i had an idea but wasnt 100% s i went as searched www.bettysplendens.com and found this
Rosetails
By: Joep van Esch
Submitted: 8/31/2005
Young copper/gold rosetail (6 weeks old) Young fish with extreme rosetail signs like the extensive branching in the caudal, small dorsal and ventral finnage
Blue rosetail HM with a 230 degree spread
In order to breed and develop the perfect halfmoon betta, betta breeders select their fish on several characteristics like straight rays/edges and multiple branching in order to breed fish which have balanced, well proportioned finnage. To accomplish this goal and to fixate these characterics breeding methods like inbreeding, linebreeding are often used.
The quest for the perfect halfmoon by this breeding method gave rise to a new development in the betta splendens tailforms, the rosetail.
The first rosetails mutants arose in 1989, when the CHENMASWIL team was developing the modern halfmoon. It was Jeff Wilson who gave them the name rosetail in 1991 [1]. There are many degrees of rosetails, from moderate to extreme forms (often referred to as fan- or feathertails).
The main characteristic of the rosetail is the excessive branching in all three unpaired fins. Especially the excessive branching and the overlapping rays in the caudal finnage results a 'rose-like' appearance, which explains the choice of the name. Other characteristics which are often seen with rosetails, especially with the more extreme forms, are smaller ventrals, a smaller dorsal, ligther colored bodies in comparison with the normal fish from the spawn, bad scales, slower growth and development. The extensive branching also often influences the swimming capabilities of these type of fish.
Most of the time the rosetail characteristics can be spotted very early in developing younsters. Especially the extreme forms already show fantastic finnage and impressive spread at a really young age in comparison to their normal siblings.
