The first aquarium for the majority of new fishkeepers is a community aquarium containing small, peaceful tropical fish. The range of ideal community species (which tend to occupy the middle waters of an aquarium) is enormous; it includes South American tetras as well as Southeast Asian danios, rasboras and the (generally) peaceful smaller barbs.
These species will do well in near neutral, moderately soft water (pH 6.5 to 7.5, DH 4 to 8) maintained at about 76 degrees Fahrenheit. One common factor among these types of fish is that they only do well when kept in shoals of six or more.
Today’s fish hobbyists realize that catfish are not there just as the clean-up crew to consume whatever uneaten fish food ends up on the substrate. Like all fish, catfish have specific requirements that relate to water chemistry, decor and dietary needs. The old-fashioned habit of keeping just one or two small catfish per aquarium is also fading as we learn that most small catfish species are shoaling fish in their natural habitats.
There is a large selection of catfish available these days at most good local fish stores — and some of these them have special requirements that are not immediately apparent. These and other aspects will be explained as we take a look at the small catfish available for a community aquarium.
In the wild, Corydoras are bottom-dwelling, shoaling fish that are usually diurnal, needing driftwood to rest under at night. These fish do much better when kept in shoal of six or more, allowing them to socialize and interact.
Corydoras are omnivorous, feeding on sinking pellets and wafers, as well as flake foods. Frozen bloodworms and other meaty foods are also taken. Their diet should also include some plant material, such as algae wafers, but they will not clear up algae from the aquarium glass. Smooth gravel is recommended to prevent damage to their barbels.
Today’s market of small catfish is still dominated by Corydoras, with more than 200 species found in the wild. The skunk cory (Corydoras arcuatus) is a nice example of a handsome cory that comes from the Amazon River basin. It is a smaller cory, growing to about 2 inches. It has a stocky body that is pinkish-beige with a touch of gold, and a long, black stripe running from the mouth through the eye and then along the dorsal ridge into the base of the tail fin on each side of the body. All the fins, including the adipose fin, are also tinged in pink. The mouth has two pairs of barbels on the upper jaw. The skunk cory has two rows of overlapping bony plates on each side just under the skin, while dorsal and pectoral fins have strong spines that add to the fish’s defenses.
In typical Corydoras behavior, this species comes to the surface to gulp air, which is stored in a part of the intestine modified for air breathing. Another interesting cory habit is that they blink their eyes.
African Glass Catfish
The three-striped African glass catfish (Pareutropius buffei), also known as the Debauwi cat, belongs to the Schilbeidae family. They are found in the West African river systems of Benin, Nigeria and Cameroon. This catfish grows to 3 inches and has a silvery gray, laterally compressed, elongated body with a shiny silver belly. A bold black stripe runs along the midline from the eye into the base of the tail fin and a parallel narrower, shorter stripe runs above both the belly and a third narrow adjoining stripe above the long semi-transparent anal fin. Black patches adorn each lobe of the forked tail fin, both of which are also semi-transparent. This catfish also has a small adipose fin. The three pairs of small barbels around its mouth can be difficult to see. In spite of being called a glass catfish, the body of this attractive species is not transparent, hence its bones and insides are not visible.
Debauwi cats are shoaling fish that usually swim near the substrate and in mid water in a head-up position. They can be nervous fish if just one or two are kept, but they are sociable when maintained in a shoal of six or more. They need a lot of swimming room and like large plants under which they can congregate when resting. They also prefer dimmer illumination, easily provided by floating plants, which encourage them to be active during the day. They prefer water currents that allow them to hang in the water by simply moving their tail fins.
They will accept most fish food, including good-quality flakes, but are rather keen on small live foods, such as Daphnia and mosquito larvae, as well as frozen bloodworms and brine shrimp. Under such conditions, these catfish prove to be quite hardy and easy-to-care-for.
The upside-down catfish (Synodontis nigriventris), belonging to the Mochokidae family, comes from the River Congo drainage in Central Africa. This catfish grows to about 4 inches and starts life swimming in the normal position before adopting the characteristic upside-down orientation at about 2 months of age. Its barrel-shaped body tapers toward the forked tail fin and is flattened along the belly. The pale brown, scaleless body is covered in darker patches, while the belly is also dark in color. The dorsal, pectoral (with a thickened spine) and tail fins all carry brown stripes or patches, as does the large adipose fin. The mouth — located at the top of the catfish because of its upside-down position — has three pairs of barbels. In the wild, these mainly nocturnal catfish (with large eyes) often feed on insects at the water surface, though they also graze on algae on lower surfaces.
Upside-down catfish utilize the mid to upper waters of the aquarium. They do best when maintained in groups of four or more. They like to rest under overhanging driftwood, rocks or even large broad-leaved plants, all of which allow them to maintain their upside-down position. These catfish are peaceful and make good tankmates for the tetras, small barbs and rasboras noted earlier; they can also be kept with some of the larger African tetras, such as the regular Congo tetra (Phenacogrammus interruptus) or even the yellow Congo tetra (Hemigrammopetersius caudalis). Although they are largely nocturnal in the wild, upside down catfish are often up and about in the aquarium during the day. In an aquarium, these catfish will readily take all types of foods, but their diet should include some live or frozen foods.
