Peru

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 polka dot lyre tail pleco, Acanthicus adonis, is a very large loricariid catfish from the rio Tocantins in Brazil. Thought to range across much of the Amazon basin, it is traded as spotted juveniles in quite large numbers despite its patent unsuitability for aquaria. It reaches 600 mm or more, loses its spotted patterning as it matures and becomes increasingly belligerent with age, so it can only be recommended to owners of the largest private aquaria or tropical ponds.

The lyre tail pleco, Acanthicus hystrix, is a very large loricariid catfish from the Amazon region of Brazil and Peru. A handful of records come from the Orinoco in Venezuela. Juveniles are traded in quite large numbers, but it can reach at least 1000 mm in nature and 500 to 600 mm in captivity, and becomes increasingly belligerent with age. Young fish are easily told from A. adonis by lacking its white to yellowish body spots.

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 red-tailed freshwater barracuda, Acestrorhynchus falcatus, is a predatory acestrorhynchid from the northern Amazon and Orinoco basins. It also occurs in coastal rivers of Guyana, Suriname and French Guiana. Its large humeral spot, shaped like an inverted tear drop, separates it from other Acestrorhynchus. Reaching 250 to 275 mm, it needs plenty of open water, and a group must be of comparable size because acestrorhynchids are cannibalistic.

The big-eyed cachorro, Acestrorhynchus falcirostris, is a large predatory acestrorhynchid from northern Amazon drainages and the Orinoco. The two dark body stripes of the A. nasutus group appear only in its juveniles, and at 320 to 350 mm SL it grows far larger than the other members. A black fringe to the rear of the operculum gives it a 'collared' look. It needs open water, and a group must be of comparable size because acestrorhynchids are cannibalistic.

The pike tetra, Acestrorhynchus microlepis, is a predatory acestrorhynchid from northern Amazon drainages and the Orinoco. It also occurs in coastal rivers of Guyana, Suriname and French Guiana. A member of the A. microlepis group, it has a small blackish spot behind the gill cover and is separable from the very similar A. grandoculis only by counts. It tends to take smaller prey such as tetras, and acestrorhynchids are cannibalistic, so a group must be of comparable size.

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 bottlenose catfish, Ageneiosus marmoratus, is a predatory auchenipterid catfish from Guyana, Suriname and the upper Amazon in Peru and Ecuador. Also sold as 'Guyana slopehead', 'dolphin' or 'hammerhead' catfish, it loses much of its black-blotched juvenile patterning as it grows. Surprisingly peaceful with anything too large to swallow, it is active and sometimes skittish, and needs a tank of at least 150 x 60 cm.

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.

The marbled talking catfish, Amblydoras nauticus, is a small doradid catfish from Peru, described from Nauta in the Peruvian Amazon. It is often still sold as A. hancockii, a name now considered a synonym of Platydoras hancockii. Hardy and tolerant of a wide range of water conditions, it is secretive and rarely seen by day. It makes audible sounds by grinding its pectoral spines in their sockets and by resonating the swim bladder, and its spines tangle easily in nets.

The green terror cichlid, Andinoacara rivulatus, is a large cichlid from extreme northern Peru and the coastal drainages of western Ecuador. Generally aggressive and territorial, it is best kept alone or as a mated pair unless the tank is enormous. Males grow substantially larger than females and develop a nuchal hump when mature. Fish from the northern end of its range may represent a different species.

The striped headstander, Anostomus anostomus, is an anostomid from the Amazon and Orinoco river systems in Peru, Brazil, Venezuela and Guyana. It lives along rocky shores of fast-flowing rivers, grazing algae and small invertebrates from the rocks. Although it shoals in nature, it is very quarrelsome with conspecifics when only a few are kept, so it is best kept singly or in a group of 6 or more in a larger tank.

Apistogramma agassizii is a dwarf cichlid found through much of the Amazon/Solimões basin, from the Río Ucayali in Peru to the Capim River in Brazil. Colour and pattern vary considerably with locality, and numerous ornamental forms have been selectively bred for the trade. It inhabits slower-moving tributaries and creeks where leaf litter collects. Captive-raised fish suit the community aquarium, while wild fish are best kept alone or with small dither fishes.

The Inca dwarf cichlid, Apistogramma baenschi, is from tributaries of the lower Río Huallaga in the Amazonian portion of northern Peru. Coded A188 under the DATZ system, it is produced on a commercial basis and is perhaps among the most suitable Apistogramma for those new to dwarf cichlids. Wild fish come from shallow forest tributaries with very soft, tea-stained water and a pH measured between 4.1 and 6.3.

