Gender Differences
The breeding of this mouthbrooders is relatively easy, provided one has a harmonizing couple. Pairing should be allowed to occur naturally within a group, otherwise complications might arise as the sey of the fish is often difficult to determine. During breeding season, females are fuller than the males because of the spawn. The sex differences of channa spec. 'Assam' can be determined relatively well by comparing the individual from bird's eye view. The male' s head is broader, especially in the gill area. The female's body color contains more red and her fins are not as blue as the male's. Determining the sex of the fish by comparing head forms also works well for channa bleheri. I suspect the same to be true for channa orientalis, and channa gachua, as well as for their close relatives. 4
courtesy of snakeheads.org