Could this be bacterial?

[FishDog]

My flower which I have had for 2 weeks now has moved up the food chain and is the second most aggressive eater in the tank. My female castexi is number 1. She still needs some more weight on her, but she eats like a pig so any day now. I noticed this pink spot in the pics about 4 days ago. The spot is not raised, just looks like a darker pink spot. I am worried it may be a bacterial infection cause it is visible top and bottom. What do you guys think? What would be the best treatment and is there a new way that won't destroy my filter bed? The spot is on the right front of her disk.

 

[FishDog]

Here is another pic.

 

[skynoch]

looks more like a bite mark than bacterial.

 

[Panerai1950]

Im pretty sure that its bite marks, bacterial infection looks different, like the pic below. Ur ray is really thin, give more food to him b4 he stops eating...

 

[FishDog]

I got her 2 weeks ago and she was a lot thinner then. She is eating 3 times a day and on the road to getting fatter.

 

[Panerai1950]

I got her 2 weeks ago and she was a lot thinner then. She is eating 3 times a day and on the road to getting fatter.

cool, thats nice to hear, i found stingray hard to eat again after they stop

 

[Nic]

not bacterial.... looks like a bite mark