Originally Posted by JikoJiko
I don't even know what that really means...
Is that like how my Males spine are like alittle arch... From my photos>>>???
The top line isn't curved smoothly from tail to head. Usually under the dorsal there's a significant "bending"(?) making the betta sort of hunched back - bent spine. Slight bending, though undesired, is acceptable. But extreme bending and specially if it causes swimming issues, is unacceptable. These should not be bred as it may be genetic.
Both male and female can have bent spine. Your PK male is slightly bent, but acceptable - not enough to be considered "bent". "Bent spine" bends even more.
Over breeding DT x DT often causes these bent spine - the reason why you should breed DT to a single tail then breed the genos to get your DT.
Hope that gives you an idea.