Peru

Abramites spp. are separated from other anostomids primarily on the basis of their relatively deeper bodies and presence of a prominent, post-pelvic median keel, a feature unique to the genus. At time of writing A. eques is the only other species recognised and is native to the Río Magdalena drainage in western Colombia. It can be distinguished by possession of 13-14 bra...

Despite its patent unsuitability as an aquarium subject attractively-coloured juvenile specimens of this species are traded in quite large numbers, although the scarcity of privately-maintained adults would suggest that most fail to reach their potential. The striking, spotted patterning also disappears as this species matures, and since it also becomes increasingly bellligerent with age it can only be recommended to owners of the largest private aquaria or tropical ponds. There exists an albino...

Despite its patent unsuitability as an aquarium subject attractively-coloured juvenile specimens of this species are traded in quite large numbers, although the scarcity of privately-maintained adults would suggest that most fail to reach their potential. The striking, spotted patterning also disappears as this species matures, and since it also becomes increasingly bellligerent with age it can only be recommended to owners of the largest private aquaria or tropical ponds. There exists an albino...

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....

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.

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.

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...

This species may also be seen on sale as 'Guyana slopehead catfish' 'dolphin catfish' or 'hammerhead catfish'. The attractive juvenile patterning is largely lost as the fish grow but this nevertheless remains an impressive predatory species for the larger aquarium. The genus Ageneiosus was at one point classified in the family Ageneiosidae alongside the genus Tetranematichthys, but this was not accepted by all...

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...

Native to extreme northern Peru and coastal drainages of western Ecuador as far north as the Río Esmereldas drainage and possibly beyond. The form from the Esmereldas and above may represent a different species (see 'notes').

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 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 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...

Apistogramma cinilabra

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.

Prior to decription this species was known as A. sp. 'großmaul' or 'bigmouth', and it has also been assigned the code A190 under the DATZ system. 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 also known by the alternative vernacular names 'blue panda cichlid', 'blue sky dwarf cichlid and 'azure cichlid' as well as the confusing trade name A.sp. 'pandurini'. It has also been assigned the 'A' number A183 under the DATZ system with possibly conspecific, related forms similarly numbered A184 or A185 depending on locality. It can be distinguished from similar-looking species by the length of the lower jaw which characte...

Apistogramma pantalone

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...

This species is not recommended to those lacking the facilities to house it for life. Sadly it's all too often seen for sale as an attractive, silvery 2-3" juvenile, supposedly suitable for the general freshwater community tank. To make matters worse, it is also usually given an 'alluring' name such as 'black-finned' or 'silvertip' shark catfish. The fate of the majority of these specimens is in all likelihood a depressing one.

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...

It's most similar to A. riesei but can be told apart by its more-elongate body (depth 4-5 times, vs. 3.1-3.5 times, in SL), live body colour (silvery yellow, vs. red) and suborbital bone structure (almost complete, vs. reduced). The third species, A. lindeae, is quite different posses...

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.

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...

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...

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 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.

Despite the ubiquity of its name in aquarium literature, confusion surrounds its true identity. Given it's the only member of the genus occurring on the island, fish from Trinidad do presumably represent C. aeneus (see our image), but the classification of those from other localities appears far from certain. Today the species is accepted to occur throughout much of South America, and indeed similarly-patterned fish do occur across a large portion of the continent. Some of these, such as the gree...

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.

Unfortunately, precise diagnostic characters cannot currently be provided since we’ve been unable to obtain the type description, and little has been Characters said to separate it from species such as C. ambiacus, C. agassizii, C. brevirostris, C. ephippifer, and C. melanistius include a combination of relatively elongated snout, dark spots on body fading in adults, dark anterior dorsal-fin patch extending to upper extremity of fin, and presence of spots in the caudal-fin.

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...

