Gouramis - labyrinthine fish worth understanding

I have been breeding gouramis of the genus Trichopodus (formerly Trichogaster, even earlier Colisa) for over 40 years. These are labyrinth fish, which over time have developed an additional respiratory organ, the labyrinth organ, which helps them survive in low-oxygen waters for most of the year.

This group also includes other fish species, such as the genera Betta, Macropodus, Helostoma, Belontia, Parosphromenus and others. Over the years, I have encountered recurring breeding errors that lead to failures and can falsely attribute certain characteristics to these fish. These errors typically include aquariums that are too small, too few fish, water temperatures that are too high, and inappropriate or insufficiently varied feeding, often with completely unsuitable food.

I keep my own gouramis in an aquarium that is 170 cm long, 45 cm high and 50 cm wide, with around 70 to 80 fish from the genera Trichogaster, Trichopodus and Helostoma, and the bottom is tended by Megalechis thoracata.

Territorial behavior

Gouramis are territorial fish. They build bubble nests and defend them against other fish. This behavior, often perceived as aggression, is similar to the behavior of cichlids, which guard their spawning grounds on rocks, in caves, on leaves, or other substrates. In a small aquarium with a high temperature of 26°C or more, the dominant male guards his spawning ground (bubble nest) and drives away other fish. In such cramped spaces, the fish are constantly stressed and insufficiently fed, which ultimately leads to their death, leaving only the strongest individual, which then takes care of the remaining fish, if any.

Natural habitat of gouramis

Allow me a short digression. In 2004, I had the opportunity to participate in a meeting between the regional group IGL Cottbus (International Society for Labyrinth Fish Breeders) and the AKL group (experts in the breeding of labyrinth fish) led by Horst Linke. During this meeting in Naile, I attended a lecture by one of the great breeders of Betta splendens in Thailand, Atis, the owner of Atison's Betta. He presented us with over forty natural breeding sites of Betta splendens. I believe the conditions in which gouramis live are similar. Atis described how the water bodies they live in are seasonal, receding after the rainy season, leaving shallow ponds from which most fish predators, as well as birds and snakes, have disappeared. The remaining water, often only 15 to 40 cm deep, becomes very warm and is filled with rotting plant matter and dead insects, creating ideal conditions for the larvae of mosquitoes of the genus Culex and crustaceans of the genus Cyclops, which in turn feed the fish.

The water in which the fish live and reproduce is low in oxygen. There is more oxygen at the surface than in the water column and at the bottom. It is needed for the development of eggs and also for the hatchlings. The bubbles that make up the nest also contain oxygen, and the secretion they are made of also contains bacteriostatic substances. These protect the eggs from attack by bacteria and fungi. Males naturally defend their eggs with all their might. The aforementioned rotifers and crustacean nauplii serve as the first food.

The fish grow unevenly. I haven't read or heard a scientific explanation for this problem yet. I only believe, like some aquarists, that the reason is the preservation of the species. Faster growing fish are more likely to survive, and in the event of poor feeding conditions, slower growing fish can become food for their siblings or cousins. In the event of a storm that flushes the fish out of the pond into the river, sexually mature fish have a better chance of surviving and reproducing elsewhere.

When the rainy season begins, the ponds reconnect with the streams and rivers, and the fish are flushed to other locations, allowing them to mix and continue to reproduce elsewhere with unrelated fish.

The importance of exchange and cooperation

I would like to mention here that it is cooperation in international organizations that has given me the opportunity to make numerous friends and also to gain knowledge from experienced breeders and often real scientists in the field of ichthyology. The advice I received allowed me to obtain documents that I had dreamed of until now. Isolation only leads to stagnation.

Feeding gouramis

A few more words about feeding. When I started breeding fish, it was common to feed the muscles of warm-blooded animals, such as beef heart, as well as poultry meat. After some time, I completely gave up on this. A cold-blooded animal, in this case a fish, has little chance of digesting this food. A cow has a body temperature of 38°C. The temperature of the water in which we keep fish is much lower. This means that the undigested fats contained in the muscles cause digestive problems and inflammation in the digestive tract of fish. In my fish, this was most often manifested in the spring, when there was a small proportion of plankton in the winter food ration. Over time, I have created a food ration in which 30% to 50% is plankton straight from nature, as it currently occurs in my area, i.e. daphnia, mosquito larvae, and other insect larvae. Of course, I also feed with bloodworms (only in combination with plankton) and artificial food.

