Colombia

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...

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, 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 The grouping remains poorly-studied with the last major revision having been conducted by Watson (1990) in his unpublished dissertation, in which A. inermis was included under the currently synonymous name A. brevifilis.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 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.

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.

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 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.

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.

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. Member species have also been organised into a series of species lineages, complexes and groups by authors in order to better separate them.

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...

This undescribed species was first collected and subsequently appeared in the aquarium hobby during 2008. It was exported again in late 2009 and early 2010 under the names A. sp. 'Jutai' and A. sp. 'diamond face', and said to have been collected in the Río Jutai, Amazonas state, Brazil. The Jutai is a south bank tributary of the Solimões but lies several hundred kilometres downstream of Leticia so this information, from a purportedly trustworthy source, initiall...

Apistogramma viejita

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.

This species is much rare in the hobby than its congener A. stigmatias, presumably a reflection of its more remote, restricted natural range. The red pigmentation on the body can vary in both extent and intensity, and apparently begins to fade when the fish have been maintained in aquaria for a period.

Prior to description this species was traded under the DATZ code L239. It can be distinguished from other species in the genus and other hypostomines (see below for definition of this grouping) by its uniformly black to brownish body and fin colouration with a turquoise to bluish sheen, and the acutely bent shape of midventral body plates 3-5 which form a distinctive keel running along the body, above the pectoral fins...

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.

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...

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...

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...

This species is traded under a number of English vernacular names, of which some others include 'blonde bulldog pleco', 'blonde rubber pleco', 'blonde rubbernose pleco', 'striped rubber pleco', and 'striped rubbernose pleco'. It may also be seen referred to as 'L146', 'L146a', or 'L187b', these codes having been used for it in the Aqualog series of books. It can be told apart from all congeners except C. anale and C. jegui by...

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.

Although it does penetrate the lower basins of rivers, particularly the Amazon where it has been collected from the rio Xingu several hundred kilometres from its mouth, this species is predominantly an inhabitant of mangrove swamps, estuaries, and other such saline habitats. It is particularly common in tidal channels, shallow inshore lagoons, and the lower reaches of rivers.

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 does appear in the aquarium trade from time-to-time, often among shipments of other wild-caught fishes from the Orinoco basin. Populations from Colombia were formerly referred to as C. metae until Zarske (2011) synonymised the two when designating a lectoty...

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...

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'.

The majority of records derive from the Río Apure watershed in southwestern Venezuela, where C. habrosus has been collected in the states of Portuguesa, Cojedes, Barinas, Guárico, and Apure. Its distribution in Colombia is less clear but it is known with certainty from the Río Arauca and Río Casanare, the latter a tributary of the lower Río Meta, and it makes sense that it should also be found in other left bank Orinoco affluents between the Meta and Apure, which include the ríos Cinaruco and Capanaparo.

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.

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.

Endemic to the Río Meta, a major tributary of the Río Orinoco in eastern Colombia and western Venezuela. It is known from several tributaries within the upper basin including the ríos Humea, Ocoa, Guatiquía (including its two branches the ríos Negrito and Guayuriba), Manacacias, and Metica (the name given to the upper Río Meta above its confluence with the Río Humea). It appears to be absent from the lower Meta and has not been recorded in Venezuela.

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...

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.

C. hujeta is traded under various names including 'slant-nosed gar', 'hujeta gar', 'rocket gar' and 'freshwater barracuda' but it and other members of the family Ctenoluciidae have traditionally been referred to as 'pike characids'. They're all predatory fishes native to South America, included in the order Characiformes and currently spread across two genera; Ctenolucius with two species and Boulengerella with five. The two genera are ...

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.

Although often sold as the closely related F. acus (a species that is highly endangered and imported very rarely, if at all), F. vittata is the most common representative of the genus in hobbyists' tanks. The easiest way to distinguish the two is by comparing the shape of the rostrum, which is longer and more slender in vittata, although there are also differences in the arrangement of the ventral scutes. They are adapted for life among peripheral vegetation and tree roots along the edges o...

This species appears to be a relative ecological generalist. During a sampling trip in 1989 it was collected various habitat-types including a narrow (maximum width 3 m) stream containing shallow (maximum depth 1 m), transparent, moderate to fast-flowing water and substrate comprising gravel, mud, clay and organic debris including submerged logs. Aquatic plants consisted of water lilies and marginal vegetation was dense, comprising various trees, shrubs, grasses and ferns.

This species lends its name to the 'G.' steindachneri, an assemblage of closely-related species with unresolved generic placement which currently also includes 'G.' crassilabris and 'G.' pellegrini. It exists in a number of colour forms which vary with locality, some of which may eventually be described as separate taxa. Some of these may appear on trade lists under the synonym Geophagus hondae.

This species is also traded as 'blue flame', 'blue-red', and 'Colombian red fin' tetra, and was misidentified as H. ecuadorensis for several years prior to its description. Within the genus it appears to be most closely related to the Costa Rica endemic H. savagei Bussing, 1967 but differs in a number of characters as fol...

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...

A beautiful species that's not often seen for sale in the hobby, and is usually a little more expensive than other tetras when available. This is mainly due to the wild caught nature of most specimens entering the trade. It can be a little delicate when initially imported, and is sensitive to deteriorating water conditions in general. As a result, it's not a good choice for the beginner, and should only be added to well-matured tanks. As with the closely related Hemigrammus, the ta...

