Dwarf Gourami Fact Sheet
The scientific name usually used for the Dwarf Gourami is Colisa lalia. For more details about this, see the section: “Scientific Names” at the end of this article. The Dwarf Gourami is native to India, Bangladesh and Pakistan, and possibly to Myanmar, Nepal and Borneo. It is found in the tributaries of the Ganges and Brahmaputra rivers, and is found in slow moving streams and lakes, and can grow in flooded rice fields. It has been introduced to Colombia, Singapore, Taiwan and Florida in the United States of America. It is probably established in these countries. It has also been introduced to The Philippines and Canada, but I do not know if it is established in these two countries.
As its name suggests this is one of the smaller gouramis. Although 10 centimetres (4 inches) is reported as a maximum size for this fish, most of the ones I see are more like 5 centimetres (2 inches) long.
The normally recommended temperature range for this fish is 25 – 28 degrees C (77-83 degrees F).
The Dwarf Gourami comes from the tropics, and is basically a tropical fish. However, part of its range includes waterways in the mountainous areas of India, and it has been reported in Nepal which is not a hot country. The places it has been introduced to are mainly tropical, but it is surviving in the wild in Florida where it has apparently escaped from fish farms. The climate of Florida is not tropical although it certainly does not get as cold as most of the United States.
Dwarf Gouramis have been bred outside in Germany (In the summer). A single specimen survived in a garden pond in the Adelaide Hills town of Mount Barker right through the winter. These observations suggest that at least some Dwarf Gouramis have better cold tolerance than is generally recognised.
A pH of between 6.0 and 7.5; with a hardness of no more than about 19 dH is suitable for maintaining the adults.
The Dwarf Gourami seems to be particularly susceptible to nitrites. A good filter should be used to prevent the build up of nitrites, and the general level of cleanliness should be high. However, this fish comes from sluggish waterways and should not have turbulence in all parts of the tank.
The Dwarf Gourami comes from water with a lot of plants, so it should be kept in well planted aquariums.
Dwarf Gouramis are omnivores, and they are easy to feed with normal fish foods. These should be supplemented with live or frozen foods like Blood worms or Daphnia.
The Dwarf Gourami is one of the types of fish that is capable of shooting water droplets at insects above the water and knocking them into the water.
The Dwarf Gourami is a labyrinth fish and can breathe air as well as water. This allows them to survive in still water which can be low in Oxygen. My own observations suggest that this fish cannot get all its Oxygen requirements from the air, and does need some dissolved Oxygen in the water.
The Dwarf Gourami is a peaceful fish and can be kept with most of the tetras and similar fish. I would avoid the smallest tetras like the Neon Tetra, and also any fin nipping fish.
I would not recommend it as a companion for any of the other Gouramis, nor for Siamese fighting fish or Paradise fish. I would also not put them with any of the livebearers like Guppies, and also not with Australian native fish like the Murray Cod. The reason for the exclusions in this paragraph is to reduce the possibility of transmission of Dwarf Gourami Iridovirus.
The male Dwarf Gouramis of all the colour variations are brightly coloured, while the females of most colour variations are relatively drab in appearance. However, the Coral Blue Dwarf Gourami is an exception to this in that the Female is also a beautiful Coral Blue colour and is scarcely inferior in colour to the male. The one thing common to all the colour variations is that the males all have some red on them while the females have almost no red.
It is extremely unlikely that the dwarf Gouramis will succeed in breeding and raising babies with other fish in the tank. So you need to set up a tank specifically for their breeding. Some people have succeeded with tanks as small as 20 Litres (5 US Gallons), but I prefer a tank of at least 50 litres (13 US gallons).
The temperature should be about 27 degrees C (81 degrees F), and the pH neutral or slightly acidic. The hardness should be no higher than 10 dH. Normally the water level is lowered to about 20 centimetres (8 inches). Although I certainly recommend doing this, I have also succeeded in breeding this fish with much deeper water.
The breeding tank should be very well planted with a variety of types of plant, and including some floating ones.
You should only have one male present, but he can handle more than one female.
The Dwarf Gourami is a bubble nest builder. Unlike most of the Gouramis, the male usually incorporates some floating plants into their nest. As well as actual whole floating plants he may also incorporate bits of plants that he has broken off and chewed. The nest is relatively large compared with the size of the fish as well as being more elaborate than that of most gouramis.
The male will entice a female under the nest. They may have a few trial matings. The male wraps his body round the female, turning her on her side or upside down and he releases his sperm at the same time as she releases her eggs. Any eggs that do not float up into the nest the male will pick up with his mouth and put into the nest. One female can lay up to 800 eggs.
After spawning with one female, the male will entice another one under the nest and this can continue until he runs out of females ready to breed. The total spawning procedure can take several hours. After spawning the male will add another layer of bubbles to the underside of the nest. He will defend his nest and the eggs. The females will need to be removed without disrupting the nest.
Raising the Fry
The eggs should hatch in 12-24 hours, and the fry should be free swimming in about 3 days. It is safer for the male to be removed once the fry are free swimming.
