Here is a picture of the Asiatica that can be found (rarely) around Sakishima Island, Okinawa.
I see many similarities to this, and I believe your fish is this Asiatica.
These are very hard to find, and I have been told they ONLY exist (this morph) on Sakishima Island.
I also believe the head shape is different to the fish posted here due to sex, and also age. I think your fish has some good age to it.
Any idea of the catch location and how old it is?
Either way, you got a very special fish, enjoy it!