Barlow's dwarf cichlid, Apistogramma barlowi, may be endemic to the Ampiyacu River system, an affluent of the Amazon in northeastern Peru. Adult males have a disproportionately large head with enormous jaws and hypertrophied lips. It is one of only two Apistogramma known to be facultative, biparental, larviphorous mouthbrooders, and apparently favours cool, flowing forest streams (igarapés).

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.

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.

The ash lipped apisto, Apistogramma cinilabra, is a cichlid from shallow blackwater backwaters between Iquitos and Nauta in Loreto, Peru. Males carry the namesake ash-grey lips, red pectoral bases and red spots on the chest, and the body is disproportionately high. The description suggests it may be threatened in its native range, though not enough data exist to confirm this, and the emphasis should be on forming a captive population.

Apistogramma eremnopyge (A218) is a dwarf cichlid known only from Loreto region in northeastern Peru, in the Itaya, Nanay and Tapiche drainages. Traded under names including A. sp. 'strawberry', 'red beard' and 'diamante', it has a dark blotch low on the caudal peduncle in both sexes. Pairs can apparently be kept only when other pairs are visible in adjacent tanks, so a group of several males with more females is preferable.

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.

Known in the trade as the 'panda dwarf cichlid', Apistogramma nijsseni is from tributaries of the Río Ucayali in Loreto Region, northern Peru. Coded A180 under the DATZ system, it inhabits slow-moving blackwater streams and creeks where the pH can drop as low as 4.0 or 5.0 and the substrate is littered with branches and a deep layer of rotting leaves.

Apistogramma norberti is a dwarf cichlid from the Río Tahuayo and Río Tamshiyacu, minor Amazon tributaries south of Iquitos in northeastern Peru. Known before its description as A. sp. 'großmaul' or 'bigmouth', and coded A190, its position within the genus is unresolved and it is only tentatively placed in the A. cacatuoides group. It lives in minor jungle streams whose volume changes significantly with the season.

Apistogramma panduro is a dwarf cichlid from the Río Ucayali drainage and the Río Tahuayo in Loreto Region, northern Peru. Also known as the blue panda cichlid and by the trade name A. sp. 'pandurini', it is told apart from similar species by a lower jaw that extends beyond the upper. It can be quite aggressive towards conspecifics, though pairs often remain monogamous once formed.

The pantaloon cichlid, Apistogramma pantalone, is a small cichlid probably endemic to the Nanay river system in northern Peru. It lives in shallow, hyper-acidic forest streams, and unlike many congeners does not fare well if water parameters deviate far from nature. A facultative mouthbrooder, it has been traded as A. sp. 'Lyretail 1' and is very similar to the closely related A. martini.

Apistogramma paulmuelleri (A52) is a dwarf cichlid apparently endemic to Loreto, Peru, described from a forest stream near the Iquitos to Nauta road. It has been traded as A. sp. 'Apache', a name also applied to other, non-conspecific Apistogramma. Since 2009 parts of the type locality stream have been degraded by removal of riparian vegetation.

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.

Kennedy's tetra, Astyanax kennedyi, is a small characid endemic to the upper Amazon basin in Peru, around the city of Iquitos. Like most Astyanax it is rarely offered for sale, and the occasional specimen turns up mixed among shipments of wild fishes from Peru.

The midnight catfish, Auchenipterichthys coracoideus, is an auchenipterid catfish from the Peruvian and Brazilian Amazon and the Essequibo drainage. Also known as the 'Zamora woodcat', it has often been misidentified as A. thoracatus, and the two differ principally in anal-fin ray count. By day it shelters among submerged roots, tree stumps or vegetation in turbid rivers and flooded areas, emerging to feed in open water at night.

Axelrodia stigmatias is a tiny characid from the western Amazon region in Brazil and Peru, sometimes traded as the 'white star' or 'pepper' tetra. It resembles A. riesei but has a more elongate body and is silvery yellow in life where that species is red. It is said to inhabit blackwater environments, and given its small size and somewhat specialised requirements it is best kept alone or with diminutive, non-aggressive characids and small catfishes.

