GouramiThe term "gourami" is now widely used for any member of the family Osphronemidae, which occurs in both fresh and saltwater. Many popular aquarium species formerly classified as gouramis are now referred to by other names, e.g., bettas (Betta splendens), the Siamese fighting fish; anabantids (Anabantidae), such as the paradise fish; and labyrinth fishes (Cichlidae), which include the blood parrot cichlid (Nandopsis haitiensis).
Labyrinth fishes are so-called because of the complex maze of passages in their intestines. Gouramis are found throughout Southeast Asia, India, and Sri Lanka. Most species inhabit swamps and ponds, although a few live in brackish water or rivers. The giant gourami (Osphronemus goramy) is a freshwater species that has been widely introduced into the tropics outside of its native range.
Gouramis are labyrinth fishes that do not have a stomach in the usual sense, with one exception—the moonlight gourami (Trichopodus microstomus), which belongs to a group of osphronemids known as the snake-skin gouramis. In this species, in contrast to most labyrinth fishes, there is a well-developed stomach in which digestion occurs externally; food passes directly from the stomach into a section of the intestine and then directly into the body cavity.
Gouramis are usually kept singly or in pairs, although they are social fish that will shoal when given a choice. Most species can be kept together, but males may fight to death over territory or access to females. Gouramis are carnivorous and require a high-protein diet of live foods such as bloodworms (chironomid larvae), brine shrimp, and chopped earthworms; frozen or freeze-dried tubifex worms are also used. Flake foods are not an acceptable diet for gouramis since they cannot digest plant products efficiently.
Gouramis lay their eggs in a bubble nest, which is attached to aquatic plants, rocks, or other objects at the water's surface. The male fish cares for the eggs and fry (young fish).
Colorful gouramis that are too large to be kept in a standard aquarium can be successfully housed in outdoor ponds. They grow rapidly, however, and should not be permanently housed in small ponds; thus some breeders keep them in larger containers and release them into ornamental pools for display only. The giant gourami (O. goramy) is the largest species, reaching a length of almost 1 metre (3 feet). All other species are less than 50 cm (20 inches) long.