Colombia

The marbled headstander, Abramites hypselonotus, is an anostomid from the Amazon, Orinoco and Paraguay-Paraná basins in South America. An ecological generalist, it occurs in turbid main river channels, minor tributaries and backwaters, and enters inundated zones during the annual floods. Best kept as a group in a large tank alongside cichlids, characins and catfishes, it may nip long or trailing fins and eat soft-leaved plants.

The chocolate talking catfish, Acanthodoras cataphractus, is a doradid catfish from the northern Amazon basin and Atlantic drainages of the Guianas. It is most often exported as bycatch among Platydoras armatulus and is sold under the same trade names as A. spinosissimus, which has pale blotches on the back between the dorsal and caudal fins where this species has pale lines or no markings. Largely nocturnal and gregarious, it is best kept in a group of at least four.

The chocolate talking catfish, Acanthodoras spinosissimus, is a doradid catfish from the northern Amazon basin and the Essequibo in Guyana. Usually exported as bycatch among Platydoras armatulus, it is sold under the same trade names as A. cataphractus, and the most useful difference is the pale blotches on its back between the dorsal and caudal fins. Largely nocturnal and gregarious, it is best kept in a group of at least four.

The spotted talking catfish, Agamyxis pectinifrons, is a doradid catfish from the Amazon basin in Bolivia, Brazil, Colombia and Peru. Very common in the trade, it is hardy and relatively long-lived, and recommended to beginners and experienced aquarists alike despite its adult size. It closely resembles A. albomaculatus, known only from the Río Orinoco drainage in Venezuela, and the two are probably sold under the same trade names.

The manduba, Ageneiosus inermis, is a large auchenipterid catfish found throughout much of South America east of the Andes. At around 470 mm SL it would need an aquarium in excess of 400 x 120 cm as an adult and is largely unsuitable for private aquaria. An obligate carnivore, it can take surprisingly large prey, and the larger Ageneiosus species are often used as food fishes in their native countries.

The duck catfish, Ageneiosus ucayalensis, is an auchenipterid catfish described from Peru and recorded across the Amazon, Orinoco and Guianas. Body patterning apparently varies with locality, and fish from black water habitats, particularly on the Guiana Shield, tend to be darker. Growing to around 290 mm SL and capable of taking large prey, it is safe only with similarly sized catfishes or large pelagic characins, mostly a combination for public aquaria.

L147 is an undescribed Ancistomus species, a suckermouth catfish from tributaries of the middle Río Orinoco in Venezuela and the lower Río Meta in Colombia. Some reports suggest it occurs further up the Meta system, around Villavicencio, some 600 km upriver. It spawns in caves with the male responsible for brood care, and has been bred regularly in aquaria.

The redspot dwarf cichlid, Apistogramma alacrina, is from the Río Guaviare (Orinoco) and Río Orteguaza (Amazon) drainages in Colombia. It differs from all other described members of the genus in having dark blotches at the dorsal and ventral base of the pectoral fins. Three very similar fishes coded A106, A107 and A108 may or may not be conspecific with it, since they show some differences in colour pattern and morphology.

The two-striped dwarf cichlid, Apistogramma bitaeniata, ranges across the Peruvian, Colombian and Brazilian Amazon, from the Marañón to the Tapajós. Also known as the banded dwarf cichlid, it occurs in several colour forms depending on locality, loosely grouped as 'red', 'blue', 'orange' and 'yellow' in the hobby. Many locality names are in use for these forms, and several are regularly applied incorrectly.

Apistogramma brevis is a dwarf cichlid from the Rio Uaupés basin in far northwestern Brazil and the Rio Tiquié in southern Colombia. It has also been recorded in the upper Rio Negro and Rio Orinoco, and inhabits slow-moving blackwater streams where the pH can drop as low as 4.0 or 5.0. Coded A168, it is the type species of the A. brevis group, and breeding is not too difficult if very soft, acidic water can be provided.

The cockatoo cichlid, Apistogramma cacatuoides, is a small cichlid from the upper Amazon basin, from the Ucayali in Peru to the Solimões in Brazil. It lives in slow tributaries, backwaters and creeks where leaf litter collects. Numerous line-bred forms such as 'double red' and 'orange flash' are traded, and captive-raised fish suit a community aquarium, while wild fish are best kept alone or with small dither fishes.

Apistogramma eunotus is a dwarf cichlid from the Río Ucayali in Peru and the Solimões/Amazon in Colombia and Brazil, as far east as the Japurá. Coded A73 under the DATZ system, it has similar-looking, possibly conspecific populations referred to as A74 to A77 depending on locality. It inhabits slow-moving streams, creeks and tributaries, and captive-raised fish are the recommended choice for the community aquarium.

Apistogramma hongsloi is a dwarf cichlid from the Río Vichada and middle Río Meta basins in Colombia and the middle Orinoco in Venezuela. Coded A110 under the DATZ system, it has similar-looking, possibly conspecific populations referred to as A111 to A115 depending on locality. It lives in small tributaries and still waters, and males grow to 55 to 60 mm and females to 40 to 45 mm.

