve been trying to look things up and I found these similar options:

Hyphessobrycon lucenorum
Hyphessobrycon chiribiquete

Both were recently discovered though so I doubt they’d be bred anywhere, but maybe yours were wild caught...? It doesn’t seem likely but this is a weird situation.

They looked great in your tank too. 😥

Tell me about it. My jaw was dropped by how good they all looked. Like I felt so proud of my first community tank in like 6 years then bam smack to the face.

[Hobbit]

@Krakens_tanks well it’s clearly not your fault and really unusual. It might be worth it to try again...? Maybe your LFS can try to get them from a different wholesaler?

[Fishdude]

I almost bought a group of these not long ago. I'm waiting until I move to redo a community tank, but this is interesting. I'll let you know if I get any and whether I see aggression.

[Kirsten]

Yikes! A terrible reminder that tetras are related to pirahnas, I suppose. The only thing I can think of is space, but if if a 40 isn't enough space for 30 tetras, I'll eat my hat.

I'm glad you stayed up and witnessed the crimes with your own eyes, though, because it would be terrible to blame yourself and get discouraged before even starting.

Maybe the tank was so lush and nice that they got all excited and territorial? Hope you're able to add some other fish and erase this bad experience.

[Krakens_tanks]

3 hours ago, Kirsten said:

Yikes! A terrible reminder that tetras are related to pirahnas, I suppose. The only thing I can think of is space, but if if a 40 isn't enough space for 30 tetras, I'll eat my hat.

I'm glad you stayed up and witnessed the crimes with your own eyes, though, because it would be terrible to blame yourself and get discouraged before even starting.

Maybe the tank was so lush and nice that they got all excited and territorial? Hope you're able to add some other fish and erase this bad experience.

So as it stands currently I this is the stock

2x b.neons ( they are definitely a pair 1M1F)

10 albino Corey's

6 scissor tail rasbora

6 rasbora het.

1 bamboo shrimp

Everyone else in the tank is doing amazing I'm assuming that last two are the dominant pair some how idk it's odd for sure. And I have seen tanks that are like 75G and have 85 neons so 30 in a 40 shouldn't have been an issue. Its just bad luck on my end but since adding the Cory's and rasbora I have cemented myself knowing my tank is fine as I have yet to loose a single one and they have been in there for 2 days now which I had already lost around half my neons by that point.