Scientific name: Ameca splendens
Common name: butterfly
goodeid
Red list status: EXTINCT IN THE WILD, fairly secure in captivity
pH: 6.5-8, neutral or higher preferred, water should be hard.
Temperature: 74-80 F
Diet:
Omnivores who must have adequate plant matter in their diet.
Reproductive method:
live birth
Gestation: 55-62 days
Litter size: 3-30, 5-18 is more common as fry are extremely large.
Maximum size: 4.5 inches female, 3.5 male
Markings: Silver and brown fish with black spots. Males develop metallic colors along the sides and a vivid yellow crescent on the tip of their tail.
Behavior: Amecas are one of the easiest and heartiest of the goodeids. They like much warmer water than most of their relatives, and are more tolerant of less-than-perfect water. Although they are large, they are good natured and do not harass tankmates. They are entirely suitable for a community tank over 20 gallons.
While no parental care is practiced, amecas are not prone to cannibalizing their own fry like many livebearers do. Fry are born with a trophotaenia attached—essentially a primitive umbilical cord—and do receive nourishment from the mother while gestating. The cord remains for about 24 hours, then drops off. Fry are surprisingly large for livebearers, easily a quarter inch and occasionally a half inch at birth.
Sources:
fishbase.org
goodeids.com
personal experience with the species