Apistogramma macmasteri is a dwarf cichlid known only from the Río Guaytiquía and Río Metica basins in the upper Río Meta system, Colombia. Coded A120 under the DATZ system, it has a similar-looking, possibly conspecific population referred to as A122, and A121 is the ornamental 'red' form. Captive-raised fish are the recommended choice for the community aquarium.

Apistogramma sp. 'breitbinden' is an undescribed dwarf cichlid from the upper Rio Negro in Brazil, the Venezuelan Orinoco and the Inirida in Colombia. The German name means 'broad-banded' and refers to the uniformly broad suborbital stripe of males. Known in the hobby for several decades, it is often imported as bycatch among shipments of wild-collected A. iniridae, and some populations carry the DATZ codes A164, A165 and A167.

Apistogramma sp. 'Kelleri' is an undescribed dwarf cichlid known only from minor jungle tributaries near Leticia, Amazonas department, Colombia. First collected in 2008, it was exported again in 2009 and 2010 as A. sp. 'Jutai' and A. sp. 'diamond face', with a Brazilian collection site the exporter later corrected to Leticia. It has also appeared on trade lists as A. sp. 'Leticia', and belongs to the A. barlowi complex.

The red edge apisto, Apistogramma viejita, is a dwarf cichlid from the upper Meta basin, part of the Orinoco system in Colombia. Many forms of A. macmasteri enter the trade incorrectly labelled viejita. Male A. viejita have a dark top edge to the dorsal fin and A. macmasteri does not. It inhabits shallow, slow-moving shoreline water with abundant riparian and emergent vegetation, often in savannah country.

The black ghost knifefish, Apteronotus albifrons, is a weakly electric knifefish from the upper half of South America, from Colombia to Paraguay. Usually sold at around 4 inches, it grows to 50 cm and needs a long-term housing plan. Its eyesight is very poor, and it navigates, finds prey and communicates using a weak electric field. In the wild it lives in swiftly flowing streams and rivers over sand.

The Colombian shark catfish, Ariopsis seemanni, is an ariid catfish from river mouths along the Pacific coast of the Americas, from Mexico to Peru. Usually sold as a silvery 2 to 3 inch juvenile, it grows to 350 mm SL and lives mostly in brackish water, so it is not recommended to those lacking the facilities to house it for life. Venom glands at the base of the first dorsal spine can cause a painful swelling.

The oscar, Astronotus ocellatus, is a large cichlid widely distributed in the Amazon region, recorded from Colombia and Venezuela south to Argentina. It grows to 350 mm SL and typically lives 10 to 20 years, both of which need taking into account before purchase. Most fish on sale come from commercial breeders in Eastern Europe or the Far East, in numerous ornamental strains, and genetic analyses suggest the genus contains additional, morphologically cryptic species.

The two spot astyanax, Astyanax bimaculatus, is a characid ranging from Panama through most of the Amazon and Orinoco basins. It lives in a wide variety of biotopes, from swiftly-flowing rivers and streams to ponds, ditches and reservoirs. The name is currently applied to what is considered a species complex of at least four taxa, and aquarium fish most often arrive as contaminants among shipments of other species.

The ruby tetra, Axelrodia riesei, is a tiny characid known only from the upper Río Meta basin in Colombia, part of the Orinoco system. It is less often seen in the hobby than A. stigmatias, presumably because of its remote, restricted range, and differs from it in its deeper body and red colour, which can fade after a period in aquaria. It is said to inhabit blackwater environments, and its small size and somewhat specialised requirements make it a poor community fish.

Known as L239 before description, Baryancistrus beggini is a small loricariid from the Orinoco and lower río Guaviare in Venezuela and Colombia. Its body and fins are uniformly black to brownish with a turquoise to bluish sheen. Placement in Baryancistrus is tentative. Territorial with conspecifics but somewhat delicate, it is not recommended for the general community aquarium.

The Orinoco eartheater, Biotodoma wavrini, is a geophagine cichlid from the Orinoco and rio Negro basins of Venezuela, Colombia and Brazil. One natural habitat is the Río Cinaruco, a low-nutrient blackwater tributary of the Orinoco. It can be told from B. cupido by its noticeably elongate body and a dark flank blotch on or below the upper lateral line. Unless breeding it is surprisingly peaceful, and trade populations include 'Cuao', 'Orinoco', 'San Antonio' and 'Sipapo Ventuari'.

Boulengerella maculata is a pelagic ctenoluciid found throughout much of the Amazon, Orinoco and Tocantins river systems. Colour pattern varies considerably, with some specimens much paler than others, and this may be correlated with water type. Random dark spots on the upper body, and a dark stripe only behind the eye when one is present, separate it from the similar B. lateristriga. It reaches 329 mm SL and needs an aquarium with base dimensions of 240 by 90 cm or more.

The zebra shovelnose, Brachyplatystoma tigrinum, is a pimelodid catfish from the upper Amazon basin in Brazil, Colombia and Peru. Adults appear to be obligate inhabitants of main river channels with strong flow, often around cataracts and rapids, and most aquarium fish are juveniles collected around Iquitos in Peru. It is sometimes confused with B. juruense, especially when young, but has a more well-defined colour pattern, a slenderer body and longer barbels.

