Apparently human conjoined twins are always genetically identical.

"In short, conjoined twins occur when a fertilized egg procrastinates a division. If an egg splits in the first twelve days after conception, identical separate twins are created. If it waits until the thirteenth day or later, the embryos do not divide completely. This leaves the twins conjoined. They can be connected by a ligament, as were the original Siamese twins, Change and Eng Bunker, or attached even closer – at the head, chest, rear end, or lower body.
It is estimated that only one in 200,000 live births will result in conjoined twins. Approximately seventy percent of conjoined twins are female, though it is not known why. Conjoined twins are always the same sex, never mixed."



Can't wait to see the DNA results on CM's king to see how it works in the fish world.