The cupid cichlid, Biotodoma cupido, is a geophagine cichlid from much of the Amazon basin, north to the Essequibo in Guyana and south to Bolivia. Also traded as the 'green-streaked eartheater', it varies in colour pattern and shape by locality, and most traded fish come from around Santarém in Pará state. Unless breeding it is surprisingly peaceful. Its relatively compact body and a dark flank blotch above the upper lateral line separate it from B. wavrini.

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 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.

Brochis lamberti (C009), long known as Corydoras lamberti, is an armoured catfish known only from the lower Río Pastaza, a tributary of the Río Marañón in Loreto, northern Peru. Similar-looking fish are known from tributaries close to Iquitos, and it is unclear whether these, 'C009' and B. lamberti are the same species. It is rare in the hobby and difficult to identify without collection details, so it may have been traded under other names.

The leopard cory, Brochis leopardus, long known as Corydoras leopardus, is a spotted armoured catfish from the western Amazon basin in Peru, Ecuador, Bolivia and Brazil. It looks very like Hoplisoma julii and H. trilineatum, but has a longer, more pointed snout and grows larger. Dias et al. (2024) moved it to the genus Brochis and put the two lookalikes in Hoplisoma, so the resemblance does not reflect a close relationship. The type specimens were aquarium imports.

Known in the hobby as the hognose 'Brochis', Brochis multiradiata, long known as Corydoras multiradiatus, is an armoured catfish from the northwestern Amazon basin in Ecuador and Peru. Formerly placed in Brochis, it has an extended snout and 17-18 dorsal-fin rays, against 6-8 in other Corydoras. Little is known of its habitat, but it is likely to live in smaller tributaries and still waters such as backwaters and oxbows, as closely related species do.

The false network cory, Brochis sodalis, long known as Corydoras sodalis, is an armoured catfish from the upper Amazon in Loreto, Peru, and Amazonas state, Brazil. It inhabits small tributaries, creeks, pools and areas of flooded forest. Very peaceful, it is best kept in a group of at least six, and it can be spawned in a similar way to other Corydoras.

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 red-tailed brycon, Brycon cephalus, is a large characid from the upper Amazon basin in Peru, Bolivia and Brazil, known in Brazil as the matrinxã. It migrates twice a year over large distances between nutrient-poor tributaries and silt-laden white water rivers, where it spawns. B. rubricauda and B. orbignyanus resemble it closely. An active, pelagic shoaling fish with sharp teeth, it grows to 220 mm SL and needs a very large, well-covered tank as it jumps.

The banjo catfish, Bunocephalus coracoideus, is an aspredinid catfish from Bolivia, Peru and Brazil. The most common member of its genus in dealers' tanks, it inhabits forest streams, lakes and ponds with a lot of leaf litter and is camouflaged to resemble a dead leaf. Largely inactive and secretive, it becomes active only after dark, and like other aspredinids it occasionally sheds its skin.

The pygmy hatchetfish, Carnegiella myersi, is a tiny freshwater hatchetfish from the Peruvian Amazon basin, with a second population in Bolivia. The smallest and most delicate of the nominal hatchetfishes, it has a shallower, rounded keel that gives it an elongate profile. It lives in small, shaded, shallow forest streams and must be kept in a group of at least six, away from active tankmates.

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 oil catfish, Centromochlus perugiae, is a small auchenipterid catfish from Peru and Ecuador. It lives around the shorelines of swift-flowing rivers with sandy substrates and no aquatic plants. By day it squeezes into spaces little bigger than itself, emerging in the evening to feed close to the surface in the flow. It breeds quite easily given strong flow and plenty of small crevices.

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 tucanfish, Chalceus erythrurus, is a large characin from parts of the Amazon basin in Peru and Brazil. It lives in the surface waters of floodplain rivers and lakes. The red or yellow caudal fin separates it from the pink-tailed C. macrolepidotus. Fast and a renowned jumper, it needs a lot of swimming space and a well-fitting cover, and it does best singly or in a group of more than six.

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 red terror, Cichlasoma festae, is a large, territorial cichlid from the Rio Esmeraldas in Ecuador and the Rio Tumbes in Peru. Males reach around 20 inches and females 12, and anything the fish can fit in its large mouth will be seen as food. Pairing is troublesome, since the weaker fish of an incompatible pair is likely to be killed, so a pair is best grown on from six juveniles. An introduced population also exists in Singapore.

The Amazon puffer, Colomesus asellus, is a freshwater puffer found throughout much of the Amazon basin, with records north to Guyana and Venezuela. Also traded as the South American puffer or 'SAP', it is told from congeners by a transverse row of dermal flaps across the chin. It lives mostly in well-oxygenated river habitats, is intolerant of organic waste, and forms loose aggregations, so a group of 6 or more is best, away from the general community.

