Random Fin Nipping With My Black Tetras?

FishForums.net Pet of the Month
🐶 POTM Poll is Open! 🦎 Click here to Vote! 🐰

Durbkat

Untrainable
Joined
Sep 3, 2005
Messages
4,128
Reaction score
0
Location
Kentucky
In my sig you will see how many black tetras I have in my long 20g and yesterday one of the smallest tetras had all of his fins no nipped fins at all then I look at him this after noon and a chunck has been taken out of his top fin. Also all the other tetras and spilt ragged fins from the nipping thats been going on. What is causing all this nipping and will it stop? If not what can I do to stop the violence?
 
Like I said in my first post I said look in my sig at the long 20g.
 
Are you seeing the nipping? I've never kept long finned varieties of anything, don't agree with it, but I'd have thought that a long finned and regular finned would recognise each other. What I'd guess is the normal finned group would express superiority over the long finned ones as they will be faster and more manouverable.

If all the fish are showing ragged fins, I'd be wondering about a bacterial infection, (fin rot). In pecking order disputes, usually only the most submissive fish get their fins nipped.

As always, trying to sort out something like this without seeing it and watching the fish is very difficult.
 
Yes I've seen it happen because I was looking at them and they were chasing each other and it looked like they were going a little faster than the fish being chased and they would nip them. But like I said before I went to bed and one of the new fish in their had all his fins he is also the smallest one. Then I woke up the next morning and a chunck of his top fin was missing like one of the bigger ones took a big chunck out of it.
 
Never mind I think it is fin rot because like two of the biggest long finned tetras fins were long and now their back fin only half left :crazy: What medicine should I use since I have the pleco. I have macracine 2 I believe and I think it cures fin rot is it true? If so would it be ok with the pleco and should I remove the filter media while treating so it doesn't absorb the medicine?
 
Maracyn one or two.

Maracyn
Manufacturer: Mardel
A broad-spectrum antibiotic for gram-positive bacterial infections. For infections of columnaris (body fungus), fin and tail rot, popeye, gill disease, and secondary infections.
Active ingredient: Erythromycin.
 
Maracyn 1 I believe on the package it just says mardel maracyn and it says it cures fin rot. So will this be ok to treat with the pleco in the tank since he doesn't have it? Also should I remove the filter media because I have done so before when I used it?
 
Black widow tetras -- if that's what you have -- are notorious fin-nippers. A surprising number of tetras are, including the very widely sold serpae tetra species complex, Hyphessobrycon spp. In some fish it's dietary (they're parasites effectively, taking chunks out of larger fish). In others it's a problem with behaviour. Because the school of fish kept in a tank is much smaller than it would be in the wild, where the school would have 100s of fish, the aggression isn't 'shared out' between fish and ends up causing physical damage.

Frankly, I've always thought it almost criminal that retailers sell schooling tetras in groups of less than 10. With only six individuals, you have far too few for the fish to form a balanced hierarchy, and the result is going to be nipping. They're also likely to attack other fish, particularly angels and guppies, which makes me suspect to some degree fin nipping in this species is a normal form of feeding behaviour.

Either way, fin rot and/or fungus are the by-product of fin damage. In well run aquaria, my experience is it's easy to cure and doesn't pose much of a threat. Of course if the fish are continually attacking one another, then curing the symptoms -- the fin rot -- isn't really going to fix the problem over the long term. If you want to have a mixed community tank in an aquarium as small as yours, you're probably best served by returning the tetras if you can, an opting for species that are easier to accomodate.

Cheers,

Neale

This is the FishBase preview pic of Gymnocorymbus ternetzi, just to check we're talking about the same fish.

tn_Gyter_f0.jpg
 
I agree well said.
 
Yeah thats the same fish I'm talking about. I also have the long finned version. I really think its fin rot because I used to have 3 of the regular black tetras in a 10g and their was no aggression in the tank they were just really shy. So this didn't really start till I upped the number of tetras. So my thinking is that the new tetras introduced the fin rot.
 
