my bettas fins look shredded as pictured below, any idea what it is? Are my red eyed tetras and albino cherry barbs nipping at her? Does she have some sort of disease (she is eating and still active, I see no ich or flukes on her)? Is this just how she is?
It's probley the afore mentioned fish doing it. Same thing happened to my first Betta. At first Betta pushed them around. Then they found the betta's weekness, air breathing. So as it goes up for air they ate all of his fins overnight. I forget what kind they were. But now I have Neon's and they leave my Betta alone.
My halfmoon chewed up his fins to half the original length when I was away on vacation. I guess he got hungry.
The split dorsal happens sometimes, IME it's not due to aggression. Looks like there was some nipping on the tail before, but it looks healed. The anal fin with a giant chunk taken out is weird. Your tankmates aren't big enough to do that.