At least two colour forms have been traded, one of which is more intensely-coloured and has been referred to as H. sweglesi 'red' or 'rubra'. The bright red pigmentation is retained in long-term captive specimens, suggesting that it is not considered to be an artefact of diet, but we suspect it might reflect conditions at the collection locality with the reddest fish putatively inhabiting blackwater and plainer forms clearwater environments. Zarske (2014) found the two forms to be identical in terms of morphology an...

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'.

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...

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

M. ramirezi is also known by the names 'Ramirez' dwarf cichlid' and 'butterfly cichlid' and is among the more popular dwarf cichlids in the aquarium hobby. As a result, it is produced on a commercial basis in huge numbers and a number of ornamental strains have been developed including 'gold', 'long-finned' (both blue and gold forms; also traded as 'lyre-tail', 'veil-tail' and 'hi-fin'), 'electric/neon blue', 'super neon blue gold' 'pearl/perlmutt' and 'balloon'.

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...

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 species has been referred to the genera Poecilobrycon and Nannobrycon in the past and in the aquarium hobby is also known as 'oneline' or 'red fin' pencilfish. It's a popular aquarium fish and has an interesting oblique swimming-style, a behavioural trait shared only with N. eques among congeners. The most recent diagnosis of the species appears to be that giv...

Type locality is the Río Calima in Valle del Cauca department, western Colombia. The Calima is a major tributary within the Río San Juan system and N. lacortei is considered endemic to this drainage.

This species can be found in most dealers' tanks and is one of the best choices for the newcomer to fishkeeping, being attractive, hardy and inexpensive. As virtually all the fish sold in the trade have been captive bred they tend to be relatively unfussy regarding water chemistry and diet. It's occasionally confused with N. lacortei, which is currently the only other species in the genus. They can easily be told apart by looking at the eye of the fish in question, as the male N. l...

Endemic to the Río Atrato drainage in Choco and Antioquia departments, northwestern Colombia, where the full extent of its range is somewhat unclear. Type locality is 'Río Truandó, a tributary of Lower Río Atrato, Colombia', and it may be restricted to that system.

It was initially going to be described as Hyphessobrycon cardinalis by Myers and Weitzman (1956) but just before this was due to be published Schultz presented an alternative description in the hobbyist magazine 'Tropical Fish Hobbyist' and named the fish after the publication's founder, Dr. Herbert R. Axelrod. A significant proportion of the fish available in the aquarium trade are still wild caught or derive from community-led breeding projects such as Project Piaba in the middle Negro region, where this sp...

For aquarists perhaps more useful are the subtle differences in colour pattern with P. simulans differing from both P. innesi and P. axelrodi in possessing a greener (vs. bluer) lateral stripe which covers more (vs. less) of the eye/head and extends to the caudal-fin base (vs. terminating anterior to caudal-fin base), a lesser (vs. greater) amount of relatively duller (vs. brighter) red pigmentation on the flanks. The taxonomic history of all three species is complicated with earlier authors such as Géry (1960, 1977) ten...

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...

Known with certainty from tributaries of the middle Río Orinoco between the city of Puerto Ayacucho, Amazonas state, Venezuela and the lower Río Meta, Colombia. It may have a wider distribution within the Meta system since some reports suggest it to occur around Villavicencia, Colombia, some 600 km upriver.

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.

Has been recorded from major river channels, smaller tributaries, and floodplain lakes, many of which comprise acidic, mineral-poor blackwater environments with brownish, tannin-stained water, although it has been observed to inhabit clear waters as well. Many of its habitats lie within the Venezuelan and Colombian llanos, a vast, highly biodiverse system of tropical savannah grasslands, seasonally-flooded plains and forests covering an area measuring almost 600,000 square kilo...

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. daemon is relatively common in the aquarium trade but is by no means easy to maintain, with particular attention to space, diet, water quality, and chemistry required in order for it to thrive. It can be distinguished from other members of the genus by possessing two dark blotches on the flank and a prominent ocellus at the caudal-fin base. Among the named species it is most similar to...

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).

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...

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.

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...

This species can be identified from similar-looking congeners by possession of a pair of small rictal barbels. Its colour pattern can vary considerably depending on collection locality, with some forms having been misidentified as other species in the past. Those possessing a dark marking on the sides of the body are sometimes referred to as Corydoras sp. 'olga'.

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.

Vernacular names in Brazil include 'Cachorra' or 'Pirandirá', although these are also applied to congeners. It can be told apart from all congeners by the following combination of characters: head and body silvery with dark dorsal surface; an elongate dark blotch posterior to the opercle; dorsal, caudal and anal-fin rays reddish to orange proximally with some individual variation in intensity and tonality; adipose fin dark, with diffuse black pigmentation.

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.

It differs from H. paucilepis by possessing 30-31 scales in the lateral row (vs. 28-29), 3 scales between the lateral line and anal-fin (vs. 4), 10 predorsal scales (vs. 9), ii, 9 dorsal-fin rays (vs. iii, 8), 4 maxillary teeth (vs. 1), and the distance between the dorsal-fi...

Pseudopimelodus bufonius