The new tetras are what introduced the aggression which made everyone more prone to finrot. besides smaller numbers meaning the tetras are bound to feel more nervous, when you added these new fish late, hierarchy had to be re-established. The smallest tetra you mentioned having been attacked first would also be the lowest ranking (due to size). Finrot doesn't usualy happen in healthy fish regardless of whether the new fish introduced it and, more often than none, the fish that catch finrot catch it as a secondary infection when they've been nipped or injured.
 
Spot on... couldn't have put it better myself.

The fin rot is a symptom, not the problem. Sometimes it's caused by problems in filtration, othertimes by physical damage. Either way, it doesn't "appear" in a tank without there being some trigger. In your tank, it's the black widow tetras.

A 10 gallon tank is really very, very small by aquarium standards. Experienced aquarists can manage some miracles (I've seen amazing 10 gallon reef tanks, for example) but otherwise these are best considered to be species tanks for something small but unusual (such as dwarf puffers, a breeding pair of dwarf cichlids, a colony of gobies). A 20 gallon is a much better place to start if you want a community tank with a mix of tetras, catfish, and so on.

A friend of mine set up a 20 gallon with about twenty diamond tetras (Moenkhausia pitteri), three small Corydoras catfish, and a couple of Otocinclus. She used plain gravel and a bunch of plastic plants, and put the tank near a window so light shone through the tank. It looked great, and was one of the best small tanks I'd ever seen. I'd recommend diamond tetras as being hardy, very pretty, and totally peaceful. With plenty of light, they really sparkle, showing off all sorts of colours. They're also very active, constantly chasing one another but never doing any harm or harassing the other fish.

Cheers,

Neale

The new tetras are what introduced the aggression which made everyone more prone to finrot. besides smaller numbers meaning the tetras are bound to feel more nervous, when you added these new fish late, hierarchy had to be re-established. The smallest tetra you mentioned having been attacked first would also be the lowest ranking (due to size). Finrot doesn't usualy happen in healthy fish regardless of whether the new fish introduced it and, more often than none, the fish that catch finrot catch it as a secondary infection when they've been nipped or injured.
 
So what your saying is that it most likley isn't fin rot but the hierarchy is being re-established thats why it seems like everyones fins are getting shorter? Is thier anything I can do to prevent infection like fin rot or something from building up on their fins? I know I can't use salt because of the pleco but is their anything else I can do?
 
No, it's almost certainly fin rot or fungus... what we're saying is that the fin rot isn't the problem per se, but a symptom.

Treating fin rot is easy. Go to the aquarium store, buy some fin rot remedy, and provided the damage isn't too far gone, the fish will be fine.

But treating the fin rot is skirting around the problem. At its most simple, the problem is this: in a small tank and in small numbers, black widow tetras tend to attack one another. There are two cures.
  1. Double the number of black widows, which may mean moving them to a larger tank.
  2. Return the black widows, and pass the problem on to someone else.
There really isn't anything much else you can do. If you choose to leave the fish in the tank as they are, and then add some other community fish, then the problem won't go away and could become worse. At best, the black widows will merely attack one another constantly, and you'll need to continunally add fin rot remedy. Things might settle for a while, but at some point one or other fish will decide to try and climb up the pecking order, and before you know it, the problem will be back. At worse, the black widows will vent some of this behaviour on the other fish, particularly slow moving things like livebearers, angels, Siamese fighters, gobies, and so on.

I'm sorry to make this all sound so gloomy. For what it's worth, you're not the first person to have been suckered into buying these fish. The list of fish that really aren't peaceful community fish despite being sold as such (unless you reallyknow what you're doing) is long: blue gouramis, yellow gouramis, serpae tetras, most Botias, convict cichlids, red-tailed black sharks, etc., etc...

Cheers,

Neale

So what your saying is that it most likley isn't fin rot but the hierarchy is being re-established thats why it seems like everyones fins are getting shorter? Is thier anything I can do to prevent infection like fin rot or something from building up on their fins? I know I can't use salt because of the pleco but is their anything else I can do?
 

Most reactions

trending

Staff online

Back
Top