Brochis delphax, long known as Corydoras delphax, is an armoured catfish from the Río Inírida and other parts of the upper Orinoco basin in Colombia. The name is used often in the trade, sometimes for misidentified congeners, while B. delphax itself is often traded as C. punctatus. A relatively elongated snout, body spots that fade in adults and spots in the caudal fin are said to separate it from B. agassizii, Hoplisoma brevirostre and others.

Brochis gomezi, long known as Corydoras gomezi, is an armoured catfish from the western Amazon basin in Colombia and Peru, including the 'Tres Fronteras' region. Collection records are scarce and its range is unclear. It resembles B. leopardus, B. orphnopterus, C018 and C131, but has separate, distinct spots on the upper body, six bands on the caudal fin and a relatively slender body.

The emerald 'brochis', Brochis splendens, long known as Corydoras splendens, is an armoured catfish recorded throughout much of the Amazon basin in Brazil, Peru, Ecuador and Colombia. It is sometimes called the 'common brochis', and juveniles are sometimes traded as 'hi-fin cory' for their enlarged dorsal fin. Its 10 to 12 dorsal-fin rays separate it from B. britskii and B. multiradiata, the other two species long kept in Brochis, and certain populations are thought likely to represent distinct species.

The blackwing hatchetfish, Carnegiella marthae, is a small freshwater hatchetfish from the upper Orinoco in Venezuela and the rio Negro in Brazil. It appears to be a stenotypic inhabitant of blackwater, found in igapó and igarapé habitats with overhanging vegetation and leaf litter. Very peaceful but small and timid, it is best kept in a group of 10 or more with similarly sized, peaceful fishes.

The marbled hatchetfish, Carnegiella strigata, is a hatchetfish from the Amazon and Orinoco basins and coastal rivers of Guyana and Suriname. Popular in the hobby, it is collected for the trade mostly in the rio Negro basin in Brazil. Its larger size and dark, marbled pattern set it apart from congeners, though the pattern varies and the wide range may be open to question. It appears to live only in blackwater.

The wimpel piranha, Catoprion mento, is a scale-eating fish from Colombia, Venezuela, Guyana, Brazil and Bolivia. Though not a true piranha, it resembles them and is quite closely related to Pygocentrus species. The common name comes from the German 'Wimpel' (banner), after the extensions to the leading dorsal-fin rays in mature fish. Adults are best housed alone, and it is sensitive to poor water quality and to swings in chemistry.

The blue whale catfish, Cetopsis coecutiens, is a cetopsid catfish from the Amazon, Tocantins and Orinoco river basins. In the wild it swims in voracious feeding groups, homing in on weakened fish by smell and burrowing into prey. It will bite chunks out of tankmates much bigger than itself, so it is best kept alone, and at up to 26.5 cm it needs a large tank with strong water flow and dim lighting.

The striped bulldog pleco, Chaetostoma formosae, is a suckermouth catfish from piedmont streams of the upper Meta and Guaviare systems in Colombia. The commonest member of the genus in the hobby, it is still misidentified as C. thompsoni and sold under several names and L-numbers. An obligate inhabitant of fast-flowing headwater streams, it needs clean, well-oxygenated water with strong flow and does best in a dedicated species set-up.

The pink-tailed chalceus, Chalceus macrolepidotus, is a large characin found throughout northern South America, from Colombia to French Guiana. It inhabits the surface layers of highly oxygenated rivers. Its very large scales tend to fall off during transport, so new imports can be delicate, though once acclimatised it usually proves fairly hardy. It does best singly or in a group of more than six, since smaller groups tend to scrap.

The spotted headstander, Chilodus punctatus, is a headstander from much of the Amazon, the western Orinoco and coastal rivers of Guyana and Suriname. Also called the 'checkered headstander', it lives in slow-moving rivers, oxbows and floodplain lakes, and its colour pattern appears to vary with locality. Shy and peaceful, it is sensitive to dissolved organic wastes and should never be introduced to a biologically-immature aquarium.

The banded puffer, Colomesus psittacus, is a large puffer of coastal waters from Colombia and Venezuela through the Guianas to northeastern Brazil. It also occurs in Trinidad and Tobago and the Caribbean islands, and inhabits mangrove swamps, estuaries and the lower reaches of rivers. Growing to 290 mm SL, it is the largest of its genus and has six dark bands across the back. Likely to prove aggressive in all but the largest systems, it is not a popular aquarium fish.

The red-spotted tetra, Copeina guttata, is a lebiasinid from the middle and upper Amazon basin in Brazil, Peru, Ecuador and Colombia. Reaching 76 mm, it needs a tank of at least 120 x 30 cm. The eggs are apparently deposited in a shallow depression dug in the substrate and guarded by the male. Like many fishes from pristine environments it is intolerant of organic pollutants and requires spotless water.

Copella eigenmanni is a small lebiasinid from the Orinoco system in the llanos of Colombia and Venezuela, including the Meta, Caroní and Apure. It turns up in the trade from time to time among wild-caught fishes from the Orinoco basin. Colombian populations were formerly called C. metae until Zarske (2011) synonymised the two. A broad dark stripe runs from the snout to the eye, and the eggs are laid among vegetation and guarded by the male.