Dwarf Gourami fry are very small. Some people cannot even see them with the naked eye, so babies will need microscopic food for some time. Often the first food to be given to them is green water. This is water with so much free-swimming algae that it looks green. The babies will grow and be able to eat bigger microscopic food, generally referred to as infusoria. After a while they will be able to graduate to bigger food like newly hatched brine shrimp and screened Daphnia.
Live food is best for the babies, but this can be supplemented with commercial fry foods.
A filter is necessary, but a normal power filter would suck up many of the babies. People have different ways of solving this problem. Some people put a thin cloth over the water inlet of the filter to stop the fry being sucked in. My preferred solution is to use a sponge filter.
In the wild the Dwarf Gourami provides some food for the local people. It is quite common over a large area of its natural habitat. Indications are that it is not in danger of extinction in the near future. However, the increasing development of the areas it is native to as well as the rising sea level that could threaten the lower lying areas of its range could be a long-term threat.
Over forty years ago I first kept and bred Dwarf Gouramis. At that time they could reasonably be described as a hardy fish. Unfortunately the ones we get nowadays have lost much of this hardiness. This loss of hardiness seems to have been caused be several different things.
They have been selectively bred, producing a number of different colour variations. It is likely that many of these are inbred, and suffer from the lack of vigour frequently caused by inbreeding.
Most of the Dwarf Gouramis bred in places like Singapore will have been kept in controlled conditions and individuals which would have died out quickly in the wild will have survived and often been used for breeding. Related to this is that in captivity fast growth would have been selected for, and particularly fast growth under the near forcing diets fed to commercially bred fish. The fast growing fish are often not as hardy as wild ones.
Related to the lack of hardiness in many commercially bred Dwarf gouramis is the fact that many of them are diseased. They are susceptible to the normal aquarium fish diseases, but one is of particular concern. This is the
Dwarf Gourami Iridovirus.
This disease kills the Dwarf Gouramis slowly, sometimes taking as long as a year to kill them. The symptoms include wasting of the fish and there is little doubt that before this disease was identified, fish tuberculosis was blamed for some of the deaths from this virus. This virus may have become a problem because of the extensive inbreeding of this fish in Singapore.
Many virus diseases are specific to a single species, and it is frequently reported that only Dwarf Gouramis can get the Dwarf Gourami Iridovirus. However there are also many conflicting reports.
One study by a team led by Professor Richard Whittington of the University of Sydney, Australia found a 99.95% genetic similarity between the Dwarf Gourami Iridovirus and a virus outbreak in 2003 that killed farmed Murray Cod, Maccullochella peelii peelii. A test showed that Murray Cod can be infected with the Dwarf Gourami Iridovirus, and had 90% mortality.
There is fear that the Mosquito fish (Gambusia species) can act as a carrier for this virus and aid its spread through wild fish populations. This virus has also been reported as affecting swordtails.
One of the problems with these reports is that there are many types of fish Iridoviruses. Some of them will kill or make the fish ill while others seem to have no bad effects on the fish. To really find out what is happening would take a major research effort.
Several internet articles say that 22% of Dwarf Gouramis coming out of Singapore have this virus. This figure is actually based on an study of Dwarf Gouramis in Australian retail aquarium shops. The study found that 22% of these fish were infected with this virus. All the tested fish had been imported from Singapore. The fairly reasonable jump was made to state that 22% of the Dwarf Gouramis coming out of Singapore were infected.
Of course all the tested fish would have been through quarantine and any fish showing signs of disease would have been destroyed. If any batch of fish had a lot of diseased specimens the whole batch would have been destroyed. If an importer loses a whole batch of fish he has lost a lot of money and would look for another supplier.
At least one normally reputable internet site says that most of the fish coming out of Singapore are infected. 22% is a very worrying figure, but it certainly is not “most”.
Government Action Needed Now!
The trade in ornamental fish is a major part of Singapore’s trade. If there is a problem this serious with Singapore’s fish, it needs to be fixed.
Some years ago, a large ornamental fish farm in Australia had a serious problem with a fish disease. With government help they systematically eradicated the disease. This fish farm now has an extremely good reputation for the quality of their fish. Unfortunately they do not breed Dwarf Gouramis.
The government of Singapore needs to recognise that there is a serious problem and to solve it before Singapore’s export trade in fish is ruined.
In English, the Dwarf Gourami is called by many different names, including ones that cause considerable confusion between the species and similar ones. Some of the other English names used for the “Dwarf Gourami” are: “Dwarf Gouramy”, “Red Lalia” and “Sunset Gourami”.
In French it is called “Le Gourami nain”
According to Fishbase, the accepted name is “Colisa lalia”, (Hamilton, 1822) but in 2009 there was a proposed revision of names, changing the name of the genus Colisa to Trichogaster. This would make the correct name “Trichogaster lalia”. Other names that have been used include: “Trichogaster lalius” (Hamilton, 1822), “Trichopodus lalius” (Hamilton, 1822), “Trichopodus lalius”, (Hamilton, 1822), “Polyacanthus lalius” (Hamilton, 1822), and “Colisa unicolor” (Cuvier, 1831).