Ameca splendens

Ameca splendens, commonly known as the Butterfly Goodeid, was once declared extinct in the wild but is now maintained through an extensive international captive breeding network. Males are distinctive for the bright yellow or white edging on the caudal fin — the 'butterfly' colouration from which the common name derives — combined with iridescent blue-green flanks and a robust, silver-grey body.

This species displays fascinating social behaviour, with males establishing dominance hierarchies and performing elaborate courtship displays. It is one of the larger goodeid species and requires a spacious tank with excellent filtration. Males can be mildly aggressive towards each other during hierarchy establishment but are generally peaceful towards other species.

Ameca splendens has been kept in captivity for over 50 years and is one of the best-studied goodeid species. It is an excellent ambassador species for goodeid conservation and a rewarding, long-lived aquarium fish for the dedicated hobbyist.

Water: 18–26 °C, pH 7.0–8.0, GH 8–20; tolerates a wider temperature range than many goodeids. Tank: 120 L minimum; robust plants; good filtration; males establish territories — provide line-of-sight breaks. Feeding: Quality flake, spirulina wafers, blanched vegetables, frozen Artemia; varied diet essential. Breeding: Goodeid; gestation 60–65 days; 5–30 fry per litter; remove fry for grow-out. Compatibility: Peaceful towards other species; males mildly competitive; avoid very small fish.