Megalechis thoracata

Hoplo Catfish

Few aquariums are without catfish. In most cases, they live in the bottom layers of water, allowing you to “revive” the lower part of the aquarium. But their main value is that they act as real “orderlies” of the aquarium, eating up the rest of the food left by other fish, and thereby helping to maintain cleanliness in the aquarium. Hoplo Catfish ( Megalechis thoracatais ) one of the most popular decorative catfish. In our article we will consider the main features of the content of these tireless helpers.

Scientific nameMegalechis thoracata
NameHoplo Catfish
Common namesHoplo Catfish, Spotted Hoplo, thoracata
Natural range
widespread in Central and South America
Sizearound 12 cm or 5 inches
Tank size40 L or 10 gallons
Life span8 - 10 years
22-28 C. or 72-82°F
pH 6.0-8.0
GH 5-20
Colormain brown / lighter in young and darker in old
Foodomnivorous fish
Breedingmedium / a bit different than other catfish
Temperamentpeace-loving catfish
around 1 year
Eggsaround 500-1000 eggs / 6 mm size

General information

Hoplo Catfish (Megalechis thoracata) is a freshwater fish from the Callichthyidae catfish family. After the first scientific description made by the French scientist Achilles Valensins in 1840, the fish was assigned to the genus Hoplosternum, but in our time it was moved to the genus Megalechis. The name of the genus can be translated from ancient Greek as “giant snake fish.” Here, the almost cylindrical shape of the Hoplo Catfish body and a considerable size (about 15 cm) were reflected.

Like other armored catfish, the body of the fish is covered with several rows of bone plates. They are necessary to Hoplo Catfish to protect against enemies. Catfish tend to have intestinal breathing: in conditions of lack of oxygen, Hoplo Catfish float to the surface and take a “breath” of air above the surface of the water, which is then absorbed in a special section of the intestine.

Among the main attractive qualities can be distinguished: beautiful appearance, unpretentiousness in content and calm character. This fish can be recommended for both beginners and experienced amateurs.


The body of the Hoplo Catfish is elongated, smooth. The side is covered with two rows of bone plates that converge in the middle of the body. The usual size of the fish is about 12 cm. The head is flattened, powerful. The mouth opening is directed downward. Near the mouth are 2 pairs of sensitive whiskers: the maxillary are directed downward, and the mandibular – forward.

The dorsal fin is small, rounded. The pectoral fins are triangular in mature males and oval in females and juveniles. Distinguish a small adipose fin. The tail is triangular in shape, usually colored dark.

The main body color is brown. In young, it is lighter, in adult fish it gets dark. Small dark spots of irregular shape are scattered throughout the body. The abdomen is almost white. There is an albino form with a milky color and dark spots on the body.

Life expectancy in the aquarium is 8-10 years.


Hoplo Catfish is widespread in Central and South America. It can be found in the basins of the Amazon, Orinoco, Rio Negro, etc.

The biotope characteristic of the Hoplo Catfish is a small freshwater stream or backwater with a weak current, densely overgrown with vegetation. Hoplo Catfish are able to survive a short drought, buried in silt to a depth of 25 cm.

Care and maintenance

Hoplo Catfish are schooling fish, therefore it is necessary to keep them in groups of 3-6 individuals. It is advisable that one catfish has at least 40 liters of water. Must have a cover.

Coarse sand and fine rounded pebbles are suitable as soil. Fish lead a benthic lifestyle and constantly dig in the ground, looking for food. Do not forget to provide a sufficient amount of shelter from stones, natural snags, and grottoes.

Of plants, species with a powerful root system – cryptocorynes, anubias, etc., are best suited. Hoplo Catfish is completely indifferent to greenery. But given their love of constantly digging soil, loose plants will constantly float. It is useful to plant floating species on the surface of the water (Riccia, Water lettuce, etc.) to dim the lighting.

