Amazon basin

This species, which may also be referred to by the alternative vernacular names 'spiny catfish', 'painted talking catfish' or 'chocolate raphael', isn't particularly common in the trade and most often exported only as bycatch among shipments of Platydoras armatulus. It appears very similar to the congener A. spinosissimus with the most useful external distinguishing character being the presence of pale blotches on the dorsal surface, between the dorsal and caud...

This species, which may also be referred to by the alternative vernacular names 'spiny catfish', 'painted talking catfish' or 'chocolate raphael', isn't particularly common in the trade and most often exported only as bycatch among shipments of Platydoras armatulus. It appears very similar to A. cataphractus with the most useful external distinguishing character being the presence of pale blotches on the dorsal surface, between the dorsal and caudal fins, in....

This species is not normally aggressive towards conspecifics with juveniles in particular exhibiting a marked schooling instinct. Older individuals tend to be more solitary but still group together from time-to-time, and it's best maintained in numbers of four or more. One important point to note is that acestrorhynchids are can...

The vernacular name of this fish is derived from its appearance and behaviour, rather than a genetic association with the marine barracuda, and it's also sometimes referred to as 'pike characin' or 'spotted cachorro' with local vernacular names including 'Grand dent-chien' (French Guiana), ' Cachorrinho' or 'Ueua' (Brazil). Although most species of Acestrorhynchus appear superficially similar to one another most exhibit distinguishable external chara...

This species is a member of the putative A. nasutus group of closely-related species within the genus alongside A. nasutus, A. maculipinna and A. isalineae. These are characterised by possession of two dark, longitudinal stripes, one running from the tip of the snout to the base and the other from the posterior edge of the lower maxilla to the underside of the caudal peduncle.

This species is a member of the putative A. nasutus group of closely-related species within the genus alongside A. nasutus, A. maculipinna and A. isalineae. These are all characterised by possession of two dark, longitudinal stripes, one running from the tip of the snout to the base and the other from the posterior edge of the lower maxilla to the underside of the caudal peduncle.

An obligate piscivore capable of consuming quite large prey in relation to its body size although it tends to focus on smaller prey such as tetras and related species. Newly-imported specimens may refuse to accept anything but live fishes although most can be weaned onto dead alternatives once they recognise them as edible, and some even learn to accept dried foods.

An obligate piscivore capable of consuming surprisingly surprisingly large prey. Newly-imported specimens may refuse to accept anything but live fishes although most can be weaned onto dead alternatives once they recognise them as edible, and some even learn to accept dried foods- Like the vast majority of predatory fishes this specie...

Known only from the lower Amazon river basin, and possibly restricted to the Xingu and Tocantins watersheds. Type locality is ' Rio Santa Teresa, a western tributary of upper Rio Tocantins, Goiaz State, Brazil', referring to what is now known as Goiás state, central Brazil.

This species, which may also be referred to by the alternative vernacular names 'spotted raphael', 'white-spotted' or 'white-barred' catfish, is very common in the trade and despite its adult size is recommended to beginners and experienced aquarists alike since it is hardy, attractive and relatively-long-lived. The light body markings are highly variable in terms of exact placement and may be either white or pale to darkish yellow in colour. It is very similar i...

The genus Ageneiosus was at one point classified in the family Ageneiosidae alongside the genus Tetranematichthys, but this was not accepted by all authors. The grouping remains poorly-studied with the last major revision having been conducted by Watson (1990) in his unpublished dissertation, in which A. inermis was included under the currently synonymous name A. brevifilis. It can be separated from the majority of the genus (except A. marmoratus) by possession of a truncate caudal fin, and from...

Apparently this species is polymorphic with body patterning varying significantly depending on locality. Individuals collected from black water habitats tend to be noticeably darker in overall colouration, for example, with this being particularly evident among populations from the Guiana Shield. The genus Ageneiosus was at one point classified in...

This species was previously thought to be, and is often still sold as, A. hancockii, a name currently considered synonymous with Platydoras hancockii (Valenciennes 1840). It's also known by the vernacular names of blue-eyed catfish or Hancock's doradid, and in many ways is an ideal beginners' catfish, being hardy and tolerant of a wide range of water conditions...

This species is not always identified correctly with its name used for the unidentified common bristlenose and other similar species, while the fish itself has been referred to as A. hoplogenys and assigned the L-number L183. Images and information describing it it in much of the available literature confirm this confusion.

A somehwhat odd-looking species with a distinctive wide head and overall flattened profile. Unfortunately this fish is not the easiest fish to keep alive in the aquarium since it requires rather specialised conditions and is often in poor condition post-import. As a juvenile, it often sports a pattern of light spots on the body, leading to confusion with the similarly shaped L255 species.In A. ranunculus, these spots fade as the fish mature,...

A somewhat odd-looking species with a distinctive wide head and overall flattened profile. Unfortunately this fish is not the easiest fish to keep alive in the aquarium since it requires rather specialised conditions and is often in poor condition post-import.

