Is my Molly sick?

I have 8 small mollies in a 40 gallon tank, everythings been wonderdul. Ammonia, nitrite, ph, is all right where it should be. Today I couldn't find one, I didn't pay much mind. He/she came out during feeding and was swimming along on the bottom, looking real weak. The fish even looked a bit transparent. I took him out and put him in my spare 10 gallon tank right after taking this photo. Any one have any ideas on what's going on?

Thanks in advance

 

Hello is your tank cycled? What are your readings? Do you only have 8 small mollies?

 

Looks like major finrot on the tail fin for sure & maybe sunken belly... Or at least in the picture view. What are your exact water parameters? And are the mollies only ones in the 40 gallon tank?

 

Lucy I would close the thread because the op isn't ever on.

 

HI Sarah
We'll leave it open. Tug may return.
Threads will close on their own if there is no activity after a certain period of time.

 

HI Sarah
We'll leave it open. Tug may return.
Threads will close on their own if there is no activity after a certain period of time.

Okay thanks!