I'm wondering if different pairs of coccina complex bettas could be kept together in a 4 gallon tank. Does anyone have any experience with it? I currently have a pair of betta Persephone, and I'm interested in getting a pair of betta Hendra.
I would say no. A 4 gallon is almost too small for a pair of B. Persephone; adding another pair would just increase aggression. There is also a possibility that they would crossbreed. @LittleBettaFish, second opinion?