River
Marañón
33 profiles across 13 families name the Marañón as a locality.
- Species
- 33
- Families
- 13
- Photographed
- 32 of 33
- Difficulty rated
- 33 of 33
Basin
Also in the Amazon basinspecies recorded from both
Shares fishes with rivers elsewherespecies recorded from both
Runs through

Agamyxis pectinifronsSpotted Talking Catfish
Doradidae · Cope, 1870
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...

Amblydoras nauticusMarbled Talking Catfish
Doradidae · Cope, 1874
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...

Apistogramma baenschiA188
Cichlidae · Römer, Hahn, Römer, Soares & Wöhler, 2004
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.

Apistogramma bitaeniataTwo-Striped Dwarf Cichlid
Cichlidae · Pellegrin, 1936
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.

Apistogramma cacatuoidesCockatoo Cichlid
Cichlidae · Hoedeman, 1951
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...

Astyanax bimaculatusTwo Spot Astyanax
Characidae · Linnaeus, 1758
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.

Boulengerella maculata
Ctenoluciidae · Valenciennes, 1850
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...

Brachyplatystoma tigrinumZebra Shovelnose
Pimelodidae · Britski, 1981
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...

Carnegiella myersiPygmy Hatchetfish
Gasteropelecidae · Fernandez-Yepes, 1950
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...

Carnegiella strigataMarbled Hatchetfish
Gasteropelecidae · Günther, 1864
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...

Colomesus asellusAmazon Puffer
Tetraodontidae · Müller & Troschel, 1849
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.

Copeina guttataRed-spotted Tetra
Lebiasinidae · Steindachner, 1876
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.

Copella nattereri
Lebiasinidae · Steindachner, 1876
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.

Corydoras copei
Callichthyidae · Nijssen & Isbrücker, 1986
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.

Corydoras lambertiC009
Callichthyidae · Nijssen & Isbrücker, 1986
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.

Corydoras pastazensisPastaza Cory
Callichthyidae · Weitzman, 1963
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...

Corydoras zygatusBlack Band Cory
Callichthyidae · Eigenmann & Allen, 1942
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...

Cynodon gibbus
Cynodontidae · Agassiz, 1829
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.

Hyphessobrycon erythrostigmaBleeding Heart Tetra
Characidae · Fowler, 1943
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...

Hyphessobrycon loretoensisLoreto Tetra
Characidae · Ladiges, 1938
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...

Hyphessobrycon peruvianusPeruvian Tetra
Characidae · Ladiges, 1938
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...

Lamontichthys filamentosusSturgeon Catfish
Loricariidae · La Monte, 1935
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).

Leporinus fasciatusBanded Leporinus
Anostomidae · Bloch, 1794
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.

Nannostomus rubrocaudatusPurple Pencilfish
Lebiasinidae · Zarske, 2009
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...

Nannostomus trifasciatusThree-lined Pencilfish
Lebiasinidae · Steindachner, 1876
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...
Otocinclus cocamaZebra Oto
Loricariidae · Reis, 2004
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.

Peckoltia bachiL146
Loricariidae · Boulenger, 1898
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...

Satanoperca jurupariDemon Eartheater
Cichlidae · Heckel, 1840
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...

Thoracocharax stellatusSpotfin Hatchetfish
Gasteropelecidae · Kner, 1858
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).

Corydoras acutusBlacktop Cory
Callichthyidae · Cope, 1872
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.

Corydoras armatus
Callichthyidae · Günther, 1868
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.

Osteoglossum bicirrhosumSilver Arowana
Osteoglossidae · Cuvier, 1829
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.

Aguarunichthys torosusBolt Catfish
Pimelodidae · Stewart, 1986
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.