The black pacu, Colossoma macropomum, is a very large serrasalmid from the Orinoco and Amazon basins in Colombia, Venezuela, Peru, Bolivia and Brazil. Known as the tambaqui in its native countries, it is the second largest scaled fish in the Amazon basin and easily capable of reaching 60 cm in captivity. It is regularly sold as a small juvenile, and releases of outgrown fish have led many wildlife authorities in the US to ban its sale. Wild stocks suffer from gross overfishing in many of its native waters.

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 nattereri is a small lebiasinid widespread in the middle and upper Amazon drainage in Peru and Brazil. It is sometimes traded as C. sp. 'red line', 'spotted tetra' or C. nigrofasciata, and its name was long applied to C. callolepis and C. meinkeni. Of the three it alone has a dark lateral stripe, and it has no more than three rows of red spots on the flanks. It inhabits forest streams and flooded forest.

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 Pastaza cory, Corydoras pastazensis, is an armoured catfish from the upper Río Pastaza basin in Ecuador and the ríos Ucayali and Puinahua in Peru. The Río Tigre form was raised to species status as C. orcesi, a decision not followed by all authorities. The two are relatively easy to tell apart: in C. pastazensis the dark vertical bar breaks up or tapers off low on the body, and the body is peppered with numerous small dark spots.

The Peru black cory, Corydoras semiaquilis, is a long-nosed armoured catfish from the western Amazon basin in Peru and Brazil. A few colour forms are available in the trade, sometimes under invalid names such as C. 'huanta' or C. 'milagros'. Males can be somewhat aggressive towards one another, although with sufficient space no real damage should occur, and a group of at least six is best.

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.

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 porthole catfish, Dianema longibarbis, is a peaceful callichthyid catfish from the Amazon basin in Peru and Brazil. It is named for the row of spots running along the lateral line. All specimens in the trade are wild-caught and new imports tend to be delicate and susceptible to disease, but once acclimatised it usually proves very hardy and can live for over 10 years.

The common hatchetfish (Gasteropelecus sternicla) is a freshwater hatchetfish from South America, described from Suriname. Its distribution is questionable, with records from the middle Amazon, Venezuela, Guyana, French Guiana and the Río Paraguay basin. It spends almost all of its time at or just below the surface. The most frequently seen of the silver hatchetfishes, it is peaceful but nervous and shy.

The Napo cory, Gastrodermus napoensis, long known as Corydoras napoensis, is an armoured catfish from the upper Amazon in Peru and Colombia, including the Rio Napo and Rio Nanay. It belongs to the 'elegans group' of similar species with G. elegans, G. bilineatus and G. nanus. Males show a dark marking in the upper dorsal fin, but females are much harder to identify, especially as G. napoensis and G. elegans occur together and are often sold in mixed shipments.

Geophagus proximus is a large cichlid from the Amazon system in Peru and Brazil, from the río Ucayali along the Solimões-Amazon to the rio Trombetas. Rare in the hobby, its name is often attached to shipments of other Geophagus species. It has a dark preopercular marking, no bars on the flanks and a large, roughly oblong midlateral marking. It is found mostly in the lower reaches of rivers and in floodplain lakes, favouring clear and black water.

The banded knifefish, Gymnotus carapo, is a gymnotid knifefish recorded across Central and South America, from Mexico to Argentina. Several species once considered G. carapo have been described since 1994, and its massive natural range will likely turn out to be far more restricted. It uses a weak electric field to navigate and communicate, and a modified swimbladder acts as an accessory breathing organ. It grows to 60 cm and is sensitive to many medications, particularly copper.

The black-top mouse catfish, Hassar orestis, is a doradid catfish recorded in Ecuador, Colombia, Venezuela, Guyana, Peru and Brazil. It can be delicate when first imported, and fish without a rounded belly or with sunken eyes are emaciated and seldom survive long. It resembles Nemadoras leporhinus, which has longer first fin rays and a clear dorsal fin with a dark patch at the base. Like other doradids it produces audible sounds, and its pectoral spines tangle easily in nets.

The January tetra, Hemigrammus hyanuary, is a small characin from the Amazon basin in Peru and Brazil. Also known as the costello or green neon tetra, it resembles an elongated head and tail light tetra, H. ocellifer, and is occasionally confused with it. The type specimen came from Lake Hyanuary near Manaus. It inhabits slow-moving rivers, tributaries and floodplain lakes and tends to lose colour in alkaline water.

