South America is a hotspot of catfish diversity. There are at least 700 species within the family Loricariidae (plecos) alone. Ecological diversity is high, too. There are South American catfish in streams, rivers, lakes and swamps. Quite a few live in estuaries, and a few inhabit the sea. There are even species that favor caves and waterlogged leaf litter. Most are opportunists, but some are top predators, while others consume wood, algae, fruit — even blood.
Fortunately for ambitious aquarists, South American catfish can do well in captivity. Optimal catfish conditions are soft, slightly acidic water (2 to 12 degrees dH and pH from 6 to 7.5) at a temperature from 72 to 79 degrees Fahrenheit. Feeding isn’t much of a problem either — just provide a good mix of fresh, frozen and pellet foods.
The fish we call “shovelnose cats” are large catfish characterized by a long, dorsoventrally flattened snout that may account for a third of their length. They are members of the Pimelodidae family, the same group that includes the spotted pimelodus (Pimelodus pictus) and the red-tailed catfish (Phractocephalus hemioliopterus).
Even the smallest shovelnose is a big fish by aquarium standards. Sorubim lima is by far the most easily maintained shovelnose, but it grows to about 18 inches in length. The beautiful zebra shovelnose (Brachyplatystoma tigrinum) gets to 24 inches or so, and the tiger shovelnose (Pseudoplatystoma fasciatum) is even bigger, growing up to 3 feet in aquaria and likely larger in the wild. But that isn’t the biggest shovelnose by any means — the biggest is Brachyplatystoma filamentosum, a leviathan capable of reaching more than 9 feet in length. It is surely one of the most powerful freshwater predators on Earth.
Sorubim species are fairly small and can make excellent aquarium residents. The most widely traded is Sorubim lima, and this species does well in tanks 200 gallons and larger. It is an easygoing fish that may be kept with peaceful fish of similar size, including plecos, oscars and characins like Myleus rubripinnis. It may be kept singly, but it does best in small groups.
While newly imported Sorubim lima prefer live foods like earthworms and river shrimp, they are easily weaned onto items like tilapia fillets and cockles. Prawns and mussels are rich in thiaminase, a substance that breaks down vitamin B1, but they work well as occasional treats and should not be fed often. Once settled, Sorubim lima will take catfish pellets. Adults only need to be fed three to four times a week. Note that live feeder fish are not required and in fact pose a variety of health risks. Feeder fish should not be used at all, even for newly imported specimens.
The ornate pimelodus (Pimelodus ornatus) belongs to the same family as Sorubim lima (the family Pimelodidae). It is a beautiful species with distinctive stripes: a vertical one behind the pectoral fins and two horizontal stripes along either flank. Although it gets quite large (around 10 to 12 inches), it isn’t so large that it’s difficult to house. Ornate pimelodus grow astonishingly quickly, though, and a specimen can grow to 8 to 10 inches long by its first birthday.
Overall this species is undemanding, provided that it can be adequately housed. Perhaps surprising for a big catfish, this species naturally lives in groups, and while single fish do all right, this species really shines when kept in groups of three or more specimens. If nothing else, the extra security a school provides will encourage these shy nocturnal predators to swim about during the day. A trio will need an aquarium upwards of 100 gallons in size, and the more space, the better.
Though predatory, ornate pimelodus are not aggressive and get along well with tankmates of similar size. They are not fussy about food and will eat just about anything from sinking pellets and frozen krill to earthworms and slivers of tilapia fillet.
Whiptail and Twig Catfish
Whiptails and twig catfish are closely related groups within the Loricariidae family, the same family that includes the plecos and bristlenose cats. Whiptails and twig catfish have long, slender bodies. However, whereas whiptails are flattened from top to bottom, twig catfish have a more cylindrical shape. Whiptails are omnivorous catfish that like to forage on sandy substrates for worms and insect larvae. Various species are imported, mostly small species such as Rineloricaria parva, a sand-colored species that gets to about 4 inches in length. The giant whiptail catfish (Sturisoma aureum) is bigger, growing to 6 inches in length, while the color-changing chameleon whiptail (Pseudohemiodon apithanos) may grow as large as 12 inches. Most are not demanding, provided water quality is good and they have plenty to eat. Note that while catfish pellets and algae wafers are enjoyed, their diet must include some meaty treats, too, such as frozen bloodworms. Whiptails make a great alternative to Corydoras in a community tank.
Twig catfish are much more demanding. Various Farlowella species are imported, but they are notoriously difficult to tell apart. All get to about 6 inches or so in length, are pencil-thin and need extremely good water quality to do well. Water temperature shouldn’t be too high, and there needs to be a strong water current because these fish are sensitive to low oxygen. Unlike the adaptable whiptails, twig catfish feed primarily on green algae and the tiny invertebrates that encrust rocks known to biologists as aufwuchs. Replicating this diet in aquaria is not easy, but success can be had with a mixture of algae wafers, small frozen foods and the occasional suitable live foods, such as bloodworms. Don’t expect twig catfish to do well when kept with other bottom-feeders, but they mix fine with danios and other stream-dwelling fish.
