58 Pa. Code § 63.42
It is unlawful for a person to sell, purchase, offer for sale or barter any fish parts or fish eggs obtained from fish taken from the waters of this Commonwealth, including boundary waters. This prohibition does not apply to fish parts and fish eggs lawfully taken and sold or offered for sale by holders of commercial fishing licenses under Chapter 29 of the code (relating to special licenses and permits), if the particular species of fish is authorized for taking by commercial licensees. This prohibition does not apply to the sale, purchase, offer for sale or barter of fish parts and fish eggs legally obtained from fish taken lawfully from waters outside this Commonwealth, if the seller or purchaser is able to document the source of the fish parts or fish eggs from lawful sources outside this Commonwealth.
58 Pa. Code § 63.42