Orange Gator!

[A. gigas]

It's more than likely Iron Oxide, especially if that Gator is a transient Male........Iron Oxide is the orange sludge you see in stagnant Canals or Ditches, and it does stain......Every now and then you'll see a Turtle picture pop up with the same thing........

i agree, i only said it was a slight possibility

 

[mqktandy]

It's def iron oxide stain...look around the eyes. The one area they keep out of the water when they swim and it's normal colored. Still pretty neat