The golden tetra, Hemigrammus rodwayi, is a small characin native to Guyana, Suriname, French Guiana, Peru and Brazil. Its normal colour is a rather dull silvery grey. In some areas wild fish react to a trematode parasite with metallic gold deposits of guanin in the skin, and these were once described as a separate species, H. armstrongi. Captive-bred fish are not exposed to the parasite, so most 'golden tetras' on sale lack the gold colour.

The featherfin tetra, Hemigrammus unilineatus, is a small characin widespread across northern South America, from Venezuela to Peru and Brazil. Despite its abundance in nature it is not commonly seen in the hobby, and usually turns up only as a contaminant among imports of other species. A very peaceful shoaling fish, it inhabits slow-moving rivers, tributaries, oxbow lakes and ditches, some clear and others murky with sediment.

The Pinocchio whiptail catfish, Hemiodontichthys acipenserinus, is a loricariid from Guyana, French Guiana, Peru, Bolivia and Brazil. Also known as the knob nosed whiptail, it is hard to confuse with any other Loricariid thanks to its diamond shape seen from above and the enlarged tip of its rostrum. Imports often arrive weak from oxygen deprivation and early losses are high, but once acclimatised it is quite easy to keep over the soft sand in which it partially buries itself.

Hemiodus atranalis is a shoaling hemiodontid characin from Guyana, Peru and Brazil, found in floodplain rivers and lakes. Its reported maximum size is only 90 mm, though it probably grows bigger than this. Very active and skittish when first introduced, it usually settles in a large group, and the tank needs a well-fitting cover since it can leap surprising distances.

Hemiodus unimaculatus is a large, shoaling hemiodontid characin from Guyana, Suriname, French Guiana and Brazil. It inhabits floodplain lakes and fast-moving parts of rivers and grows to around 215 mm SL. Somewhat flighty, it needs a spacious, well-covered tank and a large group to settle, and in nature it is known to spawn during the wet season.

The severum, Heros efasciatus, is a cichlid from the Amazon main channel and the Rio Solimoes, also recorded from the Rio Xingu. One of the most popular and readily available cichlids in the hobby, it is sold in the standard green form and in gold. Many buyers do not realise it grows fairly large, often 20 to 25 cm in aquaria, and it needs a tank of at least 120 cm. Outside spawning it is fairly mild-mannered for its size.

The head-and-tail light tetra, Holopristis ocellifera, is a small characin from Guyana, Suriname, French Guiana, Peru and Brazil. Also known as the beacon tetra, it is hardy, inexpensive and one of the best choices for a newcomer to fishkeeping. Wild fish are rarely offered, since it is commercially bred in huge numbers for the trade, and a selectively bred albino form is also available.

The pretty tetra, Holopristis pulchra, is a small characin endemic to the Upper Amazon in Peru, found in slow-moving tributaries under forest cover. Also known as the garnet or black wedge tetra, it is hardy, inexpensive and a good choice for the beginner. The vast majority on sale in the UK come from commercial farms in Eastern Europe, and it does well in most general community tanks.

Hoplisoma copei, long known as Corydoras copei, is an armoured catfish from Peru, apparently endemic to the Río Pastaza basin and possibly the lower Río Marañón. It is not well known and rarely traded. It looks very similar to several congeners, particularly H. acrense and H. cruziense, and little has been written about it since its description.

Hoplisoma loretoense, long known as Corydoras loretoensis, is an armoured catfish from the upper Amazon in Peru, growing to around 50 mm SL. The profile singles out its very long dorsal spine. Nothing is recorded of its habitat.

The panda cory, Hoplisoma panda, long known as Corydoras panda, is an armoured catfish from the upper Amazon in Peru, named for dark and light markings that recall the giant panda. Wildly expensive when first imported in the late 1970s, it is now mass-produced, and virtually all fish in the trade are farmed. Wild fish live in clear and blackwater streams that cool to around 19 °C when Andean meltwater arrives.

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 vampire tetra, Hydrolycus scomberoides, is a predatory dogtooth characin from the central and upper Amazon in Brazil, Bolivia, Peru and Ecuador. Also sold as 'scomb' and 'sabre tooth tetra', it is regularly confused with the much larger payara, H. armatus. At up to 300 mm it still needs a huge tank and specialist care, and newly-imported specimens often refuse anything but live food.

