The best known of the goodeids, Ameca caused a stir in the early 1970s when it was introduced into the hobby, largely because of its unusual reproductive strategy. Unlike in poeciliids, male goodeids do not have a gonopodium; instead, they have a distinct notch (a spermatopodium). Fertilization of eggs is internal, but the females cannot store sperm, so each brood requires separate insemination. After an egg has been fertilized within its egg sac, the female ejects it into the ovarian cavity, where development takes place. When the fry are born they are large and well developed. Although Ameca is under threat in the wild, the species itself is safe since all specimens currently in the hobby are captive bred.
Other common name
- Butterfly Goodeid
- Ameca River basin in Jalisco (Mexico).
- Males up to 3in (8cm); females up to 4 3/4in (12cm).
- Active, generally tolerant species; older specimens may develop into fin-nippers.
- All foods accepted; vegetable component is important.
- Spacious, well planted tank with some floating vegetation and some open swimming spaces. Alkaline, medium-hard water is preferred. Temperature range: 64-84 F (18-29C) tolerated, but 72-77 F (22-25 C) advisable in the long term.
- Up to 40 large fry can be produced during the warmer months of the year at around 8-week intervals.