A biotope-style set-up could consist of a sandy substrate, piles of smooth rocks and driftwood roots and branches, some of which should penetrate the water surface. Aquatic vegetation can be included if you wish but is likely to be eaten.

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade, some of which include. It has also been assigned the 'A' number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A235, A236, A237, A238, A239, A240, A241 and A242 depending on locality. The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition ...

This species differs from all other described members of the genus by the presence of dark blotches at the dorsal and ventral base of the pectoral fins. Three very similar-looking fishes have been assigned the codes A106, A107 and A108 under the DATZ system and are also known in the aquarium hobby as A. sp. 'rotpunkt' (this form has been in the hobby for decades with its precise origin unclear), A. sp. 'rotpunkt Orteguazas' (the paratype form of A. alacrina) and A. sp. 'rotpunkt Guayas', respectively. It remains to be seen whether they're conspecific with A. alacrina or not since they exhibit some differences in colour pattern and morphology.

This species is assigned the code A188 under the DATZ system and is also known by the trade names A. sp. 'Inca/Inka', A. sp. 'Inka 50', A. sp. 'highfin nijsseni', A. sp. 'Nijsseni 2', A. sp. 'red crescent' or A. baenschi 'Inca'. It's among those members of the genus produced on a commercial basis and is regularly available in the aquarium trade.

Localities known in the hobby include 'Pastaza', 'Putumayo', 'Requena', 'Río Nanay', 'Rio Napo', 'Maniti', 'Momón', 'Río Tigre', 'Río Ampiyacu', 'Shishita', 'Shushupi', 'Yavari', 'Tefé', 'Manaquiri', 'Lago do Januari', 'Mamori' (often misspelled 'Mamuri'), 'Careiro', 'Manacapuru', 'Juruá', 'Curuaí', and 'Purutu' though we've been unable to find anywhere matching the latter name within the species' known distribution, and in fact several of these names are applied incorrectly on a regular basis.

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade. It has also been assigned the 'A' number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A103, A104, and A105 depending on locality.

Apistogrammas are identified by the use of "A numbers"in a similar fashion to the "L number" system used to identify loricariids. Apistogramma brevis is identified as A168. Additionally, apistos are also grouped into type families and this species is the species type of the brevis group. Unlike some apistogramma species, a. brevis occurs only in a relatively small range and has not been found outside this. personata complex gibbiceps group...

Numerous ornamental forms of this species have been selectively line-bred for the aquarium trade, vernacular names for which include "sunset", "sunburst", "double red", "triple red", "gold", "white gold", "orange flash" and "albino". It has also been assigned the 'A' number A200 under the DATZ system with possibly conspecific, related forms similarly numbered A201, A202 and A203 depending on locality. Th...

The form from the rio Içana tends to have more blue markings on the head than that from the Uaupés, while a reddish population apparently collected close to the settlement of Tucana (sometimes mis-spelled 'Tucano') on the Uaupés is sometimes traded as A. elizabethae 'super red'. Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description.

Known only from Loreto region in northeastern (Amazonian) Peru. Type locality is 'Río Pintuyacu, 48 kilometers on road from Iquitos to Nauta, Río Itaya drainage, Province Loreto, Peru' and it's also been recorded from tributaries of the Nanay system in the same area. An additional population is known from the Río Tapiche, a tributary of the Río Ucayali located well over 150 km further south.

The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition many species exist in two or more geographical colour forms which may or may not turn out to be distinct in the future. Hobbyists tend to label these with collection data if available in order to avoid mixing them and the potential of hybridisation.

This species is assigned the code A52 under the DATZ 'A' number system and is also known by the trade names A. sp. 'Apache', A. sp. 'Peru (II)', A. sp. 'Peru-regani', A. sp. cf. regani (Belém) and A. sp. 'carapintada'. Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition many species exist in two or more geographical colour forms which may or ma...

The German term 'breitbinden' translates literally as "broad-banded" and refers to the uniformly broad suborbital stripe seen in males of this 'species' which remains undescribed despite being known in the aquarium hobby for several decades. It's often imported as bycatch among shipments of wild-collected A. iniridae. Some of the populations have also been assigned th...

An obligate predator by nature, but captive specimens readily accept strips of white fish, whole shrimp, earthworms, and similar once they are recognised as food. Adult individuals are unlikely to require feeding on a daily basis with 1-2 meals per week sufficient.

This species is also referred to as 'velvet cichlid', 'red oscar', 'tiger oscar', or 'marble cichlid'. It is a popular aquarium fish although its adult size and typical life-span of 10-20 years must be taken into account before purchase. Numerous ornamental strains are now available, and while care is more-or-less identical for all of them a degree of additional care must be taken with the 'long-finned' variety which is a little less competitive than other forms.

A. bimaculatus is not a popular aquarium fish but is available on occasion exception, most often as a contaminant among shipments of other species. It's identity is also in question to an extent with the name currently applied to what is considered to represent a species complex comprising at least four taxa.

