''Megalechis thoracata'' (black marble hoplo, spotted hoplo) is a species of

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

of the family

Callichthyidae Callichthyidae is a family of catfishes ( order Siluriformes), called armored catfishes due to the two rows of bony plates (or scutes) along the lengths of their bodies. It contains some of the most popular freshwater aquarium fish, such as many ...

. ''M. thoracata'' is found east of the Andes in the Amazon, Orinoco, and upper

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

basins, as well as in the coastal rivers of the

Guianas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * ...

and northern Brazil. Recent introductions were recorded in the upper

Paraná River The Paraná River ( es, Río Paraná, links=no , pt, Rio Paraná, gn, Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Br ...

drainage.

Care in captivity

Overview: The Spotted Hoplo Catfish is an incredibly hardy and relatively easy species to keep in captivity, with the main difficulty being the maximum size of around 6 inches, or 15 cm.They are a very peaceful fish, with the only exception being when the males are guarding a

bubble nest Bubble nests, also called foam nests, are created by some fish and frog species as floating masses of bubbles blown with an oral secretion, saliva bubbles, and occasionally aquatic plants. Fish that build and guard bubble nests are known as aph ...

at breeding time. They can be kept with almost all tankmates, but they will likely eat anything that can fit in their mouths. This rule also applies for larger fish, as the Hoplo may get eaten or have its barbels or fins damaged by large, potentially aggressive fish, such as South American Cichlids, African Cichlids, larger catfish and basically anything that can fit the Hoplo in its mouth or shows aggression. Tank Setup: They need a soft sand substrate, as they are bottom dwellers that spend lots of time digging around for food. The soft sand is essential, as other coarse grained or abrasive substrates can irritate the fish's sensitive

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some ...

, and even cause them to fall off. To thrive in the aquarium, they need a minimum tank size of 55 US liquid gallons, but as a rule of thumb for this fish, the larger the tank, the better. They also like to live in groups of at least five, but still do fine alone or in pairs. Hoplo Catfish need hiding places, usually in the form of rocks, wood and platns, such as variations of

Anubias ''Anubias'' is a genus of aquatic and semi-aquatic flowering plants in the family Araceae, native to tropical central and western Africa. They primarily grow in rivers and streams, but can also be found in marshes. They are characterized by broad ...

, valisineria,

java fern ''Leptochilus pteropus'', synonym ''Microsorum pteropus'', commonly known as Java fern after the Indonesian island of Java, can be found in Malaysia, Thailand, Northeast India and some regions of China. It is a highly variable plant with several ...

and

micranthemum ''Micranthemum'' is a genus of flowering plants belonging to the family Linderniaceae. Its native range is Eastern USA to Tropical and Subtropical America. Species Species: *'' Micranthemum arenarioides'' *'' Micranthemum bryoides'' *'' Micra ...

. Floating plants are also appreciated, as they provide extra cover. Water Conditions: Despite the Hoplo being a very hardy fish, like all fish they need a mature, cycled tank with the correct parameters for almost all hardy tropical fish. As they are a

tropical fish Tropical fish are generally those fish found in aquatic tropical environments around the world. Fishkeepers often keep tropical fish in freshwater and saltwater aquariums. The term "tropical fish" is not a taxonomic group, but rather is a gene ...

, the optimal temperature for them is around 24-28 degrees Celsius, but they can adapt to temperatures in the 22-30 degrees Celsius range, which is not recommended.

Habitat

The natural habitat of Megalechis thoracata is slow flowing, low oxygen parts of the Amazon, Orinoco, and upper

basins. For this reason,

of the family

among other fish, have developed a unique way of breathing, where the fish will take a gulp of air at the surface of the water. The oxygen will then be absorbed through the lining of the stomach and intestine. This is known as gastrointestinal respiration. They will feed on small to medium-sized worms and other invertebrates, small fish, and general detritus.

Ecology

''M. thoracata'' has been observed to produce sounds during territorial behavior in males at their nest sites and especially during spawning, and during aggressive behavior in both sexes. ''M. thoracata'' males aggressively defend territories against intruders.

References

* {{Taxonbar, from=Q1573248 thoracata Fish of Bolivia Freshwater fish of Brazil Freshwater fish of Colombia Freshwater fish of Ecuador Freshwater fish of Peru Fish of the Amazon basin Taxa named by Achille Valenciennes Fish described in 1840