A biotope-style set-up could consist of a sandy substrate, piles of smooth rocks and driftwood roots and branches, some of which should penetrate the water surface.

Aquatic vegetation can be included if you wish but is likely to be eaten.

This species is widely-distributed in the Río Orinoco system in Brazil, Colombia and Venezuela plus coastal drainages in Guyana, Suriname and French Guiana including the Essequibo and Mazaruni.

Type locality is ‘Palital, Estado Guárico, Venezuela’ which appears to correspond to a wetland called Esteros de Palital in the Aguaro-Guariquito National Park of Guárico state, northern Venezuela.

This species is rare in the hobby although other species are sometimes sold under the name. It’s a member of the nominal G. surinamensis ‘group’ of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; four parallel, ventrally-inclined bars on each flank (normally visible only when the fish are stressed, spawning or preserved); dark lateral spot positioned within the second vertical bar; caudal fin red with variable pattern of large, iridescent blue to white spo…

This species can be told apart from relatives by the characteristic ‘keyhole’ shaped marking on each side of the body.

It’s one of few fishes in which the current generic name is derived from the common name popularised in the aquarium hobby with ‘Cleithracara‘ a combination of the Greek kleithron, meaning lock, and, acará, the Guaraní word for cichlids.

The eye of Anableps species is split horizontally by a band of epithelial tissue. It has two corneas, two pupils, a single, egg-shaped lens and one retina that's also split into two sections. The lens is oval and asymmetric with the upper part flattened as in the human eye and the lower section curved as in most other fishes. The upper cornea is thicker and enriched with glycogen which possibly helps to protect it from drying and UV irradiation. Two horizontal flaps of the iris are thought …

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…

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’.

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.

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.

This species occasionally appears in the ornamental trade where it is sometimes referred to as ‘blue tiger piranha’

Following Fink and Macaht can be distinguished from other members of the genus by the following combination of characters: body shape deep and rhomboid; head robust, snout blunt; eye large; mouth moderate, jaw projecting; 1-3 ontogeneticlly var…