Both twig catfish and whiptails are usually peaceful toward one another, even gregarious. Males may spar, but when given sufficient space, they’ll coexist. The smaller whiptail species are easy to breed in aquaria, along much the same lines as bristlenose cats.
This velvety black pleco with blue eyes was once commonly traded, and during the late 1980s and early 90s, I kept one in my community tank. Unfortunately for the hobby, this catfish comes from a part of Colombia that became more dangerous to visit. Collectors couldn’t get to the Rio Magdalena region where this catfish lives, and by the mid-90s, it had all but vanished from the trade. So when occasional specimens did come up for sale, the prices were simply astronomical, often in the thousands of dollars. Fortunately, the blue-eyed panaque is starting to make a comeback, though it’s still a pricey fish.
Re-creating the Amazon
South American plants are widely traded, including Amazon swords (Echinodorus bleheri, E. osiris, etc.). Other reliable aquarium plants from this part of the world include Cabomba furcata, Ceratophyllum demersum, Heteranthera zosterifolia, Hydrocotyle leucocephala, Limnobium laevigatum and Myriophyllum aquaticum.
However, despite the variety of plants available, aquatic plants are not particularly characteristic of South American rain forest biotopes. In fact, the streams and rivers that wind through the rain forests are rather dark and gloomy and largely devoid of aquatic plants.
South American river systems are strongly seasonal, as well. Between December and May, the Amazon passes through a wet season flooding phase when it overflows its banks and extends through the forest, turning what was dry land into swamplike flooded forest. During this phase, fish are able to swim about the forest, and for many of them, this is the key period of time to feed, grow and reproduce. Between June and November, the water level drops, and the Amazon again becomes confined to its major river channels, leaving behind a forest that includes countless isolated swamps, ponds and lakes. Exposure to dry air for several months of the year makes it hard for true aquatic plants to become established, and many of the best-known South American species, including Amazon swords, are actually marsh plants able to tolerate submersion for part of the year and then exposure to air for the rest.
Replicating this dynamic environment in the aquarium isn’t easy, but there are some obvious keynotes. Use subdued lighting, a lot of bogwood to replicate tree trunks and fallen branches, silica sand to replicate the sandy substrate typical of Amazonian rivers and Indian almond leaves to re-create leaf litter.
Older aquarium books usually list this fish as Panaque suttoni or P. suttonorum. Ichthyologists now think that’s a different fish and it is in fact Panaque cochliodon. By the way, take care not to confuse the blue-eyed panaque with Hypostomus cochliodon, formerly known as Cochliodon cochliodon, a rusty brown pleco that may well be the same thing as the rusty pleco (Hypostomus L-077).
Maintenance of the blue-eyed panaque is similar to that of the widely traded royal panaque (Panaque nigrolineatus). The main difference between them is that the blue-eyed panaque prefers a temperature between 72 and 75 degrees, whereas the royal panaque does well across a broader range of temperatures (from 72 to 82 degrees). Soft, slightly acidic water is best, but blue-eyed panaques are pretty adaptable once settled. As with all plecos, look for active specimens with round bellies and bright eyes; avoid lethargic specimens with hollow bellies or sunken eyes. Newly imported specimens can be susceptible, so quarantine them before putting them in the display tank. Panaque species are simply susceptible across the board, but internal parasites and starvation seem to be the key issues.
The blue-eyed panaque is aggressive and territorial toward their own kind and other plecos, but they are otherwise peaceful, ignoring even tiny tetras and livebearer fry. Optimal diet is a matter of debate, with some evidence suggesting that they consume and digest wood alongside other plant material and small invertebrates. Certainly, their spoon-shaped teeth are well-adapted for rasping away at decaying wood. Under aquarium conditions, they actually seem to be quite adaptable, and while bogwood must be provided (as part of their diet), they will do well on a mix of algae wafers, sweet potato, zucchini, cooked peas and lettuce leaves. Meaty foods are enjoyed, but they should be weekly treats rather than staple foods.
Maximum length is more than a foot, which is a bit bigger than the average royal panaque. Be aware that all Panaque species destroy plants, even plants like Anubias, which is otherwise left alone by herbivorous fish. They also produce vast amounts of feces, so a spacious, heavily filtered aquarium is absolutely essential. A 75-gallon tank would barely be adequate; this is a catfish for unplanted tanks upwards of 100 gallons in size.
This list barely scratches the surface of fantastic catfish from South America and doesn’t include some real characters like the beautiful little driftwood catfish (Tatia perugiae) and the enormous but gentle mother-of-snails catfish (Oxydoras niger). What should be clear is that South American catfish offer something for everyone, and few community tanks won’t be improved through the addition of a carefully chosen South American catfish. AFI
Neale Monks studied zoology at the University of Aberdeen in Scotland and received a Ph.D. in paleontology at Imperial College, University of London. He worked as a marine biologist and now writes for major fishkeeping magazines.