When it comes to pure finnage, the Doubletail has it all. Not only is the caudal double with two tails, but the dorsal fin is also sports a double ray count. For meeting the IBC standard the tail split should be centered and the split should reach all the way to the tail base.
Is this trait dominant or recessive? How can the Double tail be used to improve the other tail types? Check out this collection of articles for answers.