Endemic to pthe upper Amazon basin in Peru, around the city of Iquitos. Most Astyanax spp. are not popular in the aquarium hobby, though the genus is among the most speciose within the family Characidae. A. kennedyi is no exception; you'll rarely see it offered for sale but may find the occasional specimen mixed among other species in shipments of wild fishes from Peru.

This species is also known by the alternative vernacular name of 'Zamora woodcat', and is often misidentified as A. thoracatus. The latter is a valid species and very similar to A. coracoideus in that the coracoid bone is exposed ventrally and covered only by a thin layer of integument in both species. The two differ principally in the number of anal fin rays...

Prior to description this species was traded under the DATZ code L047 or the alternative vernacular name 'magnum pleco'. It can be distinguished from congeners by a combination of the following characters: presence of a broad, light-coloured (usually yellowish) distal band on the dorsal and caudal fins throughout life, slightly reduced in adults. The only other member of the genus to possess such bands is B. xanthellus but in that species they are reduced to small markings at the fin tips in adults, and the body is covered in pale, normally yellowish, spots.

It remains unconfirmed as to whether this fish represents a colour form of B. xanthellus or not since its DATZ code number of L081 is not referred to in the description paper whereas all other codes for 'gold nugget' plecos, i.e., L018, L085, L177 plus the 'Das Aquarium' code LDA060 are mentioned. In addition, one of the specimens in our images was apparently collected at São Félix do Xingu which is significantl...

The genus Baryancistrus can be distinguished from all other loricariids by possession of an enlarged membrane located posteriorly to the last branched dorsal-fin ray. This membrane may or may not reach the supporting structure of the adipose fin and in this way members can be told apart from the genera Oligancistrus, Parancistrus, and Spectracanthicus, in which the dorsal and adipose fins are completely connected, and Hemiancistrus...

Prior to description in 2011 this species was traded under the DATZ code numbers L018, L085, L077 and 'Das Aquarium' code LDA060, while a very similar-looking fish from the lower rio Xingu which has been assigned the code L081 may also represent a form of B. xanthellus but is not mentioned in the description paper. B. xanthellus can be distinguished from congeners by a combination of the following...

Recorded throughout much of the Amazon basin, with its range extending eastwards from the Ucayali system in Peru as far as the Tocantins drainage which flows into the Atlantic alongside the Amazon at its delta. The southern extremity of its range appears to be the Río Mamoré in Bolivia, a tributary of the rio Guaporé, and the northern limit the Essequibo basin, Guyana.

Populations known in the aquarium trade include 'Cuao', 'Orinoco', 'San Antonio', and 'Sipapo Ventuari'. B. wavrini and its congener B. cupido can be separated by body shape and position of the dark blotch on the posterior portion of the flank. In B. cupido the body is relatively compact and the blotch located above the upper lateral line, whereas in B. wavrini the body is noticeably elongate and the blotch on or below the upper lateral line.

At time of writing there exists no scientific evidence that the different populations of this species seen in the aquarium trade (see 'Distribution') represent anything other than a single, widely-distributed species although some exibit minor morphological differences including relative body depth, longer fin rays in the unpaired fins and yellow or orange colouration in the paired fins. There is apparently a form from the upper rio Negro which may turn out to be distinct but it's...

Boulengerella differs from Ctenolucia, the only other genus currently contained in the family Ctenolucidae, by a series of derived features including possession of 87-124 (vs. 45-50) lateral line scales, presence of a strongly (vs. weakly) developed fleshy appendage at the tip of the snout and absence (vs. presence) of fleshy flaps on the lower jaw. Within the order Characiformes the family Ctenoluciidae is also distinguished by a set o...

Both species also possesses a broader dark midlateral stripe on the body which tends to be more well-defined in B. lateristriga than in B. maculata. Colour pattern in B. maculata varies considerably with some specimens noticeably paler than others, for example, and the the broad midlateral stripe usually less intense in such individuals. This does not app...

This species is sometimes confused with B. juruense, especially when juvenile, but can be told apart quite easily by it's more well-defined colour pattern, relatively slender body shape and longer barbels. It was described in the genus Meredontotus, but is currently included in Brachyplatystoma based on a pair of synapomorphies shared by memb...

Several Brachyrhamdia species have developed colour patterns that mimic syntopically-occurring Corydoras spp. throughout the life-cycle, and the remainder may mimic Otocinclus or smaller Corydoras spp. when juvenile. Among other catfishes they're closely-related to members of the genus Pimelodella, but differ in...

Gasteropelecids are commonly-referred to as 'freshwater hatchetfishes' due to their heavily-keeled body shape which has evolved in such a way due to possessing an enlarged, heavily-muscled pectoral girdle, and which resembles the shape of a hatchet head. They are sometimes said to be capable of propelled flight above the water surface by beating their pectoral fins but in fact this is not the case and was disproven by Wiest (1995) who used...

