Emerald Catfish (Brochis splendens)

Common Name:

Emerald Catfish.

Scientific Name:

Brochis splendens.

Family:

Callichthyidae.

Sub-Family:

Corydoradinae.

Distribution:

Brazil, Ecuador and Peru (especially the large tributaries of the Amazon thereof and the Amazon proper in Brazil).

Size:

Approx 3 inches for males and 5 inches for females.

Diet:

In the wild, these are often seen feeding upon insect larvae, worms, small crustaceans, and whatever else inhabits the vegetation that lines the banks of their riverine homes. In the aquarium, this translates to a lot of livefoods, especially tubificids and chironomids (bloodworms). Sinking "bottom-dweller" pellets which are recommended for cories can also be of use here, as can shrimp pellets. I have not had much luck delivering freeze-dried tubificids to bottom-dwelling cories because of their proclivity to float rather than sink (and the inability to satisfactorily force them to adhere to the side surface of the tank), so I would not recommend them for Brochissp. cats either.
Two aspects of feeding should be stressed: the relative ability of worms to escape prior to being noticed by their intended piscine predators and the fact that B. splendens, like the rest of its corydoradine counterparts, ascertains the presence of food from sensing it with its barbels. Thus, food dropped in front of a hungry emerald cat may be ignored until the cat follows a circuitous route back to the food in front of its face.

Water Temperature:

They need a slightly acidic pH (somewhere close to 6-6.5) and a maximum of 10 dGH hardness. They do best on soft, fine substrates but, as noted in AquariumFish Magazine, their live foods may easily escape in such a venue, so leaving a small patch of tank floor exposed is optimal. This feeding arena will be, by operant conditioning, quickly recognized by such by the emerald cats. A heavily planted tank is a must for these fish to feel secure and floating plants are the choice venues for egg deposition, so those, too, are optimal for a B.splendens tank.

Life Span:

10+ Years.

Description:

Larger than your standard cory and more rotund, these callichthyid/corydoradine cats can achieve a size of 3" for the males and 4-5" for the females. They are generally an emerald green (thus the common name). The former commonly-used specific name of these fish belies the bluish tint which the juveniles may present. At one point, juvenile B. splendens were actually classified under a different name from their parents, but noticing the metamorphosis in color during the maturation process caused early keepers of this fish to realize that one of the two scientific names needed to be relegated to junior synonomy.

They have the face of a corydoradine fish, and, for all practical purposes, look like an obese version of their smaller cousins. These are often sold as Emerald Aeneus Cories or Emerald Green Cories because of these superficial similarities, but, when looking at the dorsal fin, experienced cory keepers will notice that it seems much more elongated than that of their charges. The dorsal fin of the Brochis sp. cats also have more rays than those of the cories.

Species Behavior

These are shy, peaceful schooling fish which need a large quantity of conspecifics in order to feel secure in their tanks. They get along well with most fish that are not aggressive and not gluttonous. Other than the shyness, in a well-planted tank, they will behave like their cousins in the genus Corydoras and, as the experienced cory keeper would tell you, many a fun time is in store for even the casual observer. They do have a tendency to prefer a tank with floating plants so, if it is at all possible to give them such cover, it would be a good idea to do so.

Sexing:

As mentioned in the species description, males are smaller than females. The latter sex also has a tendency to become more rotund during the spawning season. The ventral surfaces may also differ in colour -- the females will have pinker bellies and the males will have yellowish ones.

Breeding:

Like many of the Corydoradines, these can be difficult to induce to breed for their first spawn but may do so regularly thereafter. Spawning is often related to changes in weather, which, in the wild, would signal the start of the rainy season. Thorough water changes in conjunction with barometric pressure drops may be all that is needed as breeding stimuli. Floating plants are heavily favored for egg deposition, so a spawning tank should have some of these.
Unfortunately, B. splendens is harder to raise from eggs than many of the corydoradines as a lot of eggs fungus during the incubation period. The addition of methylene blue or a similar antifungal to an incubatory tank may be necessary to inhibit the growth of Saprolegnia and possibly enhance the chance of survival for the Brochisfry.
The infamous T-position is assumed by these fish during fertilization and, using her fins as if they were hands, the female deposits a dozen-plus eggs at a time throughout the tank. The parents do not eat eggs if they are well-fed but overfeeding parents can serve as an obstacle to fungal retardation. It may be best to remove the floating plants to an incubatory tank at the conclusion of the spawning ritual.
Since the fry are so tiny, they may take infusoria, extremely little bits of tubificids or powder-sized livefoods. I do not know at this time if the foods developed for the fry of egglayers are sufficient for the survival ofB. splendens fry but that may be an experiment which I am willing to undertake should I get a prolific pair.

Natural Conditions:

These fish prefer sluggish waters within the Amazonian watershed, especially those whose banks are filled with plants. Like other corydoradines, they can rely on their air-breathing and survive the annual drying of the river system in South America, so they have been found in muddy puddles during the dry season. This, however, is a less-than-desirable way to permanently care for them in an aquarium setting.

Tank levels:

Bottom Strata.

Housing:

20 gallons is the absolute minimum for a small group.

Miscellaneous:

This fish, first classified by Castelnau in 1855, has found several generic and specific umbrellas to call its own before its eventual classification as B. splendens Castelnau actually dually classified it in 1855 as both Callichthys splendens and later in that year he called a different morph of the same fish C. taiosh. Cope then took four stabs at naming different morphs, three in 1872 (Brochis dipterus,Brochis coeruleus -- the name which reflected the bluish tint that some juveniles may exhibit, and Corydoras scutatus) and Chaenothorax bicarinatus in 1878. Ellis, in 1913, gave the fish yet another name: Chaenothorax eigenmanni. Actually, there is little interest in these names, save for two. First of all, Cope considered the fish to be a Corydoras with his C. scutatus designation. Many others have since attempted to apply the common name "Cory" to this fish. The other name of interest is B. coeruleus. This was applied to the fish for a long time, but it is rarely found in modern aquarium literature. There is a lot of usage in antiquated literature, though, so drawing attention to it is necessary. This fish is often seen as a so-called "contaminant" in shipments of C. aeneus (hence the oft-used "Emerald Green Aeneus Cory" in many shops). The similarity in appearance is easily overlooked when the dorsal fin is carefully examined. While possible to collect these as contaminants, it is probably best to purchase a shoal at once if at all possible.