Fowler's cory, Corydoras fowleri, is a long-snouted armoured catfish from the Amazon basin in Peru. Also known as the 'huanta cory' and 'milegros cory', it is often confused with C. coriatae and C. semiaquilus, and aquarium fish are regularly misidentified. Most long-snouted cories grow larger and are more aggressive than other Corydoras, and this one is suitable only for larger community aquaria.

The swordtail characin, Corynopoma riisei, is an unusual tetra from northern Venezuela, the Villavicencio area of Colombia and the island of Trinidad. Males have caudal glands that release pheromones to attract females, plus gill glands found in only a handful of glandulocaudinids, and females are inseminated by the males. Mainly a surface dweller, it needs open swimming space and a group of at least 6-8, since males can squabble.

The sailfin characin, Crenuchus spilurus, is a crenuchid from much of the Amazon and Orinoco drainages and coastal rivers of the Guianas. The only described member of its genus, it varies considerably in colour pattern and morphology across that range. It lives in tea-stained forest streams, and its timid, predominantly benthic nature means it does not always make an ideal community fish. Males guard eggs laid on the roof of a small cave, often formed from leaf litter.

The gar characin, Ctenolucius hujeta, is a predatory pike characid from the Lake Maracaibo basin in Venezuela west to the Río Sinú in Colombia. Also traded as 'freshwater barracuda' and 'hujeta gar', it is surprisingly peaceful with anything too large to swallow. Juveniles school readily, and it is best kept in numbers of four or more with placid fishes that feed from the substrate. It is much the commoner of the two Ctenolucius in the hobby.

Cynodon gibbus is a cynodontid from much of the Amazon basin, the middle and lower Orinoco, and the Rupununi River in Guyana. A pelagic fish of main river channels and larger tributaries, it grows to around 280 mm SL. It is rare in the trade but arguably more suitable for the home aquarium than some of its better-known relatives, given its size and relatively docile behaviour. Being easily dominated, it is best kept alone or with similarly sized, non-aggressive fishes.

The twig catfish, Farlowella vittata, is a stick-like loricariid from the Orinoco river basin in Colombia and Venezuela. This is the most common Farlowella in hobbyists' tanks, although much of the literature refers to it as F. acus, which has a shorter, less slender rostrum. It is super sensitive to poor water quality and should only go into an established aquarium with a good biofilm, algae or dried leaves.

The yellowhump eartheater, Geophagus pellegrini, is a cichlid from the Chocó and Antioquia departments of northwestern Colombia. The species is rare in the hobby, and most fish traded under its name are forms of 'G.' steindachneri or occasionally 'G.' crassilabris. Its yellowish colour pattern separates it from those two, the other members of the 'G.' steindachneri group. It is an ovophilous, maternal mouthbrooder.

The red hump eartheater, Geophagus steindachneri, is a cichlid from the Magdalena and Sinú drainages in Colombia and the Río Limón basin in Venezuela. It lends its name to the 'G.' steindachneri group, whose taxonomic placement is unresolved. Colour forms vary with locality, and some appear on trade lists under the synonym Geophagus hondae. The species is an ovophilous, maternal mouthbrooder, and territorial males are best kept with three or more females.

The salt and pepper cory, Hoplisoma habrosum, long known as Corydoras habrosus, is a tiny armoured catfish from left bank tributaries of the upper Orinoco in Colombia and Venezuela. Most records come from the Río Apure watershed in the Llanos, where it apparently favours lagoons, streams, inundated forest and grassland with little flow. Also called 'dainty cory' and 'Venezuelan pygmy cory', it has 2-3 dark markings along the side of the body, against 4-5 in the similar H. cochui.

The false bandit cory, Hoplisoma melini, long known as Corydoras melini, is an armoured catfish from tributaries of the rios Negro, Caquetá and Orinoco in Brazil and Colombia. Its oblique dark bar along the back splits into two above the caudal peduncle, a feature shared only with H. davidsandsi, from which the dark markings on its flanks separate it. The rio Tiquié population is known in the hobby as 'C084', and a similar, slightly larger form from Peru as 'C085'.

The bandit cory, Hoplisoma metae, long known as Corydoras metae, is an armoured catfish endemic to the upper Río Meta, an Orinoco tributary in eastern Colombia. It appears to be absent from the lower Meta and has not been recorded in Venezuela. Also called 'masked' or 'Meta' cory, it has an oblique dark bar on the rear of the body that ends at the caudal-fin base without splitting, and no other dark markings on the body.

The three-lined cory, Hoplisoma trilineatum, long known as Corydoras trilineatus, is an armoured catfish from the Amazon basin in Colombia, Peru and Brazil and coastal rivers of Suriname. Most of the fish sold as C. julii are in fact this species, and the two are very hard to tell apart without knowing where the fish were collected. Peaceful and hardy, it ranks among the very best choices for the newcomer to catfish and is one of the easiest Corydoras to spawn.

