This species is something of an "ugly duckling", as it's usually sold as a fairly bland looking, silvery juvenile. Given time and a good diet it develops into a magnificent fish as an adult, that really does sparkle like a diamond. A big shoal of these in a planted tank looks stunning.

The taxonomic status of all species in the genus Moenkhausia is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for a large number of small ch…

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…

This small species is a popular aquarium fish but there is some confusion surrounding its identity. Two colour forms have been traded, one of which also possesses tiny hooks on the fin rays.

It can be distinguished from congeners by colour pattern; the body is rose-coloured, fins red with no black markings, and the ovoid humeral spot is prominent, measuring around half of the body depth.

The majority of records pertain to the rio Guaporé (Río Iténez in Bolivia), the main affluent of the rio Mamoré, which drains the vast tropical wetland known as the Pantanal, and the upper rio Paraguai, which also has its headwaters in the Pantanal but flows in the opposite direction. The Guaporé and Paraguai are connected due to rising water levels during the annual wet season.

Care must be taken when purchasing this species as females look so different to males that the sexes were initially described as separate species!

A charming little cichlid with real character, L. ocellatus is a deservedly popular hobbyists' fish. It has an endearing habit of burying its shell and defending it against all-comers. Many an unsuspecting hobbyist has recieved a sharp nip from an ocellatus who feels its territory is being invaded. Neighbouring shells may also be buried to prevent other fish moving in. Koning has hypothesisesd that the burying of the shell and the resultant pile of sand around it not only provides additiona…

A highly piscivorous, predatory species unsuited to the general aquarium. It is an ambush predator in nature, often being seen hanging motionless around rocky structures or on the floor of the lake. It is a sedentary species and does not move around a lot. This is a behavioural adaptation known as thanatosis, or 'playing dead'. This strategy is usually used as a defensive means in other animals, but in L. lemairii it is adapted for offensive means. The fish has a mottled colour pattern…

L. kungweensis can be distinguished from similar species such as L. hecqui by the gold colour on the top of the eye. It also has a distinctive black spot towards the back of the dorsal fin.

It is not often seen in the hobby….

An interesting species which resembles the popular Steatocranus species, both physically and in lifestyle. It has several physiological adaptations to allow it to live in rapids and fast-moving waters. The body is very streamlined, with strong pectoral fins. The swimbladder is also modified, being much reduced in size. This makes the fish less buoyant and thus less likely to be swept away by strong currents. In the aquarium it spends most of its time on the substrate, where it swims in a comical…

This pretty little species can be seen for sale with various common names, including the 'blue emperor', 'regal' or 'royal' tetra. It's sometimes confused with the emperor tetra, Nematobrycon palmeri but can be easily distinguished as it possesses an adipose fin, whilst Nematobrycon species do not.

The genus Inpaichthys is currently monotypic (contains only one species), and like other related genera such as Hyphessobrycon its taxonomic status is Incertae s…