Ill Masked Corydoras

[Kehza]

Tank Size : 125 Litres 
PH : 7.4 
Ammonia : 0ppm 
Nitrite : 0ppm
KH : N/A 
GH : N/A 
Temperature : 27 Degrees/81F 
Tank Mates : 5 Various Corydoras, 4 Green Barbs, 4 Electric Blue Ram, 1 Bullnose Pleco, 1 Bristlenose Pleco
 
Basically about two months ago my Corys were moved into a new tank. During the move my Masked Cory appeared to have a bit of a lump under his belly, at first I was worried it was a fungal or external bacterial infection. A lot of research later I couldn't find any diseases matching it's symptoms and appearance. After talking to my local fish store about it on many occasions they said it is likely to be cancer/tumor. None of the other fish had exhibited any of the symptoms even after 2 weeks and all are healthy, and the Corys personality remains unchanged, there's no loss of appetite, activity, no rapid breathing etc. 
 
So I came to the conclusion it was infact cancer/tumor as my Betta fish from a separate tank had something very similar and lived a long happy life. 
Yesterday for unknown reasons I lost one of my bullnose plecos, he literally dropped dead in front of my eyes, with no concerning symptoms etc. After inspection he seemed rather bloated so I'm a bit worried the Corydoras has something contagious, the lump is rather large at this stage too. (Poor guy =( ).
 
<Please see the image attached> 
 
The only two diseases that I could possibly line it down to are, cotton mouth (to my eyes the lump is solid, and no fungus is apparent around the mouth or on other fish) and lymphocystis but the lump is in one area only. 
 
Could someone confirm my findings? Has the masked Corydoras got a disease? Thanks in Advance. 

 

[DoubleDutch]

Indeed looks like a tumor to me. Most other mentioned diseases have whitish ulcers / spots as symptoms. Fish conditions looks okay either !!!
Problem about tumors with Corys : If they grow (partly) internal, there is hardly no way out (no scales), so pressure could start to build up in the fish.
But in that case other symptoms appear (less of appetite, bulging eyes aso). As long it doesn't show these, i'd let it (keep a close eye on it).

 

[Kehza]

One recent difference with the lump is that there is a sort of white bubble to it (opposite side to photo)? Well lighter than the current colour, I'll try to get a picture but he's not the stillest of fishes  
 
Iv been keeping a close eye on all the fish since his illness. Two of the Cories do seem a bit less active compared to how they were in the old tank, however this is only during daytime and their "shoal* is a little small considering the size of the tank and them being a group of 5.
 
Thank you for the response by the way  

 

[Kehza]

Does anyone else have any opinions by the way..? 

 

[mark4785]

It does look like the Corydoras has some sort of internal issue that resembles a tumour. It definitely resembles the tumour that my Auntie's goldfish had and that fish was able to live with it for about 6 months.
 
The only real cure for this would be to take the fish to a qualified Veterinarian who can diagnose and physically remove the tumour.
If this isn't an option I would recommend feeding the fish the best quality food, occasionally supplementing the food with multi-vitamins so as to prolong it's life.
 
Are you cleaning your tank with bleach or any compounds that you'd normally use around the house to clean things? I have a hunch that tumours in fish are brought about by harsh chemicals mixing in with the tank water.

 

[Kehza]

Oh gosh no, no harm chemicals. The only "chemical" that has touched the tank are water treatments, nothing more.