The Colombian tetra, Hyphessobrycon columbianus, is a characid that appears to be known only from the Río Acandí in Chocó, northern Colombia. It is also traded as 'blue flame', 'blue-red' and 'Colombian red fin' tetra, and was misidentified as H. ecuadorensis for several years before it was described. Both sexes are silver with iridescent blue in the upper body and bright blood red caudal and anal fins.

The Loreto tetra, Hyphessobrycon loretoensis, is a small characid from the upper Amazon basin in Colombia, Peru and Ecuador. It is relatively popular in the hobby, but most traded fish are wild-caught, so availability can be sporadic. Most records are from forest streams and minor tributaries with tea-coloured water, overhanging vegetation and leaf litter.

The purple tetra, Hyphessobrycon metae, is a characid endemic to the middle Río Orinoco watershed in Colombia and Venezuela. Also known as 'Río Meta tetra', it is often misidentified, and H. peruvianus has repeatedly appeared under its name. The dark band on the caudal peduncle, without a broad dark band along the lower body, separates it from H. peruvianus and H. loretoensis.

The green line lizard tetra, Iguanodectes spilurus, is a characin found throughout the Amazon, Orinoco, Essequibo and Tocantins river systems. The most widespread Iguanodectes species, it has also been called the 'slender', 'spindle' or 'iguana' tetra, and differs from its congeners in its translucent dorsal and anal fins, lack of a red lateral stripe and prominent dark caudal-fin marking. It is sensitive to poor water conditions.

Leporellus vittatus is an anostomid with a huge natural range across the Amazon, Paraná-Paraguay, São Francisco and Orinoco river systems. Unlike most anostomids it is adapted to a benthic existence in flowing water and spends most of its time on or around the substrate. Occasionally exported, it requires quite specialised conditions, an aquarium of at least 210 by 60 cm and ideally a group of six or more.

Leporinus brunneus is an anostomid from the rios Madeira and Negro in Brazil, the Orinoco in Venezuela and Colombia, and the Casiquiare canal. The largest officially recorded specimen measured 256 mm, and an aquarium with base dimensions of at least 210 by 60 cm is needed.

The red-finned pike cichlid, Lugubria johanna, is a large pike cichlid that ranges over much of northern South America. It is known from the Orinoco, Essequibo, Oyapock and Approuague basins among others, mostly in faster moving rivers and streams, and a number of colour forms have developed across its range. Growing to 30 cm, it can be aggressive, especially towards its own kind, and will eat any fish small enough to be considered food.

The bleeding heart tetra, Megalamphodus erythrostigma, is a characid from the upper Amazon basin where the borders of Brazil, Peru and Colombia meet. The best-known of three similar species in the 'bleeding heart' subgroup, it has the reddish humeral spot found in no other characid. Generally peaceful, although adult males are territorial to an extent, it mostly inhabits sluggish tributaries, side arms and forest lakes.

The red phantom tetra, Megalamphodus sweglesi, is a small characid endemic to the upper and middle Río Orinoco watershed in Colombia and Venezuela. It apparently favours minor tributaries, oxbows and flooded forests, and in Venezuela is often found in morichals. Bred commercially in several countries, it has been traded in more than one colour form, and Zarske (2014) concluded that the particularly red form sold as 'red' or 'var. rubra' is conspecific.

The ram, Mikrogeophagus ramirezi, is a dwarf cichlid from the llanos of the Rio Orinoco drainage in Venezuela and Colombia. Among the more popular dwarf cichlids in the hobby, it is produced commercially in huge numbers, and ornamental strains such as 'gold', 'long-finned' and 'balloon' tend to be genetically weak and short-lived. Wild fish are of superior stock but more demanding, and it requires pristine water quality.

The hockeystick pencilfish, Nannostomus eques, is a lebiasinid from the central and upper Amazon, the Orinoco drainage and rivers of Guyana. It swims at an oblique angle, a trait shared only with N. unifasciatus among congeners, and is also known as the 'rocket', 'diptail' or 'tubemouth' pencilfish. Genetic research on rio Negro populations raises the possibility that the species may be a complex of cryptic taxa.

The dwarf pencilfish, Nannostomus marginatus, is a lebiasinid of Guyana, Suriname and the middle-to-lower Amazon in Peru, Colombia and Brazil. Enduringly popular, it lacks the red body colour of males of the related N. mortenthaleri and N. rubrocaudatus, showing three dark lateral stripes with no red or purple between them. Colour varies between populations, and its small size and timid nature make it a poor community fish.

The greenstripe pencilfish, Nannostomus marilynae, occurs in the rio Negro in Brazil and the Río Vichada in the upper Orinoco basin, Colombia. Also known as 'Marilyn's pencilfish', it is rarely traded in numbers and more often seen as bycatch among shipments of Paracheirodon axelrodi. It most resembles N. minimus, but males lack the highly modified anal-fin of that species.

The three-lined pencilfish, Nannostomus trifasciatus, is a lebiasinid widespread in the western Amazon basin in Brazil, Peru, Colombia and Bolivia. Fairly ubiquitous in the trade, it is less demanding than many congeners and a good choice for a newcomer to pencilfishes. Many fish on sale are farmed, and wild populations vary in colour pattern, one being marketed as 'super red' for its unusually long red stripe.