The smallest and most delicate of the nominal hatchetfishes. The rounded keel is shallower than related species, giving this fish a distinctive elongate profile. The family Gasteropelecidae is separated from other Characiformes by the following combination of characters: front...

C. strigata is an enduringly popular species in the aquarium hobby but is not bred on a commercial basis with all fish offered for sale collected in the wild. It can be told apart from other members of the genus by its larger adult size and dark, marbled colour pattern appearing as a series of dark and light stripes running diagonally across the body below the lateral line. This colour pattern is variable and popul...

All members of the family Auchenipteridae are thought to practise internal insemination and females can carry mature, unfertilised eggs and sperm packets inside the body for unspecified periods of time. When conditions are satisfactory fertilisation is triggered and the eggs deposited, and there is n...

The genus Centromochlus is diagnosable by members having the proximal anal-fin radials enlarged and fused to each other at the base, forming a single ossified structure. It's sometimes included in the putative subfa...

Omnivorous and will accept most foods offered, with the stomach contents of wild specimens varying on a seasonal basis but mostly comprising insects and insect larvae (orders Trichoptera, Hemiptera, Homoptera) plus some terrestrial fruits and even scales of other fishes (Sánchez et al., 2003). In the aquarium offer live Daphnia, Artemia, Moina, bloodowrm, etc., vegetable matter in the form of blanched spinach, lettuce, cucumber, fruit, algae wafers, etc., and good quality, sinking dried foods.

This species is also referred to as 'South American puffer', 'SAP', 'Amazonian puffer', 'Peruvian puffer', or 'Brazilian puffer' in the ornamental trade. Within the genus Colomesus, C. asellus can be immediately identified by possessing a unique transverse row of dermal flaps across the chin which is absent in its congeners C. psittacus and C. tocantinensis.

Known from the middle and upper Amazon river basins in Brazil, Peru, Ecuador and Colombia. Type locality is 'Amazon River at Obidos, Cudajas, and Tabatinga; Rio Negro, Brazil.' It apparently practises an interesting reproductive strategy in which the eggs are deposited in a shallow depression excavated from the substrate and guarded by the male.

This species is quite common in the aquarium trade although normally misidentified as the congeners C. nattereri or the very similar C. meinkeni. It was considered synonymous with C. nattereri for a number of years and was also referred to as C. cf. meinkeni by Zarske and Géry (2006) befo...

This species has been widely referred to as the congener C. nattereri in aquarium literature both prior to and post-publication of its official description in 2006. The two can be told apart quite easily by the fact that C. nattereri possesses a dark lateral stripe while C. meinkeni does not. C. meinkeni can be distinguished from all congeners by the followi...

This species is sometimes traded as C. sp. 'red line', 'spotted tetra' or as its congener C. nigrofasciata. In the past it's name was also widely applied to the fish now identified as C. callolepis and C. meinkeni, and this misidentification continues to an extent although the two are easily-distinguished by the fact that C. nattereri is the only one of the three possessing a dark lateral stripe on each side of the body.

The most obvious distinguishing characters are that the black marking in the upper part of the body is restricted to the area beneath the dorsal-fin and extends into the majority of the fin , while the paler patch anterior to it, on top of the head, is yellowish rather than orangish. Additional diagnostic characters have proven unavailable thus far since it was described in a hobbyist magazi...

This species is not well known and rarely traded for the aquarium hobby. Unfortunately diagnostic characters cannot be provided since we’ve been unable to obtain the type description, and little has been written about this species since it was published. It looks very similar to several congeners, particularly C. acrensis and C. cruziensis.

This species is not well-documented but is said to differ from the comparable C. punctatus by possessing larger dark markings on the body which may form an irregular midlateral stripe in some specimens. Unfortunately diagnostic characters cannot be provided since we’ve been unable to obtain the type description, and little has been written about the species since it was published.

The type series was said to have been collected from a "whitewater area", but images of the rio Unini depict a blackwater system typical of the rio Negro basin, and this is supported by empirical evidence. There are sections of rapidly-flowing water so perhaps this is what the author was referring to. Habitats should therefore comprise tributaries and areas of flooded forest where the water is...

In addition, the colour pattern in aquarium fish traded or identified as C. fowleri is highly variable, but it is unclear whether such differences represent diversity within or between populations. Nevertheless, colour pattern is typically used to distinguish them, with fish from Peru possessing a greater extent of dark pigmentation on the body generally referred to...

The congener C. seussi, which is also native to the rio Mamoré, has a similar colour pattern but its snout is noticeably prolonged compared with that of C. gossei, plus there are some subtle differences in pigmentation. There is a third variant which has been referred to as 'CW069' in the aquarium hobby and appears to be somewhat intermediate, with a short, rounded snout as in C. gossei but a colour pattern more reminiscent of C. seussi.