This species' range is unclear with collection records scarce, although it certainly occurs in the 'Tres Fronteras' region of the western Amazon river basin where the borders of Brazil, Colombia, and Peru meet. Type locality is 'Lakes of the Isla de Mocagua, Amazon River, near Leticia, Comisaría del Amazonas, 3°54'S, 70°14'W, Colombia'.

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.

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...

The broad dark stripe in the dorsal portion of the body extends into the ventral portion on the caudal peduncle, and this character can be used to distinguish it from the very similar-looking C. zygatus, with which it is often confused. In C. zygatus the dark stripe does not extend ventrally on the caudal peduncle and is present only on the dorsal part.

This species was formerly included in the genus Brochis alongside C. britskii and C. multiradiatus, and is sometimes referred to as 'common brochis'. Juveniles have a mottled colour pattern and are sometimes traded as 'hi-fin cory' due to their enlarged dorsal-fin. C. splendens can be told apart from other ex-Brochis species by possession of 10-12 dorsal-fin rays...

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.

This species spends almost all of its time at or just below the water surface, although it will sometimes retreat into midwater if threatened or feeding. Like other freshwater hatchetfishes, it is renowned for its ability to leap from the water surface and glide for distances of several metres. This behaviour is used both to catch flying insects, and to escape potential predators.

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.

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...

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...

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...

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...

Supposedly exported from the upper Amazon region in Peru but precise details are lacking. It's unclear whether this unidentified species is conspecific with the similarly nameless congener L266 or not.

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).

Type locality is given simply as 'Amazon River, Brazil' and according to current thinking this species has a huge natural range encompassing the Amazon River system in Brazil and Peru plus the Paraná-Paraguay drainage in southern Brazil and Paraguay and rio São Francisco basin in southern Brazil. Specimens in our images were collected fro...

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).

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 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...

This stunning miniature Loricariid has only been available in the hobby since 2001, and was described to science in 2004. As with other otos, it can be a little delicate when first imported and should be quarantined carefully until it's settled.

This is one of the commoner "otos" seen in the hobby, and is an ideal species for the planted aquarium. Unfortunately it can be quite delicate when first imported, and losses are not uncommon. This is usually down to lack of food, as it's a small fish and needs to feed almost constantly, so it's easily starved during transportation. As almost all otos are wild caught, they can be quite sensitive to water quality, too. Many hobbyists report fewer problems if the fish are added...

This species has had several L-numbers assigned to it, with L146 collected from an unspecified locality in Colombia and L232 from the Río Putomayo/Içá. It's exported for the aquarium trade under a number of different generic names including Hemiancistrus, Sophiancistrus and Peckoltichthys. Following Armbruster (2008) it can be to...

Quite widely distributed having been recorded from Brazil, Colombia, Peru and Venezuela. It's been collected from the upper parts of several major river drainages including the Río Negro, Río Orinoco (including the Río Inírida and Casiquiare canal) and Río Solimões. The type series was collected from 'Igarapé Préto', Brazil, said to be 60 kilometres to the south of the Colombian border city Leticia. Populations from Colombia and Brazil tend to be more intensely-coloured, and the Peruvian populations may apparently represent an undescribed species.

Famed as a rapacious predator capable of rapidly stripping flesh from bone and a danger to any animal entering its native waters, P. nattereri is among the most notorious freshwater fishes in the world. As a result, displays featuring this “bloodthirsty” creature are found in most public aquaria, grisly Hollywood movies have been released, and the species has become popular in the aquarium trade. Little of this infamy is based on factual evidence, however.

S. jurupari is also known as 'demon fish', 'jurupari earth eater', 'green horse face', or simply 'jurupari' in the aquarium hobby. It can be distinguished from other members of the genus by the following combination of characters: presence of a relatively small dark ocellus on the upper caudal-fin base; absence of well-defined dark blot...

T. stellatus is superficially similar to its only congener T. securis, but can immediately be identified by the presence (vs. absence) of a prominent dark spot in the dorsal-fin. It is sometimes traded as 'platinum hatchetfish'. The genus Thoracocharax was originally erected by Fowler in 1906 as a subgenus of Gasteropelecus, but was elevated to generic status by Weitzman (1960).

