White Patches On Tetra Fins?

[DeanoL83]

Hi,
 
I have just noticed that on my neon and serpae tetras that some of their fins (mainly their tails) have white patches developing on them rather than being transparent. Before anyone asks, they don't look like grains of salt so I don't think it's ich (but I'm not an expert).
 
Some of my neons have had their tails nipped and this is where the white patches are.  Is it a sign of infection? Or that it is healing?
 
Here are some pictures.  Very hard to get the neons and serpae to stay still long enough to take a good photo!
 
I'm hoping it's not some sort of fungus/infection like fin rot (which i've heard about but don't know much about).
 

 

[Byron]

From your information, I would assume this is fin nipping.  Nipped fins do have a whitish edge.  This is serious for reasons other than the fins themselves, and I'll come back to that.
 
Nipped fins can sometimes get fungus, but in my experience usually not if the fish are otherwise not stressed and in good health.  I certainly would not treat for this at this stage, as adding any substances will add stress to the fish, and when not essential this is only going to increase the problems.  However, I would certainly remove the cause, and this is the more serious issue here.  Once the nipping ceases, the fins should heal and grow back.  They will not regenerate if nipped down to the caudal peduncle (the body of the fish), but otherwise they should re-grow.
 
Fish being nipped are under stress, and this can initially be relatively mild, but as the stress increases it can take a very serious toll on the fish's health, significantly weakening the immune system, and this leads to other disease issues that the fish normally would fight off.  I would carefully observe things and find the culprits and remove them.  And here, I would first suspect the Serpae Tetra.
 
This species is a known fin nipper.  It must be kept in large groups which sometimes keeps this under control, or within the species itself, though not always.  Larger group means 10 or more.  However, before you run out and get more (assuming you have fewer than 10 now), this does not usually work when the existing fish have already started nipping; they usually continue.  Also, even with a larger group and if things returned to normal, there is the fact that some fish just encourage the Serpae to nip; which is why this species should never be housed with sedate fish (angelfish, any cichlids for that matter, gourami, etc).  The temptation is just too great.  I don`t know what else is in this tank, or what you have planned, but keep this in mind.  When all is said and done, removing the Serpae Tetra would be the wisest course of action here.
 
Last comment is that even if the physical nipping should abate, the neons having been subjected to this will remain stressed with the culprits in the tank.  Fish release pheromones (read by others in the same species) and allomones (read by other species) as chemical signals, and while we cannot see them, the fish can pick them up, and this adds stress.  It is like a child being bullied; the mere sight of the bully will frighten the child even if no contact occurs.  Quite a good parallel actually; we know what this does to a child over time, and fish are no different.
 
Byron.

 

[DeanoL83]

From your information, I would assume this is fin nipping.  Nipped fins do have a whitish edge.  This is serious for reasons other than the fins themselves, and I'll come back to that.
 
Nipped fins can sometimes get fungus, but in my experience usually not if the fish are otherwise not stressed and in good health.  I certainly would not treat for this at this stage, as adding any substances will add stress to the fish, and when not essential this is only going to increase the problems.  However, I would certainly remove the cause, and this is the more serious issue here.  Once the nipping ceases, the fins should heal and grow back.  They will not regenerate if nipped down to the caudal peduncle (the body of the fish), but otherwise they should re-grow.
 
Fish being nipped are under stress, and this can initially be relatively mild, but as the stress increases it can take a very serious toll on the fish's health, significantly weakening the immune system, and this leads to other disease issues that the fish normally would fight off.  I would carefully observe things and find the culprits and remove them.  And here, I would first suspect the Serpae Tetra.
 
This species is a known fin nipper.  It must be kept in large groups which sometimes keeps this under control, or within the species itself, though not always.  Larger group means 10 or more.  However, before you run out and get more (assuming you have fewer than 10 now), this does not usually work when the existing fish have already started nipping; they usually continue.  Also, even with a larger group and if things returned to normal, there is the fact that some fish just encourage the Serpae to nip; which is why this species should never be housed with sedate fish (angelfish, any cichlids for that matter, gourami, etc).  The temptation is just too great.  I don`t know what else is in this tank, or what you have planned, but keep this in mind.  When all is said and done, removing the Serpae Tetra would be the wisest course of action here.
 
Last comment is that even if the physical nipping should abate, the neons having been subjected to this will remain stressed with the culprits in the tank.  Fish release pheromones (read by others in the same species) and allomones (read by other species) as chemical signals, and while we cannot see them, the fish can pick them up, and this adds stress.  It is like a child being bullied; the mere sight of the bully will frighten the child even if no contact occurs.  Quite a good parallel actually; we know what this does to a child over time, and fish are no different.
 
Byron.

 
 
Thanks for the response Byron, you always give very detailed, informative answers Much appreciated, particularly the information about the caudal peduncle and the pheromones and allomones
 
When I first was buying fish for my tank, the guy at the LFS told me that Serpae's are hardier than the other tetras they had so they would be a better fish for a new tank.  He didn't mention anything to me about cycling at all, so unfortunately, they were my first fish and suffered through my fish-in cycling.  They have all survived!
 
About three days after buying the tank and fish, I found this site and really started to learn a lot.  So it was after purchasing the Serpae's I did research and found out they can be a fin-nipper. I have 5 of them.  
 
The thought of buying more to build a proper school did cross my mind but unfortunately in my ignorance I bought a lot of other fish and my tank is stocked so couldn't really get anymore.  The store is not willing to take back fish either, so I will have to look at getting another tank at some stage to maybe do some shuffling of fish.
 
 
Seeing that there are white marks on some of the serpae's fins too, does that mean that the serpae's are nipping at each other I assumed they would only nip at other species? 

 

[Byron]

Serpae Tetra will almost always nip one another; when kept in groups of 10 or more, this can sometimes be absent, but this is no guarantee, it is simply in the fish's nature to nip their fins.  I don't worry so much about this, as it is part of their specific "make-up," but when other species become targets, that is something that has to be addressed as the stress to the other fish is more serious.
 
Perhaps you can find another aquarist locally who will take them?
 
Byron.
 
P.S.  Thank you for the kind words, they are sincerely appreciated.  B.