Help, Little Platty Injured.

I have 2 plattys and 2 silver mollys. One of the plattys is quite small in comparison to the other. I have just noticed that my smaller platty was laying at the bottom of the tank. I could see from the reflection that it looked as if he'd been bitten. It is a small area on his side thats white, with a bit of red around it. I have got him out just incase. Please help. I don't know what it is. Ive also just seen babies in the tank. Could that be the problem?? Ive attached a picture.

Looks just like a simple rough-housing scar. Try and keep him in quarentine and put some Melafix (found at your lfs) in to treat the open wounds. It's really important to isolate him, not only because your fish will probably take advantage of his weakened state but also because the fish will continuously peck at his wound and make it get worse over time.

Wounds that are white on the edges and red in the center are most typically Aeromonas. Those that are red on the edges and white in the center are generally Columnaris. Both are gram negative bacteria. The best treatment for this is any sulfa antibiotic with trimetheprim. This can be put in the water and/or mixed with food -- if you can find Romet B use it.


Taken from this link.
http/www.fishpalace.org/danscomments.html#Lump