The one-lined pencilfish, Nannostomus unifasciatus, occurs in the upper Amazon and upper Orinoco basins in Brazil, Bolivia, Colombia and Venezuela. A popular aquarium fish, it swims at an oblique angle, a trait shared only with N. eques. It differs from that species in lacking dark brown spots on the body scales and normally having an ocellus in the upper caudal-fin lobe.

The rainbow tetra, Nematobrycon lacortei, is a small characid from western Colombia, considered endemic to the Río San Juan system. All records appear to come from the Río Calima, where it is apparently restricted to small, isolated forest pools. It is very close to N. palmeri in morphology but has a highly distinctive colour pattern, and adult males are territorial to an extent.

The emperor tetra, Nematobrycon palmeri, is a characid endemic to the San Juan and Atrato basins in Colombia. Virtually all fish in the trade are captive bred, and it is hardy and unfussy about water chemistry. Males are told apart from N. lacortei by their blue iris, and the smaller Inpaichthys kerri, often misidentified as this species, has an adipose fin, which Nematobrycon lacks.

The tiger teddy, Neoheterandria elegans, is a small livebearer endemic to the Río Atrato drainage in northwestern Colombia. It appears to be quite rare in the wild and in the hobby. Shy and diminutive, it is best kept alone in a small colony in a heavily-planted tank with exceptionally clean water. The fry are only 2-3 mm long and initially need infusoria-type foods.

The bronze cory, Osteogaster aenea, long known as Corydoras aeneus, is an armoured catfish described from Trinidad and accepted to occur across much of South America. That range looks more like a complex of similar, distinct species than a single one, and fish from outside Trinidad are of uncertain identity. Aquarium fish are almost all commercially farmed, and the names C. schultzei and C. venezuelanus are routinely misapplied to them.

The rusty cory, Osteogaster rabauti, long known as Corydoras rabauti, is an armoured catfish known mostly from the rio Javarí, which forms much of the border between Brazil and Peru. It possibly also occurs in Colombia, but the full extent of its range is somewhat unclear. Often confused with the very similar O. zygata, it can be told apart by the broad dark stripe on the upper body, which extends onto the lower part of the caudal peduncle. An albino form is available on occasion.

The cardinal tetra, Paracheirodon axelrodi, is a small characid from the rio Negro and Orinoco drainages of Brazil, Colombia and Venezuela. Immensely popular in the hobby, it is now commercially bred on a large scale, but a significant proportion of trade fish are still wild caught or come from community-led projects such as Project Piaba. Rio Negro and Orinoco populations differ in colour pattern, and wild fish are less tolerant of deteriorating water conditions than commercially-produced ones.

The green neon tetra, Paracheirodon simulans, is a small characid from the rio Negro and Orinoco drainages of Brazil, Colombia and Venezuela. An exclusive inhabitant of blackwater, it lives only in the upper, terra firme reaches of tributaries and is sometimes traded as 'false neon tetra' or 'blue neon tetra'. A greener lateral stripe that extends to the caudal-fin base and duller red flanks separate it from P. innesi and P. axelrodi.

The bola pleco, Peckoltichthys bachi, is a loricariid catfish from the upper Amazon region in Brazil, Colombia, Ecuador and Peru. It has been assigned several L-numbers, including L146 from Colombia and L232 from the Río Putumayo/Içá, and has been exported under other generic names including Hemiancistrus and Sophiancistrus. Its mottled colour pattern separates it from most Peckoltia species, and it lives among submerged grasses and branches in flowing water along the margins of medium to large rivers.

The black darter tetra, Poecilocharax weitzmani, is a crenuchid recorded from Brazil, Colombia, Peru and Venezuela. It has been collected from the upper Río Negro, Río Orinoco and Río Solimões drainages. Also traded as 'Black Morpho' tetra, it requires specialist care and is notoriously reluctant to accept dried foods. Unlike most small characids it does not form schools, and males are aggressively territorial towards one another. The Peruvian populations may apparently represent an undescribed species.

The black spot piranha, Pygocentrus cariba, is restricted to the Río Orinoco basin in Colombia and Venezuela. Many of its habitats lie within the llanos, and it has been recorded from river channels, tributaries and floodplain lakes, many of them acidic blackwater environments. Specimens over 100 mm SL have a large humeral spot and few spots on the body, which separates it from P. nattereri. It is best maintained alone.

The red bellied piranha, Pygocentrus nattereri, occurs through much of the Amazon basin and south into the Paraná and Uruguay river systems. Famed as a rapacious predator, it is among the most notorious freshwater fishes in the world. According to Herbert Axelrod (1976), the myth began with a feeding frenzy staged for Theodore Roosevelt in Brazil in 1913. Usually only juveniles form aggregations, and the species is relatively easy to breed in the aquarium.

The threespot eartheater, Satanoperca daemon, is a cichlid from the rio Negro, Casiquiare and upper Orinoco systems in Brazil, Venezuela and Colombia. It is mostly observed in acidic, mineral-poor blackwater. Relatively common in the aquarium trade, it is by no means easy to maintain, needing particular attention to space, diet, water quality and chemistry. Two dark blotches on the flank separate it from the similar S. lilith, which has only one.