I have completely excluded frozen bloodworms (I consider this a crime) from the food ration, as well as frozen red mosquito larvae; I only feed glassworm larvae live in exceptional cases. I will write why. This frozen food is created in such a way that hunters or traders start losing bloodworms or glassworm larvae, so they freeze them and sell them to reduce losses. They freeze dead, rotting and bacteria-infested larvae. They also contain mud, which they have not yet excreted from the digestive tract. This causes inflammatory processes in the body of the fish and the fish die. Treatment usually only ends the suffering of the fish. I don't want to speculate about the reasons.

Breeding gouramis

A few more words about my modest breeding method. I breed fish in tanks with a capacity of about sixty liters. More precisely, with dimensions of 60x40x25 cm. I also read that gouramis need a spacious tank with a capacity of at least 15 liters, as written in one unnamed magazine. Reproduction in such a small space is simply nonsense.

The tank is simply arranged. Sponge filter. I do not use bio-aquacite in the spawning tank. The holes in this medium are large and freshly swimming fish get lost in them and die. Or at least some of them.

Gourami breeding is as follows:

• I put a handful of dry oak leaves into a clean tank (as Horst Linke does).
• I fill it with water and add a small amount of bioflora from Karl Rataj. Sometimes also a small amount of peat extract from Velké Dářko (aquarists in the Highlands call it Rio Negro).
• I set the heater to 26°C - 28°C.
• I place a tile on the surface of the water and usually after two days I put in the spawning pair.
• Female gouramis, if they do not spawn regularly, have a lot of eggs in them and a large part of them may be overripe, unable to be fertilized. If there are not enough fry, I destroy the spawn and after ten days I put the female back in the spawning tank.
• After spawning, I remove the female.
• After 24 hours, the larvae hatch in Trichogaster (Colisa a little later).
• The male takes care of the eggs and larvae.
• Some males don't. I do not know the reason. In my fish, this happens more often with Trichopodus tr.var. Cosby.
• After 24 hours, I add a small piece of dry banana peel to the tank. A small number of protozoa multiply on it. If there are none in the tank, I add them from another tank. I understand that if "neon" aquarists read this, they may be nervous about it, but gouramis benefit from it.
• After the start of free swimming, I start feeding.
• There are many instructions in the literature. But I created my own: I grind high-quality flake food into a mist and feed it every three hours at best. After five days, I give Artemia salina nauplii. I prefer to breed gouramis in spring, when there are enough daphnia nauplii in the fishing grounds.
• You need to go back to very small food when the small fish start to take in air. At this time, they easily choke on larger live or artificial food.
• Fish, even with great care, grow unevenly. I'm not worried about it. You have to learn to feed so that all the fish are sufficiently full.
• I especially cannot recommend sorting fish by size, as older literature advises. It is laborious and does not solve anything. Growth differences persist. Some gourami species experience shock during this manipulation, so the breeder loses a significant number of fish. Trichogaster leerii is particularly sensitive.
• Before any intervention in the aquarium, part of the water in the tank should be replaced with fresh water.
• Currently, many breeding varieties of these fish are bred. Not always to their advantage. Finally, I would like to ask aquarists to use the correct nomenclature of fish. This means using Latin, i.e. scientific, names. And not only for gouramis.

On this occasion, I would like to recall my first lecture. It was held in cooperation with associations from Turnov, Semily and Jilemnice. (They no longer exist today.) My later friend MVDr. František Czefaj gave a lecture there. The question was asked why he doesn't use Czech names for fish. František replied that the only correct ones are Latin, i.e. scientific, names. As an example, he gave: "You all probably know the gourami Colisa lalia (today Trichogaster lalius), what a beautiful fish it is." At that time, breeding mutations did not yet exist. The Czech language invented the name dwarf gourami for this beautiful fish, and the Slovak name “Colisa krpatá” crowned it. As if it were some kind of degenerate fish.

Finally, I would like to wish all breeders a lot of joy in breeding aquarium fish. If you give gouramis enough space and high-quality food, you can enjoy their beauty for many years. My Trichopodus usually live for over 8 years, Trichogaster a little shorter, and Helostoma even over 20 years.

Photos in order:

• Trichogaster fasiatus, male
• Trichogaster labiosus, orange male
• Trichogaster sumatranus, male
• Trichogaster sumatranus, color change
• Fry on the first day
• Nest with eggs
• Trichopodus cosby, male
• Spawning of golden gouramis
• Trichopodus - silver form, female
• Cosby spawning in my water
• Golden form fed with cyclops
• Community aquarium