Glass catfish (Kryptopterus minor), also known as Asian glass catfish and phantom catfish, come from slow-moving waters of the Indonesian part of Borneo. Growing to just 3 inches, these are truly “glass” fish, with an elongated, laterally compressed body that is (for the most part) translucent. The bony spine, swim bladder and other internal organs are clearly visible. The internal organs, which occupy a surprisingly small amount of space, are enclosed in a silvery sac behind the head.
Two thin black lateral stripes run on each side of the spine from the head to the base of the tail fin. The dorsal fin consists of a single spine and is usually in the down position and thus not visible. The transparent anal fin is long, running from below the pectoral fins to the tail fin base. The forked tail fin is also transparent. The glass cat has a single set of long barbels above the mouth. This species may be colorless, but the tiny scales on its glassy body can catch the light, reflecting a yellow tinge that shifts in hue and is rather attractive.
These glass catfish are naturally shoaling fish that don’t do well when kept as one or two individuals. Conversely, they do quite well when kept in groups of six or more, and tend to lose their nervousness as a result. They are generally midwater swimmers that like to shimmy in water currents in a shoal with their heads up, often changing positions, with one from the back coming to the front. They also like to hang out under large-leaved plants or overhanging driftwood when resting.
Glass catfish are not particularly fond of flake food. They will, however, become accustomed to taking flakes in mid water — but not from the substrate. They are particularly fond of live food, such as mosquito larvae, Daphnia and brine shrimp, as well as frozen foods, such as bloodworm and brine shrimp.
The two-spot catfish (Mystus bimaculatus) belongs to the Bagridae family and is found in some peat swamps on the large island of Sumatra, where the water is fairly soft and acidic (pH 4.0 to 5.5). Growing to about 3 inches, this catfish has an elongate and somewhat compressed body that is pinkish-brown in color. It has a dark spot behind each gill just below the dorsal fin and a black stripe usually edged in white on the base of the tail fin. A thin red stripe runs between the gill and tail markings. All the fins are clear, including the forked tail fin and well-developed long adipose fin. The leading ray of the dorsal and pectoral fins is in fact a stout spine that protects the catfish from predators. Like other bagrids, the two-spot catfish has scaleless skin and four pairs of prominent barbels around its mouth. The silver-rimmed eyes stand out on this fish.
These catfishes are shoalers that engage in a lot of interaction among members of a group. They should not be kept solitarily; try to keep six or more together. They are active swimmers, whether in mid water or scavenging for food along the substrate. Although they live in soft, acidic water in the wild, they adapt well to water that is neutral and even with some hardness (which benefits from the addition of some peat).
These catfishes do well in planted tanks that have driftwood arranged to create come caves in which the fish can rest. They take all kinds of fish food, including flake, which will be consumed in mid water or after they go to rest on the aquarium bottom. However, they should be offered some live or frozen food at least once a week. Two-spot catfish rarely bother other fish in the aquarium.
Queen Arabesque Pleco
The Queen Arabesque pleco (Hypancistrus sp. L260) is a scientifically undescribed species belonging to the Loricariidae family. It comes from the Rio Tapajos basin of the Amazon and has been available to fish hobbyists since 1998. This pleco, which grows to 31/2 inches, has a large flat head, tapered body and flat belly. The suction-cup-shaped mouth is fitted with small teeth and one pair of barbels, and is located on the underside of the head.
These catfish have longitudinal rows of bony plates called scutes over the upper parts of the head and body. Strong pectoral and dorsal fin spines offer additional protection. The dark brown body of this catfish has thin, white, irregular vertical stripes from the head to the base of the tail, which extend into all the brown fins where they might break up into spots. Mature males, which are slightly larger than females, have larger odontode (toothlike) spines on the pectoral fins and cheeks.
Each Queen Arabesque pleco (these are bottom-dwelling fish) likes to have a small cave to itself where it can hang out during the day, coming out at dusk. Caves can be made from four small pieces of slate glued together. If space is limited, males tend to squabble. With a group of six, two males to four females is a good ratio, but because these plecos can be expensive, a trio of one male and two females is an alternative.
These plecos are carnivores; they will do badly if fed a diet of just algae wafers. They eagerly take live and frozen foods — but only from the substrate. These include bloodworms, brine shrimp and other meaty preparations, and they will also feed on sinking food tablets or flakes that reach the bottom. Good water quality is essential for the well being of these plecos.
Our survey of diverse species of small catfish suitable for a modest size community aquarium has taken us across the continents of South America, Africa and Asia. The common feature of the selected small catfish species is that they are all social animals that do best when kept in groups of six or more.
All the catfishes discussed here need a varied diet that includes more than just plant protein, with live or frozen foods necessary at least once a week. All catfish need excellent water quality, which requires a good filtration unit and regular water changes to remove nitrates. The filter will also supply any water current that the catfish need. All of these catfish like to spend their rest periods out of sight, be it in caves or under large-leaved plants.
Apart from the two-spot catfish, these species may not be the most colorful of fish, yet they do have a subtle beauty. The habits of catfish habits are also different from those of tetras, barbs and danios, adding to the overall interest of maintaining a healthy community aquarium.