The demon eartheater, Satanoperca jurupari, is a cichlid recorded throughout much of the Amazon basin in Brazil, Bolivia, Peru, Ecuador and Colombia. In aquarium literature it is frequently confused with S. leucosticta, which has prominent white spots or vermiform markings on the sides of the head. Its precise identity is a confusing issue, and populations from the Tapajós, Xingu, Araguaia and Paraná are genetically distinct and may represent separate species.

The spotfin hatchetfish, Thoracocharax stellatus, is the most widespread neotropical hatchetfish, recorded from much of South America. It is told from its only congener, T. securis, by a prominent dark spot in the dorsal fin, and is sometimes traded as 'platinum hatchetfish'. It feeds almost entirely on insects, and a tightly fitting cover is needed because it can clear several metres in one jump.

The green swordtail, Xiphophorus hellerii, is a livebearer native to southeastern Mexico, Guatemala, Belize and Honduras. Among the world's most recognisable aquarium fishes, it is ubiquitous in the trade, where selective breeding and hybridisation with X. maculatus and X. variatus have produced a bewildering array of ornamental forms. The name is often misspelled X. helleri.

The threadfin acara, Acarichthys heckelii, is a cichlid from the northern Amazon basin in Colombia, Peru and Brazil and the Essequibo in Guyana. The only member of its genus, it grows to around 200 mm and digs incessantly, and it is susceptible to deteriorating water quality. Some adults show sudden, extreme aggression towards conspecifics that can kill weaker fish, and the problem decreases as tank and group size increase.

The saddle cichlid, Aequidens tetramerus, is a cichlid found across much of northern South America, from the Amazon and Orinoco basins to the Guianas. The type species of its genus, it occurs in several colour forms, and fish from Ecuador and Peru are sought after for the red or orange colouration on the lower head and belly. As currently recognised it is likely to represent a group of related fishes, some of which may be described as distinct species.

The horned bristlenose pleco, Ancistrus triradiatus, is a small suckermouth catfish from Colombia and Venezuela, found among rocks in flowing streams. It is often confused with the common bristlenose, Ancistrus sp. (3), and other congeners, and some are so similar that a definite identification needs the collection locality. Imported fish are almost always wild-caught. Mainly vegetarian and peaceful, it is easy to breed once mature.

Boulengerella cuvieri is a pelagic ctenoluciid characin from much of the Amazon basin, the Río Orinoco and coastal drainages of the Guianas. The largest officially recorded specimen measured 675 mm, but it appears to grow larger, possibly beyond 800 mm. Given that size and its natural behaviour it is largely unsuitable for the home aquarium. Its entire dorsal-fin base lies ahead of the anal-fin origin, a character shared only with B. lucius and B. xyrekes among ctenoluciids.

The gold zebra catfish, Brachyplatystoma juruense, is a large pimelodid from the middle Amazon and Orinoco basins, described from the rio Juruá. Adults have broad dark vertical, oblique or branching bands on a pale yellowish body and grow to at least 600 mm. It is sometimes confused with B. tigrinum, especially when young, but has a much less defined pattern, a deeper body and shorter barbels. It suits only public aquaria and a very small minority of private aquarists.

The slobbering catfish, Brachyplatystoma platynemum, is a large migratory pimelodid catfish from the Amazon and Orinoco basins. The name refers to its relatively thick barbels, which give the impression that the fish is drooling. It travels considerable distances along deeper, flowing channels, and sexually mature adults have been observed in the upper rio Madeira basin, some 3000 km from the estuary. It grows to 1000 mm SL.

The dourada, Brachyplatystoma rousseauxii, is a large migratory pimelodid catfish from the Amazon and Orinoco drainages and rivers of the Guianas. Juveniles feed in the Amazon delta, while sexually mature adults are found only in the western Amazon. Some populations cover as much as 5500 km during migration from the delta, the longest known in any freshwater fish, and it is heavily fished during its upstream movement. It grows to 1900 mm SL.

The piramutaba, Brachyplatystoma vaillantii, is a large migratory pimelodid catfish from the Amazon and Orinoco watersheds and rivers of the Guianas. Juveniles feed in the Amazon delta before migrating upstream in massive numbers, when they are subject to intensive capture by commercial and artisanal fisheries. Sexually mature adults have been observed in the rio Caquetá basin, some 3500 km from the estuary. It grows to 1050 mm SL.

Brochis ambiacus, long known as Corydoras ambiacus, is an armoured catfish from the upper Amazon tributaries of Peru, Brazil, Colombia and Ecuador, described from the Río Ampiyacu. Its name is commonly misapplied to similar-looking fishes, particularly B. agassizii, and the colour pattern is variable. Cope described a large black spot covering the front half of the dorsal fin, and fish matching this are far more common in the trade than those matching B. agassizii.