It can be distinguished from the majority of other Corydoras species by its distinctive colour pattern, comprising a uniform, lightish base pigmentation with a dark arched stripe extending over the upper portion of each flank, from the tip of the snout to the caudal-fin base. This is shared with a few congeners, however, including C. arcuatus, C. narcissus, and C. urucu.

It exhibits slightly different behaviour to the majority of congeners in that it tends to swim in midwater and spends a large proportion of its time away from the substrate. Its morphology exhibits corresponding adaptations towards a pelagic existence with a relatively large eye, a more terminal mouth position, more strongly-forked caudal-fin, and more symmetrical body shape than most other Corydoras species.

Endemic to the upper rio Negro basin in Amazonas state, northern Brazil, and Amazonas state, southern Venezuela. One specific locality is Igarapé Muiá (00°09'03"N 66°48'10"W). Type locality is 'Upper Rio Negro, eastern Amazonas, Brazil', which is thought to refer to forest brooks crossing the "new army road", north of São Gabriel da Cachoeira municipality.

C. incolicana was the first recipient of a 'C' number (see below) in 1993 and was described the same year. Unfortunately its description was published in an aquarium hobbyist magazine, and we have been unable to obtain a copy to date meaning its diagnosis is unavailable. It is therefore difficult to identify accurately, not least because its type locality is in a relatively remote area, and there exist a number of superficially similar Corydoras species or populations in the aquarium trade.

Native to coastal river systems south of the Amazon delta in the states of Piauí, Maranhão, Pará, and Amapá, northeastern Brazil. It has been recorded from the rios Guamá (including tributaries such as the rio Ararandeua), Maracanã (rio Peixe-Boi), Morcego, Parnaíba, Piriá, Caeté, Turiaçu (rio Jamari), and Mearim (rio Pindaré). Reports from French Guiana and western Brazil appear to represent cases of misidentification.

Prior to description C. kanei was assigned the 'C' numbers C026 and C046. Among congeners it is most easily-confused with, and sometimes traded as, C. atropersonatus, but can be identified by presence (vs. absence in C. atropersonatus) of dark markings in the anal and caudal fins, presence of numerous, smaller (vs. fewer, larger) dark spots on the body, and an overall darker (vs. paler) base colouration.

Unfortunately diagnostic characters cannot be provided since we have been unable to obtain the type description to date, and little else has been written about this species. There is also confusion regarding whether C. lamberti, the unidentified 'C009', and similar-looking fish collected close to Iquitos are conspecific or not. We include all together here until these issues are resolved.

In the aquarium hobby, the population from the rio Tiquié has been referred to as 'C084', while a similar, but larger, form from the Río Huallaga in Peru is known as 'C085'. Both forms have been marketed as C. sp. 'mega metae'. The existence of multiple, similarly-coloured species which coexist and sometimes form mixed schools is relatively common in the genus.

The genus is included in the family Callichthyidae, of which members are often referred to collectively as 'armoured' or 'mailed' catfishes group due to the presence of bony plates in place of scales on the body. Their taxonomy can be confusing, and numerous undescribed species are also thought to exist.

The form from the Río Tigre, previously referred to as the subspecies C. p. orcesi (Weitzman & Nijssen, 1970) was raised to full species status as C. orcesi by Isbrücker (2001), but this decision does not appear to have been followed by all authorities some of which consider C. p. orcesi a synonym of C. pastazensis. The two species are relatively easy to tell apart by colour pattern; in C. pastazensis the dark vertical...

Known from the Ucayali (río Samiria), Huallaga, Santiago, and Pastaza (ríos Bobonaza and Pindo) river systems in eastern Ecuador and northern Peru. These are all tributary drainages within the middle Río Marañón watershed, a major affluent of the upper Amazon river basin. Type locality is 'Río Hallagua system, Yurimaguas...

This species is currently the only described member of its genus although colour pattern and morphology vary considerably across its range. You may see reference to this species being the only fish species to possess infra-red vision, but other species also possess this ability and we suspect that infra-red plays an important role in the reproductive cycle of many fishes.

This species is rare in the aquarium trade but is arguably more suitable for the home aquarium than some of its better-known relatives given its adult size and relatively docile behaviour. Other vernacular names include 'Dientón' (Peru), 'Perrito' (Ecuador), 'Payara-chata' or 'Payarin' (Venezuela) and 'Icanga', 'Minguilista' or 'Peice-cachorro' (Brazil), some of which are also applied to related species.

It also occurs in the río Caura on the Guyana Shield plus the Ventauri and Mavaca drainages in the middle and upper Orinoco where it’s also known from some white water, referring to turbidity rather than turbulence, habitats. To the north its distribution appears limited by the Las Majaguas dam on the Río Cojedes, a tributary of the Apure where a probable introduced population inhabits the res...

Despite its designation as type species this is among the most frequently-misidentified members of the genus. This is in part because its natural distribution was earlier considered even more extensive than the still-substantial range recognised today, with populations from the Río Orinoco, Guianas and rio Tocantins now recognised as species in their own right.

