Sick Cory, Advice Needed!

[tomchurchman]

Had our 2 schwartzi corydoras for 2 weeks now, one is fine and the other has been a little subdued for the past week, anyway yesterday evening we noticed him just laying on the bottom of the tank, almost lifeless, every now and then he has a little mad dash around and lays back down on the bottom, sometimes on his side, he is also looking very thin and pale, all other fish in the tank (4 honey gourami, 3 zebra danio's and 3 endlers) are fine. Did a 1/3rd water change this morning, last had my water checked 10 days ago and it was spot on.
Someone help please! he looks like he's about had it!

 

[WILDER]

No hes not well, has he gone thin through not eating.

 

[tomchurchman]

well, he died last night. and had been eating up until a couple of days ago. A bit worred about my remaining fish.