my blackmoor is dieng but why?

my blackmoor fish is dieng i noticed one of its eyes was a bit swollen and a whitish colour and half an hour later i looked and hes floating and not moving i think its dead but im not sure and i dont understand why??
and also before only it was swiming around but now it is dead i think the other two fish are swiming about more!
please help me!

 

please please please please

somebody reply i really want to know why this happend

 

it all depends on the tank size. you haaaaaaaave to have at least a 10 gal tank and you can only have 2 other fish in the tank if its a 10 gal tank. plus did you now that the moor is won of the most dirtiest fish in the world other than a beta?????????? also the moors' scales turn orange like a goldfishes wen it gets old. wen the moors eye got swolen,it was because of an infection so i wud suggest you give it sum medicine to treat the eye.

 

umm did u read what....

did u read what i said?? it died within the day that its eye got swallen n my 2 ova fish r fine!