This species is relatively rare in the hobby but sometimes available from specialist retailers or private breeders. Though described in 1991 it was first collected much earlier and misidentified by Gosse (1976) as G. surinamensis. It's one of just five Geophagus species not to be included in the nominal G. surinamensis 'group' of closely-related species within the genus along with G. gottwaldi, G. grammepareius, G. harreri an...

It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: presence of dark preopercular markings; seven parallel vertical bars on each flank (normally visible only when the fish are stressed, spawning or preserved); vertical bars four and five meet in such a way that they form a 'Y' shape; dark lateral spot positioned within the third vertical bar; caudal fin reddish with variable pattern of iridescent blue spots and stripes.

This species is very rare in the aquarium hobby and may never have been available on a commercial basis although it has been collected, bred and distributed by some private collectors. It's a member of the putative G. surinamensis 'group' of closely-related species within the genus and ca...

This species is rare in the hobby though it's name is often attached to shipments of other Geophagus species. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; no vertical bars on the flanks; relatively large, roughly oblong-shaped dark midlateral marking; caudal fin brownish with 3-5 light stripes on upper lobe and less well-defined stripes or mottled pattern of light spots with narrow dark interspaces on lower lobe.

There are at least two variants available one of which is often traded as G.sp. 'Araguaia orange head'. This is misleading since both are endemic to the Tapajós drainage (see 'Distribution'), and appears to date back to an error in collection locality when the fish were first exported. The two differ in the extent of orange colouration on the head which extends onto the opercle in G. sp. 'orange head (rio Arapiuns form) but is mostly restricted to the area above the ey...

Known only from the rio Pindaré in Maranhão state, north-eastern Brazil which drains into the Baía de São Marcos (St. Mark's Bay) along with the rios Mearim, of which it is sometimes considered a tributary, and Grajaú. Some sections of the Pindaré have been heavily degraded via removal of riparian vegetation for agriculture and habitats destroyed due to resultant siltation. The river is poorly-studied and the conservation status of its fishes mostly unconfirmed so su...

This species is rare in the hobby although other species are sometimes sold under the name. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; four parallel, ventrally-inclined bars on each flank (normally visible only when the fish are stressed, spawning or preserved); dark lateral spot positioned within the second vertical bar; caudal fin red with variable pattern of large, iridescent blue to white spo...

This species may be referred to using a variety of names including 'scomb', 'sabre tooth tetra', 'sabre tusk barracuda', 'dog tooth characin, 'vampire fish', 'Cachorra' or Pirandirá (the latter two names being used in Brazil where they're also applied to congeners). It's regularly confused with the payara, H. armatus, though that species grows considerably larger, is pop...

H. inspector can be told apart from other described species in the genus by the following combination of characters: colour pattern comprising brown to black base with large whitish to yellow spots; adpressed dorsal-fin not reaching the adipose-fin spine; spots on head much smaller than on rest of body; spots in the upper caudal-fin lobe combining to form bands in adults; 24 plates in the mid-ventral series.

Collected from the rio Xingu downstream and in the vicinity of Belo Monte, Pará state, northern Brazil. The majority of its natural habitat is likely to be severely degraded in the near future due to ongoing construction of the Belo Monte dam.

A similar-looking, larger form from the rio Jarí, which enters the Amazon from the opposite bank a few hundred kilometres downstream from the Tapajós has been assigned the code L411. The two can be told apart relatively easily since in L260 the white vermiculations on the body are significantly finer than in L411, in which the black and white components of the colour pattern are of more-or-less equivalent width.

This unidentified species possesses a highly variable colour pattern with the pale, randomly-arranged spots and blotches on the body ranging in colour from whitish to yellowish to rusty orange depending on the specimen. It's regularly confused with similar-looking relativ...

L136 and its variants are collected in the rio Negro basin, Amazonas state, Brazil, and in particular the rio Demini, a northern tributary flowing into the central Negro in the municipality of Barcelos. Collection details for LDA05 and LDA06 are currently unclear but presumably in the vicinity. This unidentified 'species' is highly variable in terms of colour pattern, and it has been assigned a ser...

One of the most enigmatic species in the hobby, this incredible little catfish must rank amongst the most stunning freshwater species known. In the late 1990s and the early part of this century you could buy one of these for as little as twenty pounds. However in 2004, the Brazilian government banned the exportation of the species amid apparent concerns over the exploitation of wild stocks. As yet, the conservation status of the fish has not been confirmed by any scientific proof with the only e...

This species is relatively rare in the aquarium hobby but is occasionally traded as 'red-tailed flag tetra'. It lends its name to the H. aghula group of closely-related species within the genus as proposed by Géry (1977, see below) of which members share the following characters which set them apart from other characids: lower half of the body dark, especially above the anal-fin; usually possessing a laterally-elongate humeral spot, more-or-less united wit...

This species is very common in the aquarium trade and is also referred to as 'jewel', 'red minor', 'blood', or 'callistus' tetra. A number of selectively-bred ornamental strains have been developed, including 'metallic', 'long-finned', 'balloon' and 'fairy-fin'. Characiformes is among the most diverse orders of freshwa...

