CORYDORAS JULII - DEAD

[Ray.M]

I bought two Julii from the LFS. Both seemed very healthy but one was relatively quite but the other one was 'hyper' swimming up and down the glass. On the third day I found the hyper one dead - physically the fish looked good.
All my other fish are fine and the water parameters seem OK.
Any ideas why it died and what I should check?
I have four other corys and they are all OK.
I had the last Julii for 8 years before it died a couple of weeks ago.

Thanks,
Ray

[Mr Wild]

No idea with that info - what other fish do you have in your tank?
This is why qt is important what if they have brought something to your tank?
No way of knowing.