This species is not often available and is much sought after in the aquarium hobby where it's been traded as 'crystal rainbow tetra' and 'orange-tailed glass tetra'. It's also been referred to as a Heterocharax or Tyttocharax species in the past. It's currently the only member of its genus which is separated fr...

Wild swordtails are a fairly basic green colur. However the vast majority of swordtails available in the hobby today are hybrids of X.helleri with X.maculatus or X.variatus. There are a huge number of selectively-bred varieties available, including wagtail, lyretail, tuxedo, albino, neon, red, green and hi-fin. Swordtails may undergo what appears to be a change in sex. In young fish this may simply be late development. However some adult females develop male characteristics which is thought ...

The genus Acarichthys remains monotypic and was resdescribed by Kullander (1986) who characterised it by the following: lack of epibranchial lobe; comparatively few (12-14)rays; pelvic fins with relatively broad tips (branches of the first ray are equal in length or the inner is slightly longer); possession of a single supraneural plus 14-15 vertebrae (these characters taken as a combination); no caudal extensions to swim bladder; no caudal ribs. Its current taxonomic position is based largel...

This is the type species of the genus Aequidens and has the widest distribution of any member species. It exists in various colour forms depending on locality with variants from Ecuador and Peru being particularly sought after since they develop striking red (Ecuador) or orange (Peru) colouration on the lower part of the jaw, head and anterior portion of the belly whereas those from Brazil tend to have an overall grey/blue/green colouration, for example. Despite its type status it's long...

This species can be told apart from the very similar-looking congener B. filamentosum by its smaller adult size (B. filamentosum can grow to almost 3 m in length), shorter maxillary barbels (never extending beyond base of adipose fin (vs. extending beyond base of adipose fin), moderately-forked with lobes of equal size (vs. deeply-forked caudal fin with upper lobe usually longer than the lower) and body col...

In the Amazon region it is only specimens larger than around 160 cm and werighing in excess of 50 kg that are referred to as 'Piraíba' with the name 'filhote' normally applied to smaller individuals. Other vernacular names include 'Salton catfish', 'Kumakuma'; and 'tiger antenna catfish'; with members of the genus often referred to collectively as 'goliath catfishes'.

Brachyplatystoma spp. are distinguished from all other catfishes by two synapomorphies. The first comprises several morphological characters relating to the skull, specifically that the mandibular suspensorium (that which connects the lower jaw bone to the skull) is greatly expanded mediodorsally to form a large plate approaching the parasphenoid bone, with the hyomandibula and metapterygoid similarly enlarged.

Study of B. rousseauxii has revealed that sexually mature adults are found only in the western Amazon, with no mature individual ever recorded east of Manaus despite the intensive commercial fishery operating there. The total distance covered by some populations during migration from the delta was as much as 5500 km, making it the longest known in any freshwater fish species.

This rich feeding ground is exploited until the sea water returns, at which point the catfishes begin to migrate upstream in massive numbers, moving up the Amazon and its tributaries. Sexually mature individuals are not normally recorded during these events so they're thought related to feeding and dispersal rather than spawning. The fish are subject to intensive capture by commercial and artisanal fishing operations during this upstream movement.

This species can be confused with three similar-looking fishes of uncertain taxonomic status which have been assigned the C numbers C024, C077, and C109 in the aquarium hobby. C024 and C109 are unlikely to be conspecific in that they occur in Pará state, Brazil, several thousand kilometers outside the range of C. acutus, in the rio Guamá (Tocantins drainage), and lower rio Xingu, respectively.

This species' name is commonly misapplied to a number of similar-looking fishes and it can be difficult to identify if collection locality is unknown. In addition, colour pattern is variable and it's not clear whether this occurs between, within, or both between and within populations. In the original description, Steindachner did note that the first three dorsal-fin rays are completely black while the remainder is whi...