The skunk cory, Brochis arcuata, long known as Corydoras arcuatus, is an armoured catfish from the upper Amazon region in Brazil, Peru, Ecuador and Colombia. It is among the more popular Corydoras in the hobby and is also known as the 'arched cory' or C020. Several similar-looking congeners exist, particularly Hoplisoma urucu, in which the black body stripe ends behind the eye, and the larger C. narcissus from the rio Purus.

The tucanare peacock bass, Cichla monoculus, is a large predatory cichlid from Colombia, French Guiana, Peru and Brazil, including the Rio Solimões. Often sold as small juveniles, it grows to around 80 cm and needs a tank of at least 10 x 3 x 4 feet as an adult, so it is more suited to public aquaria. It is territorial and moderately aggressive and will eat any tankmate small enough to be considered food.

The Orinoco peacock bass, Cichla orinocensis, is a predatory cichlid from the Orinoco basin in Venezuela and Colombia and the Rio Negro in Brazil. One of the smaller peacock bass, it still grows to around 60 cm and needs a tank of at least 8 x 3 x 3 feet as an adult. It is territorial and moderately aggressive and will eat any tankmate small enough to be considered food.

The speckled pavon, Cichla temensis, is a large peacock bass from the Rio Negro, Uatumã and Orinoco basins in Colombia, Venezuela, Guyana and Brazil. One of the largest Cichla species at up to 99 cm, it is more suited to public aquaria and needs a tank of at least 10 x 3 x 4 feet as an adult. Often sold as small juveniles, it is also fished as a sport fish.

Corydoras simulatus is an armoured catfish known only from the upper Meta watershed in Colombia. It can be identified from most similar-looking congeners by its pair of small rictal barbels. The colour pattern varies considerably with collection locality and some forms have been misidentified as other species, while fish with a dark marking on the sides are sometimes referred to as Corydoras sp. 'olga'.

The grass carp, Ctenopharyngodon idella, is a large cyprinid native to the Amur River system in eastern Russia and northeastern China. Adults typically reach 800 to 1200 mm, making it a wholly unsuitable aquarium subject, though an albino form is traded. Widely introduced for aquaculture and weed control, it has caused serious damage to natural waters, and unwanted fish should never be released.

Hemiancistrus subviridis is a suckermouth catfish from the upper Orinoco and Casiquiare drainages in southern Venezuela, where it lives in cracks between granite rocks in flowing water. Known in the hobby as the green phantom plec, it shares the code L200 with Baryancistrus demantoides. Only B. demantoides has a membrane joining its dorsal and adipose fins. It looks very like L128, the blue phantom plec, and along the Orinoco the two fish grade into each other in colour.

Axelrod's cory, Hoplisoma axelrodi, long known as Corydoras axelrodi, is an armoured catfish apparently endemic to the Río Meta drainage in Colombia, a tributary of the Orinoco. Also known as the 'pink corydoras', it has between one and three dark stripes on each flank. It resembles H. loxozonum, C003 and CW021, and all four are sometimes traded as C. 'deckeri'. In H. axelrodi the principal stripe runs around midbody.

Hydrolycus tatauaia is a large, predatory dogtooth characin from the lower and central Amazon, the upper Orinoco and coastal drainages of Guyana. A pelagic species of flowing main river channels, it performs long upstream migrations to spawn. Its adult size and natural behaviour mean only a handful of private aquarists have the facilities to house it long-term.

The giant Raphael catfish, Megalodoras uranoscopus, is a large doradid recorded from the Essequibo, Tocantins and Amazon river systems. It is also known in the US as the 'ripsaw catfish', and older literature often refers to it as M. irwini, now a junior synonym. Growing to 600 to 700 mm, it is very peaceful and can be combined with many other species in suitably sized systems.

The silver arowana, Osteoglossum bicirrhosum, is a large predator from the Amazon basin, plus river systems in Guyana and French Guiana. Reaching 80 cm, it is largely unsuitable for the home aquarium, and although juveniles are readily available, few private aquarists can house an adult long-term. Juveniles have a single dark lateral stripe, while in those of its only congener, O. ferreirai, most of the body and fins are dark.

The ripsaw catfish, Oxydoras niger, is a large doradid catfish from many of the major river systems of northern South America. Reaching 90 cm, it is only for the experienced fishkeeper and best suited to public aquaria. Much more peaceful than its common name suggests, it takes that name from the spines along the lateral line. It was previously referred to Pseudodoras niger.

Tatia galaxias is a wood catfish from the Orinoco river basin in Venezuela and Colombia, dark with small, round white spots like stars. It is sometimes confused with Tatia intermedia, in which the spots are longer and oval.

Hyphessobrycon acaciae is a small tetra known only from streams in the middle and upper Río Guamal, part of the Río Meta system in Colombia. The dark lateral band separates it from most Hyphessobrycon in the Orinoco basin, and it is told from the remaining few by counts of fin rays, teeth and scales. The Guamal drains into the upper Meta, which flows into the Río Orinoco.

The giant bumblebee catfish, Pseudopimelodus bufonius, is distributed throughout northeastern South America, from Venezuela to eastern Brazil. Its range extends from the Lake Maracaibo basin, and it grows to 245 mm SL. The type locality is uncertain but probably Cayenne, French Guiana.