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Pair of chocolate gourami.

Chocolate gourami are a beautiful fish who look really nice in a blackwater aquarium. They also come with a reputation of being difficult to simply keep alive.

A year ago, I was lucky enough to be given a trio of chocolates and they have done well. So I thought I might share how this was achieved.

In the wild, chocolate gourami can be found in the same waters as the licorice gourami.

Essentially, chocolate gourami require the same soft acidic bacteria free water; a blackwater environment.

Chocolates are very aware of what is happening on the outside of their aquarium. They will watch you.

Chocolates need a quiet environment away from loud noises, constant traffic, boisterous children, and without too bright a lighting.

They are also very shy, especially when you try to photograph them. Every time I would set up my camera while courting prior to spawning, they would look at the camera lens and move to a new location.

Chocolates also have a definite pecking order and bullying does occur. This is another reason for plenty of retreats out of sight of tank mates and what is outside their aquarium.


The aquarium pictured below is home for my trio of chocolate gourami. Tannins released from the wood give the brownish hue to the water - the "blackwater" look.


My aquarium housing chocolate gourami.


The substrate is creek sand about a centimeter or so deep.

Plants are all attached to the wood with nothing growing in the sand.

This is a modular approach. Everything within the aquarium can be replaced without disturbing the fish. I have actually siphoned the sand and replaced it completely without disturbing anything else.

The plants used in the photo above are Anubias nana, Anubias baxteri, Microsorum pteropus 'Windeløv', Lomariopsis lineata (Süßwassertang).

On the right are a few Indian almond leaves

Male and female chocolate gourami.

Water is the same as I use for my licorice gourami.

I use RO water set to as close to zero hardness as possible for water changes.

I have two 15 litre containers set aside. The water is treated with declorinator, acidity is lowered using an acid buffer. An air-stone for aeration and then left until I am ready to use it. Usually a week later. Aged water seems best.

The pH of water in the containers is lowered to between 4 and 5.

I try for a 20 percent water change a week. Though admittedly, sometimes a week can become a fortnight.

Though the chocolate gourami seem to do well between a pH of 4 and 6, I aim for a pH of 5. From what I understand the pH is not critical, but rather it is the microbiological cleanliness that counts.

When you browse the forums over at the Parosphromenus Project and elsewhere, you find references that chocolate gourami don't do well with carbonate hardness.

The Seachem company make a product called Acid Buffer which, according to the label, is phosphate free and lowers pH by changing carbonates into carbon dioxide.

Filtration is a small airlift sponge filter with the air turned down fairly low.

The filters are not rinsed or cleaned to preserve the helpful bacteria who manage to survive in the acidic water.

Water temperature is set to 26 degrees Celsius.

Lighting is variable LED. The variable LED lights allow adjustments to the light intensity to a level where chocolates will spend most of their time in the open and yet the plants will grow as well. My guess is the floating plants and an open tangle of wood with plants gives the chocolates a sense of security.

Chocolate gourami really like their food.

I feed my chocolates both frozen and live foods.

Live mosquito wrigglers, daphnia, grindle worms, and brine shrimp are all enjoyed. Thawed and rinsed frozen foods include the blood worms and adult brine shrimp.


The literature is rather vague on how to sex Sphaerichthys osphromenoides. Probably because there have been so few spawning in captivity and few people really know.

Two chocolate gourami courting.

However, if you see the tight circling behavior with bellies dragging on the ground, it is probably safe to say those fish are a pair; male and female. It is also probably safe to say they will spawn sooner or later. Given the right water and food.

The tight circling courtship on the bottom of the aquarium can last for days. The constant circling with bellies dragging on the sand forms small depressions perhaps five millimetre deep and 50 millimetre across. From observation spawning takes place over these depressions.

Watching the spawning is interesting. Basically the two fish circle close to the ground for an hour. Differences become apparent closer to the actual spawning. One fish which I presume is the female becomes paler. The other fish, presumably the male, extends the throat and gills, presumably to accommodate the eggs.


Male chocolate gourami picking up eggs.

Chocolate gourami after spawning.

Male chocolate gourami with extended throat brooding eggs.


The egg count is approximately fifty eggs.

Water parameters on the day of spawning:

  • pH of about 4.9.
  • KH and GH are both as low as possible.
  • 27° Celcius.
  • Two large Indian almond leaves are always present.
  • Lighting is minimal.

The spawnings I have seen all took place between 8pm and 9:30pm.


The spawning took place on the evening of the third of September. The first fry were seen on the morning of the seventeenth. So thirteen days brooding. At this point in time, the evening of the seventeenth, the fish is still holding fry.

So fourteen days brooding for Sphaerichthys osphromenoides from the time they pick up the eggs to when the fry are released.


Riccia with ruler for size comparison.

Size comparison: Riccia is 1mm wide.

tiny chocolate gourami on water surface among floating plants.

Photo taken from above. The plant is Riccia.

Given that the Riccia stem is 1mm wide, the one day old fry are approximately 6 or 7mm long from nose to base of the tail.

tiny chocolate gourami among floating plants.

Side view of 3 day old fry.

The fry are with the adult chocolate gourami within the layer of floating plants.

Riccia does not seem to survive for long in very acidic water, perhaps a week or two. The idea was to give plenty of cover for the new fry on the first few days until I decided what to do; raise separately or leave alone.

