The King of Wild Bettas, there is really not many wild bettas that is as beautiful and majestic as the Betta Macrostoma. These large mouthbrooders can grow till the size of 5 or 6 inches in the wild and should be kept in well filtered large aquariums with plants, driftwood and rocks. The ideal pH is 5.2 with a temperature of 25C. They will eat small shrimps, earthworms and high protein pellets. Weekly water change and monitoring of the water quality is essential to keeping these rare bettas in prime conditions.