My juvenile iguana has a black blotch on either side of his head that have surfaced fairly recently. He has a heat lamp and a uvb flourescent bulb. It is housed in a 30 gallon high tank and he is still fairly small. 3 1/2 inches from snout to vent. I was wondering if this is normal or not. The "temperature guage" on top of his head is not discolored.
thanks.

also. does anyone know about how old it is..... 3 1/2 inches from snout to vent. Thanks