Cuyuni

The duck catfish, Ageneiosus ucayalensis, is an auchenipterid catfish described from Peru and recorded across the Amazon, Orinoco and Guianas. Body patterning apparently varies with locality, and fish from black water habitats, particularly on the Guiana Shield, tend to be darker. Growing to around 290 mm SL and capable of taking large prey, it is safe only with similarly sized catfishes or large pelagic characins, mostly a combination for public aquaria.

The striped headstander, Anostomus anostomus, is an anostomid from the Amazon and Orinoco river systems in Peru, Brazil, Venezuela and Guyana. It lives along rocky shores of fast-flowing rivers, grazing algae and small invertebrates from the rocks. Although it shoals in nature, it is very quarrelsome with conspecifics when only a few are kept, so it is best kept singly or in a group of 6 or more in a larger tank.

The Amazon puffer, Colomesus asellus, is a freshwater puffer found throughout much of the Amazon basin, with records north to Guyana and Venezuela. Also traded as the South American puffer or 'SAP', it is told from congeners by a transverse row of dermal flaps across the chin. It lives mostly in well-oxygenated river habitats, is intolerant of organic waste, and forms loose aggregations, so a group of 6 or more is best, away from the general community.

Geophagus brachybranchus is a cichlid from the Nickerie and Courantyne drainages of Suriname, also reported from Guyana and Venezuela. Generally rare in the aquarium hobby, it appears to be one of the commoner species in Australia, where it is often called the 'black-throated eartheater'. The largest wild specimen recorded measured 138 mm, but it is known to reach 180 to 200 mm in captivity.

The whitespot eartheater, Satanoperca leucosticta, is a cichlid from the Guiana Shield in Guyana, Suriname, eastern Venezuela and northern Brazil. Farmed in several countries, it is frequently available in the ornamental trade. It is often confused with S. jurupari but is easily recognised by the prominent white spots or vermiform markings on the sides of the head. A larvophilous maternal mouthbrooder, it has been bred in aquaria.

Boulengerella cuvieri is a pelagic ctenoluciid characin from much of the Amazon basin, the Río Orinoco and coastal drainages of the Guianas. The largest officially recorded specimen measured 675 mm, but it appears to grow larger, possibly beyond 800 mm. Given that size and its natural behaviour it is largely unsuitable for the home aquarium. Its entire dorsal-fin base lies ahead of the anal-fin origin, a character shared only with B. lucius and B. xyrekes among ctenoluciids.

The blackstripe cory, Hoplisoma bondi, long known as Corydoras bondi, is an armoured catfish from Venezuela, Guyana and Suriname, including the Essequibo and Courantyne systems. It was once considered common in the hobby, but many fish traded under the name may be the similar H. sipaliwini or H. coppenamense. H. sipaliwini has larger body spots and a dark marking on the first dorsal-fin rays, while H. coppenamense is more orangish.