In the igarapés Baré and Ubim, western Brazil H. erythrostigma was collected from stretches measuring 5-7 metres in width with thick riparian and overhanging vegetation. The substrate was mostly composed of sand and the fish displayed a preference for boundary zones between shallow and deeper water. Conductivity was measured at 14.2-62.1 mS/cm³, dissolved oxy...

Its name appears to have been misapplied to similar-looking fishes occurring throughout much of the middle and lower Amazon in Brazil and Colombia, plus the rio Orinoco drainage in Colombia and Venezuela, and coastal systems of the Guianas. Some of these have been described as distinct species (e.g. Hyphessobrycon amapaensis Zarske & Géry 1998; H. eschwartzae García-Alzate, Román-Valencia & Ortega 2013; H. montagi Lima, Couthino & Woziacki 2014), whereas the identity of others remains un...

The most recent diagnosis appears to be that of Géry (1977), in which it was separated from other members of the group by the following combination of characters: dorsal-fin insertion at or slightly anterior to mid-body; caudal-fin brick red to orange-red; body depth fits less than 3.6 times in SL; head length fits 3.5-4.0 times in SL; caudal peduncle length u...

The majority of records pertain to the rio Guaporé (Río Iténez in Bolivia), the main affluent of the rio Mamoré, which drains the vast tropical wetland known as the Pantanal, and the upper rio Paraguai, which also has its headwaters in the Pantanal but flows in the opposite direction. The Guaporé and Paraguai are connected due to rising water levels during the annual wet season.

Hyphessobrycon melanostichos shares a number of similarities with Hyphessobrycon sp. Blue Ribbon. The former can be differentiated from the latter by a lighter set, more streamlined body , smaller humeral spot and also red colouring, which is not present on the Blue Ribbon tetra. Care and maintenance of the two species is however, virtually the same.

This species is available on a relatively regular basis, although it's sometimes confused with the similar-looking congeners H. loretoensis and H. metae. It can be identified via the following combination of characters as per Géry (1977): elongate in shape with body depth fitting 3.8-3.9 times in its standard length; caudal peduncle narrow, its depth fitting 1.8 times in its length; head short, interorbital broad, snout short and rounded; dorsal-fin insertion an...

This species is a popular aquarium fish and is bred on a commercial basis in several countries, with a selectively-bred albino form also available. Wild specimens are rarely collected due to the low price of the farmed fish, but the origin of the commercial strain is questionable. The species was considered endemic to the rio Tapajós basin, but in the early 1990s fish appearing identical to the aquarium form were photographed in the...

This is the smallest of three similar-looking species most commonly-referred to as the 'bleeding heart' subgroup, the other two being H. erythrostigma and H. socolofi. All possess a reddish humeral spot which is not present in any other characid with other shared characters including possession of 6 -14 maxillary teeth, 7-9 scales above the lateral line, 5-7 scales below the lateral line and 26-33 anal fin rays.

This species is an opportunistic omnivore by nature. The stomach contents of wild specimens from the rio Padauari were composed of fruit remains and aquatic insects with the former constituting 99% and latter 1% of all items consumed. Stomachs of individuals from igarapé Água Boa cont...

Choice of décor is not especially critical although it tends to show better colouration when maintained in a well-furnished set-up with live plants and a dark substrate. A natural-looking arrangement might consist of a soft, sandy substrate with wood roots and bran...

This species is known from the rio Negro within the Brazilan Amazon basin and upper Río Orinoco system in Venezuela. Type locality is 'Rio Adujá, Rio Itú, tributary of middle Rio Negro, Amazonia, Brazil'.

I. geisleri is typically exported for the aquarium trade alongside the similar-looking congener I. adujai (Géry, 1970) but can be identified by presence (vs. absence in I. adujai) of a black lateral stripe on the body beneath the red stripe, and possession of 20-25 (vs. 28-34) anal-fin rays.

Widely-distributed throughout the Amazon, Orinoco, Essequibo, and Tocantins river systems in Brazil, Peru, Bolivia, Ecuador, Colombia, Venezuela, and Guyana. Type locality is 'Rio Cupai [= Rio Cupari], Rio Tapajós basin, Amazon River drainage, Pará State, Brazil'.

L. taeniata is the largest-growing and second most widely-distributed member of the genus although it's a rarely-seen in the aquarium trade. It can be distinguished from all congeners since it uniquely possesses 5 lateral scale rows between the lateral line and dorsal-fin origin (vs. 4 or 6–8 in the remaining species).

This species is relatively common in the aquarium hobby but is not easy to maintain and recommended only for experienced aquarists. It can be told apart from all congeners by specimens larger than 60 mm SL possessing an extended pectoral-fin spine forming an extremely long filament that may be more than four times the length of the first branched pectoral-fin ray (vs. not possessing such a filament in other species of Lamontichthys).