Described from the Río Ampiyacu, a small tributary draining into the main Amazon channel in Loreto Department, northeastern Peru, with additional records from the Yavarí (Javari), Napo, Nanay, and lower Ucayali drainage basins. All of these are Amazon tributaries, and C. ambiacus appears to occur in most or all affluents of the main Amazon channel between th...

This species is among the more popular Corydoras in the aquarium hobby and is widely available. It may also be referred to as 'arched cory'. There exist a number of similar-looking congeners, particularly C. urucu (Britto et al., 2009), described from the rio Urucu in Coari municipality, Amazonas state, Brazil, and C. narcissus from the rio Purus. The latter appears to have also been traded as C. sp. 'super arcuatus longnose' while a larg...

Fish collected in the upper rio Maderia basin in Brazil and Bolivia have been traded under the invented names C. sp. 'dorsalis' and C. sp. 'ogawae' in the past, although are officially-considered conspecific with C. armatus. This appears to warrant investigation since the Río Huallaga in Peru, type locality of C. armatus, and collection localities in the upper Madeira are separated by a straight-line distance of almost 2500 km.

This species is sometimes confused any of several similar-looking fishes such as C. sychri or C. sp. C097. While the former is a more elongate fish with a longer snout and quite easy to identify, C097 resembles C. atropersonatus more closely, despite being traded as C. sychri 'longnose'. Its snout is longer than that of C. atropersonatus but shorter than that of C. sychri, and the dark spots on the body tend to be more well-defined and spaced out than in the other two.

This species is popular in the aquarium hobby and unlike the majority of congeners tends to spend a fair amount of time away from the substrate, often forming groups in midwater. It has been placed in the unofficial 'C. elegans group', which contains a number of species exhibiting similarities in morphology and colour pattern, some of which remain unidentified in scientific terms.

There are currently over 180 described species of Corydoras (commonly shortened to "cory"), making it one of the most speciose of all South American fish genera. There are also loads of undescribed species, many of which have been assigned a "C number" for identification purposes. This is a very simple system of numbering and is similar to the L number scheme used to identify undescribed Loricariids. Both systems were implemented by the German aquarium magazine DATZ (Die Aqua...

This unidentified species was originally traded under the C-numbers C115 and C116 but these two are now thought to represent the same species, while fish collected from Manú National Park and sold as C. sp. 'Manu 1 long nose', C. sp. 'Manu 4', C. sp. 'Manu 7', and C. sp. 'Manu 8' may represent this species as well. It's highly variable in terms of colour patter...

This species is sometime referred to as 'Virginia's catfish', Corydoras sp. 'Sangama' or 'Zangama', and prior to description was misidentified as both Corydoras bicolor and C. delphax. Unfortunately additional 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.

Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market. Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

Given its eventual size and natural behaviour this species is largely unsuitable for the home aquarium, and we know of only a handful of private aquarists with the facilities required to house it long-term. Unfortunately juveniles are readily available in the trade, although the scarcity of privately-maintained adults would suggest that most fail to reach their potential.

R. vulpinus is the most widely-distributed member of the family Cynodontidae. Type locality is given simply as 'Brazilian rivers', but this species is currently understood to be distributed in the Amazon basin from the Río Ucayali system in Peru, eastward as far as the rio Xingu in Brazil, plus the rio Tocantins and Rio Capim basins. It's also known from the Río Orinoco ba...

An obligate predator feeding on other fishes in nature, but quality dried foods are normally accepted in captivity. It should also be offered meaty fare such as strips of white fish, live earthworms, shrimp, etc., for optimum health.

H. eschwartzae is told apart from other laterally-striped Hyphessobrycon species from the Madre de Dios watershed by the following characters: 4 simple anal-fin rays (vs. 3 in other species listed); 13-15 dentary teeth (vs. 5-11); 6 teeth in the internal premaxillary ro...