Neon Terta Has A Blister On Mouth

[Kalderin]

yesterday i did a 25% water change on my 200ltr tank, this morning i notice one of my neon tetra has a blister like growth on its lower lip, he is acting aggressively towards the other neons in the tank and i am concerned that he may have an infection of some type. 
 
the tank is cleaned every 7 to 10 days.
PH is at 6.8
nitrate and nitrite are all in acceptable levels and 0 ammonia.
i keep the tank at a constant 27 degrees Celsius.
 
the fish i have in the tank are: 22 neon tetra, 2 sucking catfish and 12 guppies.
 
so far no other fish are showing any signs.
 
any suggestions?

 

[the_lock_man]

Hmm, we much prefer actual numbers on here, so I'm gonna ask you for the numbers for both nitrite and nitrate. If nitrite isn't 0ppm, then the suffocation being suffered by the fish as a result could have weakened it enough to cause a secondary infection. Nitrate should be no more than 20ppm above your tapwater level, and if that's up around kinda 100ppm or above, we are starting to get into the problematic area.
 
A photo of the blister would be great too.

 

[ncguppy830]

^+1
what color is it?
search cottomouth and see if that looks like your fish has

 

[Kalderin]

nitrite is 0,
nitrates are around 80, so i assume that is bad. i have put a dose of prime in to help lower the nitrate levels.
also i never realized how hard it is to get a photo of a neon tetra.
 
http/imageshack.us/photo/my-images/607/4vnd.jpg/
 
and,
 
http/imageshack.us/photo/my-images/443/jl1q.jpg/

 

[DoubleDutch]

Often seen with neons and cardinals. Still don't know exactly what causes it.
Always thought that it was Columnaris, but there are no reports that other fish in the tank were infected.
Lots of guys tried to treat it with several meds, but untill now no one succeeded to my believe. Could be cused bij an Iridovirus as well (that's my thought being not treatable) In that case it could be Lymphocystis, which can dissapear on it's own. In earlier cases the infected fish (nearly) always has been euthanised though (sorry).
27C is warm for neons by the way. Not the reason though !

 

[the_lock_man]

Prime won't lower nitrate. 80 is a bit on the high side, but not dangerously so, so I would say that you need to increase the amount of water you change, and try to be regular at doing it at weekly intervals, rather than 7-10 days. And as DoubleDutch says, lower the temp a bit.
 
Mind you, if DD can identify what it is from those piccies, he's bloomin marvellous! Gotta say, he does know his fish illnesses though, so he may well know what it is without the photos.

 

[DoubleDutch]

These white mouth ulcers are quite common with neons and cardinals. I'am angry still not knowing exactly what causes it though. Overhere we tried with heavy meds / antibiotics, but nothing seems to help arghhhhh. That's why I'm thinking of a virus. Also read lots of fish are transported from asia with Iridovirus.

 

[DoubleDutch]

http/www.aquaforum.nl/ubb/ubbthreads.php?ubb=showflat&Number=125189&page=1 For instance a thread on the Dutch forum : Have a look at the pics !!