Flowerhorn is a hybrid species between many kinds of cichlid fish.

The popular flowerhorn nowaday is Kamfa F1, F2, F3, Golden Base, Kamalau, Thai Red, Thaisilk,...

Kamfa is the most expensive fish because it is beautiful and very hard to generate this kind of flowerhorn. 

F1 flowerhorn cichlid thats mean his mother is Vieja Synspilum or Texas cichlid (F0 generation), father is Thai red. 

And continue to F2, F3,...

Because Vieja has no big kok so F1 fish usually does not have a big head too. After F1 is F2. This generation has both of 2 advantages of Texas cichlid (which has full pearl) and Thai red (which has red color and big kok). And you know, very hard to make these fish to marry together. :))