Emerald catfish

Geographic Origin and Biotope: Amazon basin (Brazil, Peru, Ecuador, Colombia). Very adaptable, inhabits main rivers but moves into swamps, meanders and oxygen-poor temporary lagoons.

Taxonomy and Morphology: Emerald Corydoras. Formerly known as Brochis splendens, then Corydoras, now under revision. Massive build, a "tank" compared to classic Corydoras. Differs from Corydoras by having 10-12 rays in the dorsal fin (versus 7).

Social Behavior: Gregarious, good-natured. Continuously sifts the bottom in groups of at least 5-6 units. Rests on wood and makes lightning dashes to the surface to swallow atmospheric air (accessory intestinal respiration).

Coloration and Sexual Dimorphism: Fantastic emerald-green or metallic bronze-iridescent coloration on the armored back, pinkish/white belly. Females are noticeably more voluminous and wider, while males have a flat belly.

Aquarium Setup: Tank from 100 cm (40 inches) up due to the size. Very fine sand bottom mandatory to protect the barbels (sharp gravel causes lethal infections). Dens and roots to provide shady cover.

Diet and Feeding: Omnivorous bottom fish, it is NOT a feces eater or "scavenger". Feed with sinking tablets for bottom fish, frozen bloodworms, tubifex and granules. Voraciously stirs the sand.

Water Quality: Hardy, withstands pH or hardness fluctuations better than other Amazonian fish (pH 6.0-7.5, GH 2-15), but bottom hygiene must be maniacal: accumulations of putrefying bacteria in the sand consume their barbels.

Compatibility and Tankmates: Excellent community fish for medium/large Amazonian tanks. Ideal with Discus, Angelfish, large Characins and Dwarf Cichlids. The size prevents it from being bullied by mid-tank fish.

Aquarium Reproduction: Possible but requires well-fed specimens and stimuli such as temperature drops (cold water) to simulate Amazonian rains. The eggs (about 100-200) are stuck to the glass or broad leaves. They do not eat eggs and offspring.

Risks and Diseases: Suffers from erosion and fungal infection of the mouth barbels due to sharp substrates (stones) or poor siphoning. The hard rays (spines) of the dorsal and pectoral fins possess a weak venom gland: handle with care during transport.