Ucayali

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 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.

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 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.

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 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 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.

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 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.

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 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 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 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.

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.

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.

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 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.

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 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.

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 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 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 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 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.

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 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 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.

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 Miguelito cory, Brochis virginiae, long known as Corydoras virginiae, is an armoured catfish considered endemic to the río Ucayali drainage in Peru. It is sometimes referred to as 'Virginia's catfish', Corydoras sp. 'Sangama' or 'Zangama', and prior to description it was misidentified as both Corydoras bicolor and C. delphax. Peaceful and gregarious, it should be kept in a group of at least four to six.

The elegant cory, Gastrodermus elegans, long known as Corydoras elegans, is an armoured catfish from the western Amazon basin in Peru, Ecuador and Brazil. Unlike most congeners it spends a fair amount of time away from the substrate, often forming groups in midwater. It gives its name to the unofficial 'C. elegans group' of similar species, which includes G. nanus and G. undulatus plus many C- and CW-numbered fishes of uncertain status.

Laetacara thayeri is a cichlid from the middle and upper Amazon basin in western Brazil and northern Peru. It is relatively rare in the aquarium trade. Ctenoid scales on the sides of the head and the lack of a dark spot at the caudal-fin base separate it from all congeners. Males grow larger than females and develop more-extended dorsal, anal and caudal fins.

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 biara, Rhaphiodon vulpinus, is a dogtooth characin found from the Orinoco and Amazon basins south to the Río de la Plata in Argentina. The only member of its genus, it grows to 600 to 800 mm and is an obligate piscivore, and it is suitable only for public installations or the very largest private aquaria. Juveniles are seen for sale quite regularly, most often without adequate information on their long-term care.