Décor is relatively unimportant and maintenance simple provided sufficient space is available. A natural-style arr...

This species is also referred to as 'black-anded leporinus', 'striped leporinus' and 'eight-banded leporinus'. Young specimens are often traded for aquaria without warning as to their potential size and requirements, and as a result it's fairly ubiquitous in public aquarium displays.

This species was described from Suriname but no specific locality was given. It's currently accepted to occur throughout much of the Amazon river system in Brazil, Peru and Bolivia with additional records from coastal drainages of Guyana, Suriname and French Guiana plus the island of Trinidad (Trinidad and Tobago).

Metynnis lippincottianus is occasionally seen for sale, sometimes under the name of "Silver Dollar". It is easily distinguishable from m. argenteus and m. hypsauchen (which are more commonly sold as Silver Dollars) by its spotted pattern, hence the common name. M. lippincottianus shares a common name with m. maculatus but the two can be distinguished as the spots on m. maculatus are more pronounced. Silver dollars are common and popular fish in the hobby. They are related to piranh...

Metynnis maculatus

This species appears endemic to the upper rio Madeira basin in Bolivia and Brazil. Records exist from the Río Mamoré and Río Guaporé drainages in Bolivia (where the Guaporé is known as the Iténez) and Brazil plus the upper Río Orthon (ríos Tahuamanu and Manuripi). Type locality is 'sand-bank in the Rio Marm...

This is the smallest member of the genus and rarely traded in numbers, though it's a relatively common contaminant among shipments of wild fishes from Manaus. Unlike other Nannostomus spp. it does not exhibit a specific colour pattern of spots or bars at night-time, rather displaying an overall paleness. The family Lebiasinidae is included in the order Characiformes and sometimes split into the nominal subfamilies Lebiasininae a...

This is the type species of the genus, fairly ubiquitous in the aquarium trade, and represents an excellent choice for the newcomer to fishkeeping since it's less demanding than most congeners. It's sometimes referred to as 'Beckford's pencil fish' or 'brown pencilfish'. Don't worry if your fish look different when you switch on the aquarium lights after dark or in the morning as like most Nannostomus species it assumes a cryptic, vertically-barred colour pattern at ni...

Native to the central Amazon basin with records existing from the Madeira, Branco, Trombetas, and Tapajós river drainages, plus the Rupununi basin in Guyana. Although an affluent of the rio Essequibo and thus not officially part of the Amazon basin, the latter is connected to the rio Takutu, a tributary of the upper rio Branco, during the annual wet season. Type locality is given by Fowler as 'Rio Madeira about 200 miles east of W. Long. 62°20', Brazil'.

This species has been referred to the genera Poecilobrycon and Nannobrycon in the past and in the aquarium hobby is also known as 'rocket', 'brown', 'brown-tailed', 'diptail', or 'tubemouth' pencilfish.It's a popular aquarium fish and has an interesting oblique swimming-style, a behavioural trait shared only with N. unifasciatus among congeners. In the original description the colour pattern is given by Steindachner as a brown lateral stripe exte...

There also exist a number of minor differences in colour pattern between populations. For example some Peruvian forms have yellow pigmentation on the body and fins, and those from Guyana and Suriname possess a short red stripe on vertical scale rows 6-9, above the central dark stripe on the body. Rio Negro forms have a similar red stripe but overlapping the central dark stripe and extending along most of the flank, while a form from Colombia has an elongate red stripe which is broken in two beneath the dorsal-fi...

This species is also known as 'Marilyn's pencilfish'. It's rarely traded in numbers and more often seen as bycatch among shipments of other species, particularly Paracheirodon axelrodi. It can be identified by the following combination of characters: three dark lateral stripes (sometimes referred to as primary, secondary, and tertiary); nocturnal oblique bars relatively narrow, with the anterior bar reaching, but not extending past, the anterior base of the dorsal-fi...

This species is traded under various other names including 'red arc pencilfish', 'Peruvian red pencilfish', 'ruby red pencilfish', 'red pencilfish', and Nannostomus cf. marginatus 'red'. It was initially described as a subspecies of N. marginatus but can be identified by the following combination of characters: pronounced sexual dimorphism with adult males exhibiting bright red pigmentation between the central...

In live fish colour pattern is perhaps the most useful way to identify N. rubrocaudatus plus the closely-related N. marginatus and N. mortenthaleri. N. marginatus is immediately distinguished from the other two by the fact it lacks red pigmentation on the body in males, but N. mortenthaleri and N. rubrocaudatus are more easily-confused. Males of N. rubrocaudatus can be told apart fro...

Wild populations vary in colour pattern depending on origin, and some populations have previously been described as distinct species. A form from Peru has a particularly silvery body colour, for example, while another, marketed as 'super red' possesses an unusually long red stripe on the body, extending much of the length of the dark central stripe. A population from around Boa Vista in the rio Branco system, Pará state, Brazil has an ocellus o...