Fish aggression, one fish targeting and nipping at the others

[Neleono]

Hi, sorry if this post is quite franticly made.
I just recently got some new fish and the one fish that was already in the tank prior to the restock is now bullying the other fish of his same kind. They are only a few days old and they seemed to be getting along before but over yesterday and today, the original fish has been really aggressive with the others, nipping at them, chasing them for minutes on end, and pushing up against them One of the fish whom he has been targeting the most is starting to slow down, he is breathing rapidly and is being constantly chased. He has also started to lay slightly sideways. Any recommendations on how to deal with this are welcome. Thanks for the help. Info below!

Tank size:29 gal
tank age: about a year
pH: 7
ammonia: 0
nitrite: 0
nitrate: 5
Temp: 75-76

Recent additions to your tank (living or decoration): 4 tetras and 3 of the platys

Exposure to chemicals: None

Edit: Also I feel its important to mention that the fish that is being bullied the most is the one from this thread (https://www.fishforums.net/threads/new-fish-swimming-sideways.468686/#post-4014906)

 

[mark4785]

What is your aquarium decor like? Do you have any hiding spots for the fish that is being chased?

 

[Neleono]

I have a good amount yeah, there's a big coral structure in the middle with lots of holes and some large plastic plants for them to hide in, but the bully fish just follows him in there.

I should also say that they are all males. Not sure if that is helpful.

 

[Colin_T]

what sort of fish are they?

video of the fish?

 

[mrsjoannh13]

Do you have a hospital or quarantine tank you can move either the bully into or the bullied fish? Otherwise, try to rearrange your decor so it seems like a "new" tank.

 

[Neleono]

There are 4 platys (2 painted, one micky, one sunburst) and 4 neon tetras. The two fish that are fighting are the painted platys, I will try to send a vid. In regards to a hospital tank, I have a 2 gal fish bowl I could use with a bubbler, (I don't use it as a real fish tank don't worry) but I'm pretty sure that's too small. Other than that I do have a 10 gallon planted tank with a betta in it but I'm not sure if they would get along, or if it could handle another fish because it is brand new (Not counting the cycle time).

 

[mrsjoannh13]

I'm wondering if you took just the one platy out and put in the 2 gallon for a while to see if that takes some starch out of his sails? Not permanently, but just isolate him for a bit and let the others establish their own pecking order in the larger tank then try adding him back in after a while. Or you could try to swap him out from wherever you bought him perhaps? I have one really aggressive tetra in my tank and if he doesn't repent soon and change his evil ways I might swap him out soon. He's a complete bully and stressing out the other tetras in his tank. Luckily he doesn't single any particular one out. He's an equal opportunity attacker. Anyone comes near his prime space in the tank and he dive bombs them like a shark. It's so frustrating.

 

[AdoraBelle Dearheart]

Hi, I should have read this thread first, just wrote a long reply about the chasing/bullying in your other older thread here:

New fish swimming sideways

Good afternoon, Yesterday I got some fish to add to my 29 gallon tank. I originally had one platy and I added 3 more, and 4 neon tetras. The fish in question was fine this morning but just recently started to swim sideways. He doesn't have any difficulty going to the bottom or top of the...

www.fishforums.net

But with this update, I'm even more suspicious that something might be wrong with the one being bullied. So the dominant one is trying to chase him out of the territory... sick fish attract predators, it's natural for the healthy fish to want to drive away a sickly one so it doesn't bring predators to them, but in an aquarium, there's no where for him to go. It sounds like he's becoming exhausted and weak, and needs to be got out of there.


The two gallon isn't ideal, but the betta tank might be even worse, hard to say since it depends on the personality of the betta - and whether the weak fish is actually ill. We don't want to potentially spread disease to your other tanks.

I would try either putting the weaker, bullied fish in the two gallon, with the air bubbler, some live plant to hide in (if it's empty, open and exposed, he'll feel vulnerable and even more stressed, and stress kills fish) or I'd get a breeder net or box and keep him in that in the current tank. Solves the water quality problem and means the other fish can't attack him, but not ideal either.

I'd get the bullied guy out and monitor in case he's sick. Re-arrange the decor in the current tank to make it look like new territories, and keep an eye on the bully. If he just switches to a new target, then you might have a problem fish on your hands.

 

[Neleono]

Ok, I just say your reply on the last forum and ill be sure to use both to make the plan of action. Thanks again!

 

[AdoraBelle Dearheart]

I'm wondering if you took just the one platy out and put in the 2 gallon for a while to see if that takes some starch out of his sails? Not permanently, but just isolate him for a bit and let the others establish their own pecking order in the larger tank then try adding him back in after a while. Or you could try to swap him out from wherever you bought him perhaps? I have one really aggressive tetra in my tank and if he doesn't repent soon and change his evil ways I might swap him out soon. He's a complete bully and stressing out the other tetras in his tank. Luckily he doesn't single any particular one out. He's an equal opportunity attacker. Anyone comes near his prime space in the tank and he dive bombs them like a shark. It's so frustrating.

Hey, just curious, what kind of tetra is it that you're having issues with? Just curious whether it's a neon. @NCaquatics had some nightmare neons at one point that were nipping everything in the tank, and I had an experience where my male guppies in a community tank had their tails shredded, and I suspected the neons. But they have a rep as the perfect peaceful community fish, so interested in what others have experienced!