Corydoras

The blacktop cory, Corydoras acutus, is an armoured catfish from the upper Amazon basin in Brazil, Peru, Ecuador and possibly Bolivia. It can be confused with three similar fishes known as C024, C077 and C109. C024 and C109 occur thousands of kilometres outside its range, but C077 lives alongside it in the rio Abunã and is only known to differ in growing smaller. Some specimens lack the dark marking in the dorsal fin.

Corydoras aurofrenatus is an armoured catfish from the Río Paraguay-Paraná system in Paraguay, also recorded in Argentina and Bolivia. It has been traded as C. sp. 'Corrientes' and CW005. Each flank carries two dark blotches, one behind the head and one below the adipose fin, and the caudal-fin lobes are long with the upper more extended. C. ellisae has been treated as a junior synonym, although this appears not to have achieved wide acceptance.

Fowler's cory, Corydoras fowleri, is a long-snouted armoured catfish from the Amazon basin in Peru. Also known as the 'huanta cory' and 'milegros cory', it is often confused with C. coriatae and C. semiaquilus, and aquarium fish are regularly misidentified. Most long-snouted cories grow larger and are more aggressive than other Corydoras, and this one is suitable only for larger community aquaria.

The long-nosed skunk cory, Corydoras narcissus, is an armoured catfish that appears to be endemic to the Rio Purus in Brazil. It lives alongside Brochis arcuata and looks very similar at first glance, but has an elongated snout where that of B. arcuata is much more rounded. Large for a Corydoras at around 75 mm SL, it does best with some water flow in the tank.

The long-nosed smudge spot cory, Corydoras ourastigma, is an armoured catfish from the Rio Purus basin in Brazil. It can be confused with Gastrodermus guapore, Hoplisoma caudimaculatum, H. simile and Brochis spectabilis, but is the only one with an obvious long snout. Its smudged caudal blotch resembles that of H. simile but is grey to black. Nothing is recorded of its habitat.

The Pastaza cory, Corydoras pastazensis, is an armoured catfish from the upper Río Pastaza basin in Ecuador and the ríos Ucayali and Puinahua in Peru. The Río Tigre form was raised to species status as C. orcesi, a decision not followed by all authorities. The two are relatively easy to tell apart: in C. pastazensis the dark vertical bar breaks up or tapers off low on the body, and the body is peppered with numerous small dark spots.

The Peru black cory, Corydoras semiaquilis, is a long-nosed armoured catfish from the western Amazon basin in Peru and Brazil. A few colour forms are available in the trade, sometimes under invalid names such as C. 'huanta' or C. 'milagros'. Males can be somewhat aggressive towards one another, although with sufficient space no real damage should occur, and a group of at least six is best.

The northern longnose cory, Corydoras septentrionalis, is an armoured catfish from the Rio Orinoco in Venezuela and possibly Colombia. It superficially resembles C. simulatus and C. amapaensis. C. amapaensis has a clear caudal fin, where this species has a noticeably barred one. It is found in main river channels and tributaries.

Corydoras simulatus is an armoured catfish known only from the upper Meta watershed in Colombia. It can be identified from most similar-looking congeners by its pair of small rictal barbels. The colour pattern varies considerably with collection locality and some forms have been misidentified as other species, while fish with a dark marking on the sides are sometimes referred to as Corydoras sp. 'olga'.

C115 is an unidentified armoured catfish from the upper Río Madre de Dios in southern Peru, between Manú National Park and Puerto Maldonado. It was traded as both C115 and C116, now thought to be the same species, and fish sold as C. sp. 'Manu' variants may belong here too. It grows to around 70 mm SL and is highly variable in colour pattern, particularly in the extent of dark pigmentation on the front of the body.