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.
Habitat in the wild
At first it appeared not to be easy to bring these fish to Europe. The opaline gourami 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 fish. Without having the access to atmospheric air all fish survived only till the time when barrels were shipped.
After lots of vain attempts to bring opaline gourami 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 gourami were brought to the place of destination without any losses.
This is how 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 – is its complete twin and it inhabits in Asia, Indonesia, Sumatra, Thailand.
|Scientific Name||Trichopodus trichopterus|
|Common Names||Opaline gourami; marbled gourami; opaline fish|
|Ease of keeping||Easy|
|Lifespan||10 years and more|
|Tank size||200 liters (52 gallons) and more|
|Tank type||Community of fishes|
|Temperature||75–81 °F (24–27 °C)|
|Water hardness||9–20 dGH|
|Size||Up to 6 inches (15 cm)|
The opaline gourami 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. 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.
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 opaline gourami is smaller than that. Average opaline gourami 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 opaline gourami is good for community tanks, however male may have fights with each other or with some other fishes in a tank.
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.e. it should be neutral or faintly acid.
Tank size should be not less than 200 liters (52 gallons), the tanks should be spacious and well lit, thickly planted with dark bottom substrate. 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.
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 food can be used as a basic of the diet (flakes or granules).
It’d be perfect if there are several opaline gouramis in a tank, especially if there is a male and several female ones. Because, if there are few female in the tank or there aren’t any, male will fight with each other and get hurt.
Gender differences: male vs female
A very good approach to see between opaline gourami male and female is to raise juveniles from early days and observe the size of their dorsal. Opaline gourami 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 opaline gourami 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 opaline gourami couple. Put some small leaved fluctuant into it. The water in the tank should be fresh, settled during 2-3 days in advance.
To stimulate 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 opaline gourami 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 fluctuates. The nest may reach about 8 cm in diameter.
After that the male 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 squeezes the female 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 opaline gourami female from the spawning tank right after the breeding is over, since the male 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 opaline gourami 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 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 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.