The giant gourami (Osphronemus goramy) is a gourami, a freshwater fish belonging to the subfamily Osphroneminae in the family Osphronemidae. Some other larger members of this family are also occasionally or regionally referred to as "giant gouramis", including the banded gourami, Trichogaster fasciatus, and the three spot gourami, Trichopodus trichopterus. In turn, the giant gourami is also sometimes known as the banded gourami, rainbow gourami, or striped gourami.
Giant gourami build nests using weeds and twigs. Females can be identified by their thicker lips. The giant gourami is native to parts of Indochina, Malaysia, Indonesia, and India, but has been introduced elsewhere for the purpose of aquaculture.
It lives in fresh or brackish water, particularly slow-moving areas such as swamps, lakes, and large rivers. It is capable of breathing moist air, so can survive out of water for long periods. It is much larger than most gouramis, growing to a maximum length of 70 cm (28 in). In colour, it is a pale to golden yellow, with silvery pale blue stripes running vertically along its body.
Partly in consequence of its size, the giant gourami is a significant food fish, and in its native regions it has been harvested as a customary food source. In some parts of India, it is dried and then eaten. It is also a popular food fish in Indonesian and Malaysian cuisines. The species has also been used for weed control as it can be a voracious herbivore.
The giant gourami is also popular in aquaria. Preferably, the tank should have a dark bottom, and densely planted edges, with room left in the center of the tank for them to swim. They prefer the company of other fish of similar sizes and temperament. They are easy to keep at three months old at around 7.5 cm or 3 in long.
At this age, they have a pronounced beak. They can grow rapidly given sufficient food and space to move. Even under less than ideal conditions, gourami can grow from 7.5 cm to 50 cm in four years. At this age, in addition to the rounded face, a mature giant gourami would have begun to develop the hump just above its eyes.
The gourami, in a community tank, will snap and charge any other fish which are small enough for it to bully. Like most aquarium dwellers, giant gourami can be quickly raised with larger, more passive fish. However, if other fish are added to a tank, either large or small, they might be killed within a short period.
Gourami tend towards herbivory, preferring algae-based foods, but will eat meaty foods. An algae-based flake food, along with freeze-dried bloodworms, tubifex, and brine shrimp, provides these fish with the proper nutrition while young. Once of significant size, they can be fed legumes, partially or fully cooked fibrous or starchy vegetables, or fruits.
The giant gourami is an egg layer, and the male will build a bubblenest before spawning. The male and female are distinguished by the dorsal fins and body color. The dorsal fin on the male ends in a point, and the body is darker changing to nearly black during spawning. When breeding, the water in the tank should be decreased to about 20 cm (8 in) deep and the temperature should be 28°C (82°F). After spawning, the female should be removed to a separate tank as the male will jealously guard the eggs, in a captive environment, sometimes becoming aggressive towards the female. The eggs hatch in 24 hours. They must be kept in a dark aquarium.