Opaline gourami (Trichopodus trichopterus)

Opaline gourami is a very beautiful color-morph of three spot gourami (Trichopodus trichopterus). All kinds of gourami belong to Anabantoidei suborder and they are also commonly called as – labyrinth fish.

They got this name first of all due to the additional respiratory organ they possess – it is so called “labyrinth organ”, which is located in epibranchial space and formed by the folds of membrane that covers the bone.

This thin tissue has lots of capillary vessels and as for its functions – it resembles lungs of land animals. If labyrinth fish have no access to atmospheric air, they get suffocated, because their gills don’t provide them with the necessary amount of air.


Habitat in the wild

At first it appeared not to be easy to bring these fish to Europe. The fish was caught in Thailand and Vietnam, on Malaysia islands, however the fish couldn’t stand even a day of transportation and it died.

At those days any exotic fish were transported in a very common way – in wooden barrels filled with water up to the brim.

Very few people knew about the peculiarity labyrinth fish had, however at the same time in Paris Paul Carbonnier had studied and successfully bred Paradise gourami.

Without having the access to atmospheric air all gourami fish survived only till the time when barrels were shipped.

After lots of vain attempts to bring opaline gouramis to Europe, the fish were labeled as troublesome and for the next 20 years people stopped trying to spread them.

Onlookers were puzzled: in the wild the fish was encountered in some rain barrels, gutters, abandoned open pits with terribly dirty and muddy water – so what did they miss during transportation?!

Only at the very end of 19 century some witty guy from Europe has noticed when observing these fanciful fish in their natural habitat, that they occasionally come up to the water surface to get some air bubbles.

So, he followed the advice of his Indonesian guide and filled only two-thirds of his transportation barrels with water and he didn’t close them tightly. As a result, several thousands of opaline gourami were brought to the place of destination without any losses.

This is how gourami Trichogaster trichopterus (Pallas, 1977) came to Europe in 1896. The fish became very popular and almost right after that they were successfully bred. Since gourami is an artificially bred color-morph, it can’t be encountered in the wild.

However, its ancestor – blue opaline gourami is its complete twin and it inhabits in Asia, Indonesia, Sumatra, Thailand.


The fish has an elongated body, flattened from sides with large rounded fins. Its pelvic fins have turned into thin barbs which have some sensitive parts and so they are used by the fish to get some info about its environment.

Just like all labyrinth fish the opaline gourami can breathe with atmospheric oxygen, that helps it to survive at some unfavorable conditions.

Opaline gourami has a very beautiful body color, especially male when its exited.

Their dark blue colored body with some dark spots scattered on it resembles real marble pattern – due to this the fish got its name.

This is quite a large fish and max size may be up to 15 cm (6 in), however in general the fish is smaller than that. Average lifespan is about 4-6 years

Difficulties in keeping

The fish is rather not demanding, care is quite easy, therefore it can be recommended to beginners. It’s not demanding as for the feed and it can get used to any tank conditions.

The fish is good for community tanks, however male may have fights with each other or with some other fishes in a tank.

Care and keeping in a tank

Both opaline gourami and all its color-morphs are really surprisingly not demanding ones. They can do with rather wide range of water temperature, however the optimal one is 75–81 °F (24–27 °C).

Chemical composition of the tank water isn’t very important – pH should be 6…7, i.е. it should be neutral or faintly acid.

Tank size should be not less than 10 gallons, the tanks should be spacious and well lit, thickly planted with dark bottom substrate.

Scientific NameTrichopodus trichopterus
Common NameOpaline gourami, marbled gourami
Tank size10 gallons (40L) and more
Temperature75–81 °F (24–27 °C)
Size6 inches (15 cm)

There must be a lid on the tank, since opaline gourami just like all other labyrinth fish get up to the water surface from time to time to get some atmospheric air, and namely because of that the temperature of the air above the water must be constant and only slightly different from the tank water temperature.


Opaline gourami is an omnivorous fish, in the wild it feeds on insects and their larva. In a tank it can be fed with all types of feed – live, frozen and artificial one.

Some special fish food can be used as a basic of the fish diet (flakes or granules).

If you (just like me) regularly feed your fish with artificial food, then the links will be very helpful for you – HIKARI Micro Pellets, API Fish Food Pellets, Fluval Bug Bites, Zoo Med Spirulina. I know what it’s like when you pet fish die because of low quality food or get ill due to infection ingress into the tank with live food. I myself give some of this food to my pets and as for the rest I’ve heard and read lots of good reviews. Yet, all of the food is of high quality and it is the best one for this fish kind as well as it keeps the tank water clean.


Are very peaceful and calm ones, therefore they are perfectly compatible with all other fish kinds. clown loach, guppy, dwarf gourami, betta can be opaline gourami tankmates.

It’d be perfect if there are several opaline gouramis in a tank, especially if there is a male fish and several female ones.

Because, if there are few female fish in the tank or there aren’t any, male will fight with each other and get hurt.

Sex differences

A very good approach to see between male and female fish of Trichogaster kind is to raise gourami juveniles from early days and observe the size of their dorsal.

Male has a long and sharpened dorsal, usually when it is lowered and lays on the fish back, it reaches the place where its fluke fin sets.

The female fish usually have short dorsal. Besides, reproductive females are smaller than males and they have more rounded abdomen.


To get offspring successfully you’ll need a specialized spawning tank of at least 5 gallons capacity for a fish couple. Put some small leaved fluctuants into it. The water in the tank should be fresh, settled during 2-3 days in advance.

To stimulate oplaline gourami breeding you should raise the water temperature up to 26-28 degrees. The water hardness should be about 6−7 ph, acidity – up to 15 dh.

The fish need complete peace in the tank, so close the tank walls with some paper or cloth.

Breeding is quite an interesting process: first the male fish makes a nest of bubbles on the water surface free from any fluctuants. The nest may reach about 8 cm in diameter.

After that the male fish starts haunting the female one and then the spawning starts. Male curves and embraces the female at the same time turning her abdomen in the direction of the nest.

When curving the male fish squeezes the female fish abdomen and the eggs come out and go up to the water surface. It should be noticed, that this fish kind may lay about 1000 eggs when spawning.

You should remove the female fish from the spawning tank right after the breeding is over, since the male fish takes care of the eggs. Larva appear 2 days later. Male keeps an eye on its juveniles all the time by bringing back to the nest the larva that fell down from it.

In 4 days the larva get spread around the spawning tank and this is the time to remove male from the tank, since he may easily eat the juveniles.

Juveniles should be fed with infusorians and rotifers – they are the smallest of live fish food. After removing the male fish from the tank, also remove the fluctuants, decrease the water level up to 10-15 cm and start water aeration.

Once the juveniles’ labyrinth organ is completely developed they’ll start to come up to the water surface to get some air with their mouth. The water level should be risen continuously.

Also, you should take into account that oplaine gouramis juveniles grow at different rate, so cannibalism might appear among them.

Therefore, the juveniles should be sorted according to their size all the time.

Half of the tank water should be renewed once a week with some amount of clean, settled and aerated during 2 days water.