Please help identify this fish.

[Lynsey]

Sorry for the really bad pic. but it is the best I could do. These fish were sold to me as silver dollars, but two of them look slightly different. One of them has red on its face and under its gills. I am hoping that it is not a pacu or something that gets super big like that. I think it is just a different species of silver dollar, but what do you think.

http://image1ex.villagephotos.com/1796825.jpg

[swreefer]

Pacu.

[Lynsey]

After looking a bit more, It sort of looks like a Metynnis hypsauchen. It has dark spots on its dorsal fin too.

[missinglinks14]

Reddish one looks pretty close to a red bellied piranha. It is probably a Pacu.