As things turned out, some fry have been placed in a netted enclosure and some fry are left to grow within the floating plants. This will give an indication of whether or not chocolate gourami will hunt and eat the fry. Or if they will behave as many other gourami family mouth brooders do and show little interest in eating their offspring.

From observation, the fry easily eat newly hatched brine shrimp and micro-worms. Though brine shrimp will move towards the light which is above the surface and that is where the fry are. Also the adult chocolate gourami below will eat the brine shrimp that fall towards the bottom. Micro-worms on the other hand tend to sink.

tiny chocolate gourami yawning.

That mouth is as big as it's eye.

Using the camera as a microscope to view the fry also shows an abundance of cyclops and other small rotifers living within the layer of floating plants. There are enough of these tiny creatures moving about that the fry can stay motionless and the food comes to them. So a balanced diet even if I leave out the micro-worms. Perhaps when the fry leave the surface, I will reintroduce the micro-worms.

There is a lot to learn about chocolate gourami raising and behavior, and there will always be more spawnings to video and photograph.

Day ten since the male released his brood. Where the fry previously stayed at the surface within the plant cover, they are now venturing into mid water. I have seen the adults rush up and stop within a few centimetres of the fry. The fry darts off and the adults loose interest and go about their business again. Clearly the adults do not see the fry as food. Perhaps this is a mouth brooder instinct not to eat their offspring. The Betta albimarginata are the same; the fry are not eaten and multiple generations can be brought up together - the colony aquarium.


Three very small chocolate gourami with adult.

Adult with three fry eating brine shrimp mid water.

Very small chocolate gourami near leaf.

Fry are out and about in the open water at ten days old.


The strategy now is to follow the colony path and just leave the fry together with the adults. A layer of floating plants to provide cover.

Brine shrimp are attracted to light and will move towards the surface where the fry are; the perfect food for what is wanted here. Brine shrimp are simply distributed with an eyedropper among the floating plants. The adult gourami below eat all the brine shrimp that fall to mid water.




Is Sphaerichthys osphromenoides a maternal or paternal mouth brooder?

When you read the available literature, Sphaerichthys osphromenoides and Sphaerichthys selatanensis are said to be maternal mouth brooders. That is to say; the female picks up the eggs and broods them.

It is also widely stated that all the other gourami are paternal mouth brooders. That is to say; the male picks up the eggs and broods them.

However, when I watch Sphaerichthys osphromenoides spawning, it looks to me like the male is the fish who picks up the eggs and broods the fry.

The question of maternal verses paternal mouth brooding in Sphaerichthys osphromenoides looks to be alive and well . . .

. . . and I like a good mystery to solve.

The spawning pair of chocolate gourami.

The two spawning fish. The female on the left is still in shock after spawning. The male is picking up the eggs.

It should be noted that the following photos are from the same spawning. This is also an earlier spawning than the photos in the section above.

Chocolate gourami spawn in a matter of moments, all the eggs are laid in a single embrace. If you look away for a few seconds, it is over. Documenting a spawning on video is difficult.

My first attempt to video a spawning had my camera set up ready to go and after hours of watching, I was distracted for a few minutes and it was all over when I returned.

However, I did manage to grab my camera and take a few interesting, though less than conclusive photos post spawning.

Chocolate gourami can be difficult to tell apart. However the markings are sometimes very individual as can be seen in the two photos below.


male chocolate gourami.

The fish on the right in photo above.

female chocolate gourami.

The fish on the left in photo above.


Male chocolate gourami with extended throat holding eggs.

Male, the morning after spawning.

Female chocolate gourami eating.

Female, the morning after spawning.

What needs to be done now is to video an entire spawning and identify exactly who lays the eggs, and exactly who picks the eggs up and broods them for two weeks.

We need conclusive evidence.

. . . . and here it is:

In the video below are the two fish pictured above spawning. It is very clear exactly who lays the eggs and who picks the eggs up afterwards.

As can be seen from the video; Sphaerichthys osphromenoides is NOT a maternal mouth brooder.

The male incubates the eggs and fry in his mouth.

To be fair; osphromenoides is a difficult fish to keep successfully. The fish are also shy and reclusive when spawning, and eggs are all laid within a few seconds. If you blink; the act of spawning is over and you have missed the important details of who actually laid the eggs and who actually picked the eggs up.

Maternal mouth brooding in Sphaerichthys osphromenoides is a myth.



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Suggested Reading

parosphromenus project logoParosphromenus Project (external link)

Parosphromenus Project (external link)

The Parosphromenus Project was founded in 2005 in Germany and has grown to be a worldwide project to study and preserve the licorice gourami within the aquarium hobby.

There you will find everything about the keeping and breeding of the licorice gourami.

Highly recommended as essential reading if you wish to keep the Parosphromenus.

The Science of Aquariums (external link)

An easy read practical explanation of the science behind aquarium keeping and water chemistry. Written by a chemist who is also an aquarist.


You can contact the author of this website by emailing: Albert Sluik.



This website is my little corner of the web where I can indulge my interests of coding websites, breeding challenging tropical fish and taking photographs of said challenging subjects.

It is also a place where I can share knowledge gained.

I am enjoying myself.

That is what this website is all about.