This species is euryhaline and mostly inhabits brackish estuaries, coastal lagoons and the lower reaches of rivers.

It also occurs in freshwater habitats, however, including a number of inland lakes in Sri Lanka although it appears to have been introduced intentionally.

The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition many species exist in two or more geographical colour forms which may or may not turn out to be distinct in the future. Hobbyists tend to label these with collection data if available in order to avoid mixing them and the potential of hybridisation.

Member species have also been organised into a series of species lineages, complexes and groups by authors in order to better separate them.

The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition many species exist in two or more geographical colour forms which may or may not turn out to be distinct in the future. Hobbyists tend to label these with collection data if available in order to avoid mixing them and the potential of hybridisation.

Member species have also been organised into a series of species lineages, complexes and groups by authors in order to better separate them. Such lists have been augmented by fish that have appeared in the aquarium trade and are in a state of near-constant flux

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade. It has also been assigned the ‘A’ number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A103, A104, and A105 depending on locality.

Numerous ornamental forms of this species have been selectively line-bred for the aquarium trade, vernacular names for which include "sunset", "sunburst", "double red", "triple red", "gold", "white gold", "orange flash" and "albino". It has also been assigned the 'A' number A200 under the DATZ system with possibly conspecific, related forms similarly numbered A201, A202 and A203 depending on locality.

Th…

The genus Acarichthys remains monotypic and was resdescribed by Kullander (1986) who characterised it by the following: lack of epibranchial lobe; comparatively few (12-14)rays; pelvic fins with relatively broad tips (branches of the first ray are equal in length or the inner is slightly longer); possession of a single supraneural plus 14-15 vertebrae (these characters taken as a combination); no caudal extensions to swim bladder; no caudal ribs.

Its current taxonomic position is based largel…

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’.

Previously included as a member of the genus Cichlasoma, the midas cichlid is often confused with the red devil, A. labiatus. The two can be distinguished through differences in morphology. As suggested by its scientific name, A. labiatus often possesses characteristically large lips, although this is variable and should not be used as a defining indicator of species. More reliable differences include the bigger nuchal hump and more thick-set appearance in A. citrinellus.

The midas exists in many n…

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade, some of which include. It has also been assigned the 'A' number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A235, A236, A237, A238, A239, A240, A241 and A242 depending on locality.

The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition …

This species lends its name to the ‘G.‘ steindachneri, an assemblage of closely-related species with unresolved generic placement which currently also includes ‘G.‘ crassilabris and ‘G.‘ pellegrini. It exists in a number of colour forms which vary with locality, some of which may eventually be described as separate taxa. Some of these may appear on trade lists under the synonym Geophagus hondae.