The Blue Gourami is a very hardy and popular fish in the community aquarium. They are often chosen by those starting out in the aquarium hobby. They can grow to a rather large size up to 3 or 4 inches. The males can be territorial , and will occasionally bully other fish. They do well in tanks that have medium sized fish, or in well planted aquariums. You can sex gouramis by their dorsal fins (upper). The long pointed dorsal fins are males , and the short rounded dorsal fins are females. The Blue Gourami is a labyrinth fish. They can break the surface , and breath air directly. Like other labyrinth fish the male blows a bubble nest to breed.