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…

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.

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…

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…

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…

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…

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.

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.

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.

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…