Hyphessobrycon agulha is a small tetra known with certainty only from the rio Madeira system in the Amazon basin of Brazil, Peru and Bolivia. Relatively rare in the hobby, it is occasionally traded as the 'red-tailed flag tetra'. It lends its name to a group of closely-related species with a dark lower half of the body, especially above the anal fin, and it is very peaceful.

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 Peruvian tetra, Hyphessobrycon peruvianus, is a characid known only from the upper Amazon basin in Peru. Popular in the trade, it is sometimes confused with H. loretoensis and H. metae and has repeatedly appeared under the latter name in aquarium literature. A more elongate body, a dark band reaching the tips of the median caudal-fin rays and red markings at the base of both caudal lobes set it apart.

L229 is an undescribed wood-eating suckermouth catfish of the Hypostomus cochliodon complex from the Río Ucayali, Peru. Like others in the group it develops a hump-backed profile and spoon-shaped teeth. It lives around driftwood in flowing parts of rivers and streams, and grows to around 200 mm SL.

L231 is an unidentified Hypostomus, a large suckermouth catfish said to be exported from the upper Amazon region of Peru. Precise details of its origin are lacking. It grows to 250 to 300 mm SL and needs an aquarium of at least 180 by 60 cm, and it is unclear whether it is the same species as the similarly nameless L266.

The chocolate cichlid, Hypselecara temporalis, is a large cichlid from Peru, Colombia, Venezuela and Brazil. It most often inhabits silt-laden, slow-flowing rivers, and has been collected in the Ucayali, Amazonas, Solimões, Amapá and Oyapock. Although it reaches 30 cm, it is quite a placid species and can be kept in a community of large fish in a suitably-sized tank.

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.

The blue tetra, Knodus borki, is a small characid from Colombia and Brazil, found in rivers, streams and tributaries. Its colour is often so intense that many who first see it for sale assume it has been artificially coloured, though it will not develop its best colours in sparse surroundings. It may nip the fins of conspecifics and long-finned fishes, which a group of 8-10 in a larger tank helps to limit.

The striped headstander, Laemolyta taeniata, is an anostomid from the central Amazon basin, also recorded from the Orinoco system in Venezuela. The largest-growing member of the genus, to 288 mm SL, it is rarely seen in the aquarium trade. Something of a habitat generalist, it migrates into flooded forest in the wet season and has been seen in large migratory shoals with Leporinus fasciatus and L. agassizii. Water quality is of the utmost importance, and anostomids are prodigious jumpers.

The sturgeon catfish, Lamontichthys filamentosus, is a loricariid from the central and western Amazon in Brazil, Peru, Ecuador and Bolivia. Above 60 mm SL the pectoral-fin spine extends into a filament that can be over four times the length of the first branched ray, and the dorsal-fin spine carries a similar extension. Relatively common in the hobby but not easy to maintain, it needs clean, well-oxygenated water and a mature aquarium with plenty of algae-covered surfaces.

The sailfin pim, Leiarius pictus, is a large pimelodid catfish from the Rio Orinoco basin in Colombia and Venezuela and the Amazon in Peru and Brazil. Also known as the painted, saddle or marbled sailfin catfish, it reaches around 60 cm and can live for well over 20 years. Juveniles are often sold without adequate information on their long-term care, and a fully-grown fish needs a tank in the region of 240 by 90 by 120 cm.

The South American lungfish, Lepidosiren paradoxa, is found across the Amazon, Rio Paraguay and lower Paraná basins. The only lungfish known from South America, it is an obligatory air breather and survives the dry season by aestivating in a mucous cocoon inside a burrow in the mud. It can reach 125 cm and live for well over 20 years, so whether it should be considered an aquarium subject at all is debatable.

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.

The banded leporinus, Leporinus fasciatus, is an anostomid from the Amazon and Orinoco systems and coastal Guyana, Suriname and French Guiana. Young fish are often sold without warning of their size and requirements, and it is fairly ubiquitous in public aquarium displays. It is frequently confused with L. affinis, and its dark body bars multiply with age, from five in young fish to around ten in adults.

The threespot leporinus, Leporinus friderici, is an anostomid from much of the Amazon system, with further records from the Guianas and Trinidad. It grows to 350 to 400 mm and needs an aquarium with base dimensions of at least 240 by 90 cm. Across this enormous range the fish differ in morphology and, especially, colour pattern.