The aquarium must be equipped with a productive filter and compressor because fish love clean and oxygenated water. Be sure to ensure that the fish have constant access to the surface of the water because even in a well-aerated aquarium, Hoplo Catfish will periodically pop up to “take a breath” of atmospheric air. Aquarium lighting should be moderate. Once a week, it is necessary to replace 20% of the water in order to prevent the accumulation of harmful nitrogen compounds.

The optimal water parameters for the content are: T = 22-28, pH = 6.0-8.0, GH = 5-20.


Thoracatums are peace-loving catfish, get along well with the vast majority of decorative aquarium fish. In the natural habitat, the fish prefers twilight, but in the conditions of the aquarium, it is active at any time of the day.

Conflicts with neighbors can occur only if the conditions of detention are violated. If the volume of the aquarium is too small, then adults can pursue representatives of small species. During spawning, aggression rises to the point that the dominant male can kill the remaining males.

Good cohabitants for the Hoplo Catfish will be angelfish, barbs, tetra, Rainbowfish, large live-bearers, small cichlids. It is not recommended to combine with other Demersal fish, for example, bocia – conflicts may arise over the territory. Containing Hoplo Catfish with large predatory species is also not worth it.

Hoplo Catfish ( Megalechis thoracatais )

Hoplo Catfish feeding

Hoplo Catfish are omnivorous fish, in nature preferring various bottom crustaceans, insect larvae, detritus, and plant debris.

It is not recommended to use live or frozen food for feeding, as it is unbalanced and may pose a risk of introducing infections into the aquarium. In conditions of aquarium living, specialized quality dry food for bottom fish is best suited. They take the form of tablets or wafers and immediately sink to the bottom, where they are eaten by catfish. A great choice is the Tetra Tablets TabiMin or Tetra Wafer Mix.

Do not forget that when kept in a common aquarium, catfish eat excellent food residues that other fish did not have time to eat. Therefore, in general aquariums, we recommend using Tetra Selection – these are 4 types of food in one convenient jar: cereals, chips, granules, and wafers.

Tetra FreshDelica treats will help diversify your pets ’diet. These are food organisms (bloodworms, artemia, etc.) in nutritious jelly. They will definitely please your catfish.


The breeding of the Hoplo Catfish is a fascinating process and does not happen like in other catfish. To save eggs, the male builds a nest of bubbles, similar to nests of labyrinth fish (Siamese fighting fish, gourami, etc.). Under suitable conditions, spawning can occur even in a common aquarium, but in this case, roommates can suffer, because the males are very zealously guarding the nest.

It is best to organize a separate spawning aquarium, with a volume of 60 liters or more with sandy soil and small plants. From the equipment, you will need a heater and a low-power filter. The male can be distinguished by the red-orange first ray of pectoral fins. Females have a more rounded abdomen.

A pair of mates landed in a spawning aquarium. To stimulate spawning, it is first necessary to lower the temperature by 1-5 ° C, and then slowly raise it to 25-27 ° C, make frequent changes with soft water (desirable KH = 2). The water level is set at about 15-20 cm. So we simulate the beginning of the rainy season when the fish begin to spawn in nature.

If the conditions for spawning are suitable, the male begins to build a nest. To fix the nest, it is necessary to place a wide sheet of an aquatic plant or a piece of foam in the aquarium. Spawning usually occurs during the day, even before the completion of construction, after which the male collects eggs in the nest, chases the female, and finishes her work. The female must immediately be jailed so that the aggressive male does not score her.

The eggs of the Hoplo Catfish are white-yellow, their number can reach 500-1000 pieces. The incubation lasts about two days, the hatched larvae have a size of about 6 mm. They switch to independent swimming on the second day, hide in dark shelters. After the appearance of the first larvae, the male must be removed from the spawning, as there are known cases of eating offspring by the father. Sometimes a nest with caviar is transferred to another aquarium using a saucer. At the same time, antifungal drugs must be added to the water.

The fry grows quickly (albeit unevenly) and within 2 months after hatching they can reach a size of 2-4 cm. Puberty occurs in 8-14 months.