About the Emerald Catfish
Species Type: Freshwater Fish
Care Level: Easy. Does well in a slightly more narrow range of water parameters and shouldn't be used to cycle an aquarium. Will eat most prepared foods. May have some specific care requirements in terms of particular water parameters, social behaviors, food items etc.
Origin: Upper reaches of the Amazon, Rio Ucayali, Rio Ambiyacu, Rio Tocantins, within the countries of Brazil, Columbia, Peru and Ecuador. Occurs in slow-flowing streams and sluggish waters with dense vegetation.
Compatibility/Temperament: Very peaceful bottom feeding fish well suited to any community of non-aggressive fishes. Must be kept in a small group of at least 3 but will be better in groups of six or more.
This fish is often mistaken for a Corydoras, and it does bear a striking resemblance to C. aeneus. The common names are often misleading, as both fish are regularly seen under the names Green Cory, Green Catfish, Emerald Cory, etc.
The Corydoradinae sub-family contains three genera, Aspidoras, Brochis and Corydoras, all closely related and near-identical in their requirements and behaviours. Some ichthyologists feel the three genera should be combined into one, others suggest two with the three Brochis species included in Corydoras. At present, there are three species recognized in the genus Brochis: B. splendens is the most common, while B. britskii and B. multiradiatus are rarely seen in the hobby.
Brochis splendens grows larger than the very similar Corydoras aeneus, and can easily be differentiated by the deeper body and larger dorsal fin. All Corydoras have 6-8 rays in the dorsal (Burgess) while B. splendens has 10-12. The other two species have 15-18 rays. The dorsal is therefore much closer to the adipose fin on Brochis species.
Does best in a well-planted aquarium with bogwood; it appreciates resting spots under cover of plants or wood. Does not like strong water currents. Brochis will spend more time on the substrate than the average cory.
The dorsal, pectoral and adipose fins are each preceded by a spine which is actually a hardened and modified ray; the pectoral fin spine can be "locked" into position by the fish; care must be taken when netting these fish not to entangle the spines, which can also give the aquarist a nasty jab. They are believed to be a defense adaptation, to lodge the fish in the throat of a predator.
All species in the sub-family will periodically and fairly regularly swim quickly to the surface for a gulp of air. The fish swallows the air and blood vessels in the hind gut extract oxygen from the air; it is then expelled through the vent the next time the fish breaks the surface for another gulp of air. This adaptation is believed to have evolved so that the fish can survive in poorly-oxygenated water such as drying pools during the dry season. It is however essential to the fish's well-being that it regularly swallows air.
This species was originally described as Callichthys splendens by F.L. Castelnau in 1855. In 1872, E.D. Cope named the same fish Brochis coeruleus, and five other names were subsequently assigned to this species. Gosline (1940) suspected the fish were the same species, but it was Nijssen & Isbrucker (1970) who sorted it out, and Brochis splendens (Castelnau 1855) having priority is now the recognized name with B. coeruleus a synonym.
The genus name Brochis is Greek for inkhorn, which the fish resembles; splendens is the Latin "to shine," a reference to the emerald shine reflected under light.
Emerald Catfish Diet
Feeds on worms, insect larvae and small crustaceans in its habitat; readily accepts sinking prepared food such as tablets and pellets, and frozen bloodworms and live worms are relished.
Can attain just over 3 inches.
Minimum Tank Suggestion
20 gallons, preferably long rather than tall.
Ideal water parameters for Emerald Catfish
Soft to moderately hard (hardness to 30 dGH), acidic to basic (pH to 8.0) water, temperature 22-28C/71-82F.