The false jaguar catfish, Liosomadoras morrowi, is an auchenipterid catfish from the Río Ucayali basin in Peru. It is often confused with its congener L. oncinus, from which it differs in its duller patterning. Nocturnal, peaceful and shy, it will eat small fish during the hours of darkness, and fertilisation is internal, with the male's extended anal fin used in a similar way to a livebearer's gonopodium.

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 serpae tetra, Megalamphodus eques, is a characid with an enormous range through much of the Amazon drainage and the Río Paraguay. Very common in the trade, it is also sold as the 'jewel', 'red minor', 'blood' or 'callistus' tetra, and ornamental strains include 'long-finned' and 'balloon' forms. It has a reputation for nipping the fins of tankmates, although this is most pronounced when too few are kept or space is limited.

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 spotted hoplo, Megalechis thoracata, is a callichthyid catfish widespread across northern South America, living primarily in still waters. Still widely referred to as Hoplosternum thoracatum, it can breathe atmospheric air, absorbing the oxygen through the intestine, and this lets it endure poor conditions in the wild. It is also eaten as a food fish in parts of South America.

The flag cichlid, Mesonauta festivus, is a cichlid recorded from Venezuela, Peru, Brazil, Bolivia and Paraguay. It lives in well planted, slower-moving waters. Flag cichlids are found in most aquatic stores, but the fish usually sold under the name is M. insignis. It is peaceful, but becomes more aggressive when breeding.

The silver dollar, Metynnis hypsauchen, is a relative of the piranhas with a patchy distribution in Guyana, Brazil, Peru and Bolivia. Sometimes called the plain metynnis, it is sold under the same name as the very similar M. argenteus and differs in the black blotch above and behind each eye. A striped form is not a distinct species. An avid plant-eater, it is best kept in a group of at least five.

The ceros tetra, Moenkhausia ceros, is a small characid from the Amazon basin in Peru and Brazil. Rare in the UK hobby, it occasionally shows up as a contaminant among imports of more popular species. It inhabits slow-moving rivers, tributaries and floodplain lakes. Moenkhausia is used as a catch-all for many small characins, and most experts agree the genus needs a full revision.

The South American leaf fish, Monocirrhus polyacanthus, is a predator from Brazil, Peru, Venezuela, Colombia and Bolivia that mimics a dead leaf. It stalks prey head-down, appearing to drift like a leaf, and can swallow prey almost as big as itself. Flighty and very sensitive to deteriorating water quality, it is difficult to maintain and not a species for the beginner, and soft, acidic water is essential.

The redhook, Myloplus rubripinnis, is a relative of the silver dollars from much of northern South America, including the Amazon and Orinoco. Commonly sold as a silver dollar, it can be told apart by its black-trimmed, red anal fin and grows much larger, to around 25 cm. Given a large enough aquarium, correct feeding and good water quality it should not pose many problems. It is still widely referred to as Myleus rubripinnis.

The black-barred myleus, Myleus schomburgkii, is a close relative of the redhook from parts of Venezuela, Peru and Brazil. The black vertical bar on the flanks distinguishes it, and it is a smaller adult fish, though it is sometimes offered for sale as a redhook. Also called the black-ear pacu and disc pacu, it should be kept in groups of at least five, and a tight-fitting lid is a good idea as it moves extremely quickly when startled.

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 coral red pencilfish, Nannostomus mortenthaleri, is a lebiasinid that appears endemic to the Nanay basin and Río Tigre system in Loreto, Peru. Originally described as a subspecies of N. marginatus, it is traded under names including 'red arc' and 'Peruvian red' pencilfish, and males carry bright red between the upper two dark lateral stripes. More aggressive than most congeners, it needs a spacious tank with plenty of broken lines of sight.

The purple pencilfish, Nannostomus rubrocaudatus, is reportedly collected along the Marañón in Peru, between the Morona and Santiago rivers. Before description it was traded as Nannostomus sp. 'purple' or N. sp. 'coral red II'. Males have red-purple pigmentation between all three dark lateral stripes, and it is more aggressive than most congeners, so it needs a spacious tank with plenty of broken lines of sight.

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 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 black band cory, Osteogaster zygata, long known as Corydoras zygatus, is an armoured catfish from the middle Río Marañón watershed in eastern Ecuador and northern Peru. Also known in the trade as the 'zygus cory', it looks very similar to O. rabauti. In O. zygata the broad dark stripe on the upper body stops short of the lower caudal peduncle, and in O. rabauti it extends onto it.

