black molly

I am sorry, but that doesn't help us narrow things down. Can you provide info such as, is your tank cycled yet? What are the water readings (ammonia, nitrite, nitrate, pH), and what were the circumstances of which you got the fish (did you dump the fish right into the tank), and how long have you had the fish?

We really need these answers completed to the fullest to determine what might have happened. ;)
 
Tank size, filtration, and cohabitants would be nice too.
 
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