disease identification

[Lusitano972]

hi all, can you help me identify this disease in my corydora??
1. Water parameters
a) Temperature range -26 degrees
b) pH 6.8 -7.0
c) GH 7
d) KH 6
e) Nitrate 0 Nitrite 0
f) Water change frequency 5 a 10 liters citerner tank day

2. Tank set up
a) Size 50 liters
b) Substrate. Sand
c) Filtration. Sump 700 liters Hours and 2 air filter
d) Furnishings.root, Echinodorus, anubia
e) Other tank mates.
6 Aeneus perou raye gold
10 leuomelas
8 SP C 30
6 reticulatos
6 napoensis
How long has it been set-up?
Tank set up 2 years.
15 days import fish purchase

when I got the fish, I put them in a tank of 50 liters for observation,
the corydoras aeneus were weak and colorless, I fed twice day with worms, pellets, tubifex, in three days I lost two fish. then lost one other, corydoras nopoensis had symptoms of holes in the head
aeneus Corys and still very weak , then decides to treat the worms one day with praziquantel, and fenbendazole 2 days, and saw some good results, a leucomelas died, and started a new treatment "sera med flagellol" to treat for 3 days.

now i have this problem and I hope you can help me thanks

[bigamefish]

it just looks like a well fed cory to me! my peppered cory looks like that and he`s ok! but i`ll leave the diagnoses to the corydoras pros!

[Vlacek]

I'd agree. This kind of pronounced belly was quite usual for panda corys I used to have. I wouldn't worry about it. What is a bit strange to me is body shape. Fish look unusually short compared to body high but this might be caused by camera and fish look a bit different in reality. How old are they?

[Lusitano972]

these fish bought them for 15 days import, and are in the quarantine tank, the size are young and had some losses, treated them with praziquantel and the worms to flubendazole, I now treat them with sera med flagellol. I see improvements but they were at the bottom without moving and without color.