The zebra oto, Otocinclus cocama, is a miniature loricariid from Peru, thought to occur throughout the lower Ucayali and Marañon. Vertically elongated blotches from the dorsal midline to the belly distinguish it from all congeners, and it has a complete lateral line. It can be delicate when first imported and benefits from quarantine in a tank with a good biofilm to graze.

Otocinclus macrospilus, one of the commoner otos in the hobby, is a small loricariid endemic to parts of the Upper Amazon in Peru. It is frequently mislabelled as O. affinis or O. vittatus, and a large round black blotch at the base of the caudal fin separates it from O. vestitus. Imported fish can be delicate, usually through starvation in transit, and do best added to mature, planted tanks.

The neon tetra, Paracheirodon innesi, is a small characid from the Amazon basin in Colombia, Brazil and Peru, found in acidic forest streams. Years of commercial breeding have weakened the ornamental strain, and defects and ill-health are widespread, so stock needs choosing with care. Neons are also susceptible to 'neon tetra disease', a microsporidian infection that is virtually untreatable once advanced.

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 red-bellied pacu, Piaractus brachypomus, is a serrasalmid from the Orinoco and Amazon basins in Colombia, Venezuela, Peru, Bolivia and Brazil. Known as the pirapitinga in its native countries, it is one of the largest scaled fishes in the Amazon basin, with wild fish recorded to 88 cm. Juveniles mimic the red-bellied piranha and are sold small as 'vegetarian piranha', and releases by aquarists have left populations in the USA and elsewhere.

The ornate pim, Pimelodus ornatus, is a pimelodid catfish recorded in major river systems from Colombia and Venezuela south to Paraguay and Argentina. One of the more sought-after pims imported with any regularity, it grows to 28 cm and is a predator that will eat smaller fish. It is scaleless, sensitive to many medications and often in poor shape when first imported, and its rigid fin spines can cause a painful sting.

The pictus cat, Pimelodus pictus, is a small pimelodid catfish from the Rio Orinoco and Amazon basins in Colombia, Venezuela, Peru and Brazil. The most popular member of the genus in the hobby, it is often sold as a bottom dweller for communities of small fish, though it is a predator that will eat neons, guppies and similarly-sized species. Colombian fish are peppered with tiny dark spots, while the Peruvian form has much larger spots on the body.

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 large spot stingray (P53), Potamotrygon falkneri, is a freshwater stingray from the Paraná and Paraguay basins in Brazil, Paraguay and Argentina. A large female can reach about 52 cm across the disc. It is imported irregularly and is usually expensive when available. Like all rays it carries a venomous sting on the tail, and the venom causes intense pain and tissue necrosis.

The motoro stingray, Potamotrygon motoro, is a freshwater stingray ranging across Colombia, Peru, Bolivia, Brazil, Paraguay, Uruguay and Argentina. It reaches about 50 cm across the disc. The patterning is highly variable, with some variants given P-numbers and others sold as 'blue', 'orange', 'black' or 'marbled'. Males are among the most violent when spawning and can seriously injure females.

The glass bloodfin tetra, Prionobrama filigera, is a characid recorded from the Amazon drainage in Ecuador, Colombia, Peru, Bolivia and Brazil. It is told from the other bloodfin tetra, Aphyocharax anisitsi, by its more elongate body and the lack of red in the anal and ventral fins. An active, pelagic species of the upper water layers, it grows to around 6 cm and should be kept in groups of at least six to eight.

The angelfish, Pterophyllum scalare, is a cichlid from the Amazon, Essequibo, Oyapock and other rivers of northern South America. Adults reach 15 cm in body length and 20 cm or more in height, so it needs a tall tank. Almost all fish on sale are mass-produced, in black, gold and koi strains as well as the standard silver, and while generally peaceful it may eat small fish such as tetras.

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 fog talking catfish, Rhinodoras boehlkei, is a doradid catfish from the upper Amazon basin in eastern Ecuador and Peru. It is usually found sheltering among roots or sunken logs in flowing rivers and tributaries. Shy and nocturnal, it is totally unaggressive but will eat smaller fish, so tankmates need to be too big to be considered food.

Rineloricaria morrowi is a loricariid catfish from the Ucayali River basin, Peru, found among leaf litter over sandy substrates. It is seen less often than some others in the genus. Briefly placed in the resurrected genus Hemiloricaria in 2002, it was returned to Rineloricaria within a year, but the old name is still used quite often.