Common name: Giant Gourami Scientific name: Osphronemus gourami
Distribution: The Greater Sunda Islands, China, Java, Malaysia and Indochina.
In captivity, this fish rarely exceeds 24 inches (61 cm) depending on tank size.
In the wild however it can exceed 36 inches (1 metre).
Young fish are essentially triangular in profile, but this changes as the fish matures.
The forehead becomes convex and develops a fatty hump. The head is relatively small in comparison to the body. The fish has a large mouth with a protruding lower jaw which is ideally suited for browsing on aquatic vegetation.
Juveniles are brightly coloured, usually reddish brown with many vertical stripes on the sides of the body.
The dark colouring tends to fade with age and most adult Osphronemus tend to be rather dull in colour.
The ventral fins are yellow-brown and as in all anabantids are elongated into long trailing filaments.
The sexes can be distinguished by the shape of the dorsal and anal fins.
In the male, these fins become pointed towards the rear.
The female is more robust and the above mentioned fins are rounded.
Temperature: 63 -81oF (17 -27oC) higher for breeding. pH and Hardness: no specific requirements (neutral). This fish prefers a very large roomy tank so they have enough room to move around, also thickly planted with both rooted and floating plants (be prepared to replace the plants regularly). Water should be well filtered and not extremely hard or extremely soft.
Food: Omnivorous. Fresh or frozen meaty foods, also plenty of vegetable matter such as
Peas, Cucumber etc.
In the aquarium, the behaviour of this species is similar to that of the smaller gouramis. Although they grow rather large within a short time, they can be kept with other peaceful species even some considerably smaller than themselves. Beware though, if there is a shortage of food they may well attack weaker members of their community.
To breed this rather large fish will require an extremely large tank.
Like all Anabantids, the male will build a large bubble nest and strengthen it with plant parts, therefore plenty of floating plants should be put on the waters surface to assists.
Well fed females should fill up with eggs within their first year, sometimes even earlier. Spawning is easily triggered by raising the temperature of the water to 86oF.
Up to 1,500 eggs are released which are rich with oil and immediately rise to the water surface. Fry hatch after 35 to 40 hours but do not become free swimming for about 10 to 12 days at which time they should be fed on pulverised live food and newly hatched Brine Shrimp.
The Giant Gourami, the world's largest anabantoid, is often exported and stocked as a food fish.
The species will tolerate sudden changes in temperature and does not react badly to sudden changes to the chemical composition of the water, particularly the pH. This is probably a good thing if you think of the problems you could face when trying to move a fish of this size!
It can also breath atmospheric air using its respiratory organ called a labyrinth.
The picture on the right shows a brightly coloured adult
Osphronemus with an unusual amount of red in the fins.
It's a shame that this is not a more common sight.
This article first appeared in the Newsletter of Dunstable & D.A.S.