Ameca splendens Male

Meaning of Name

Genus- Ameca= named after the river it is from, The Rio Ameca.
Species- splendens= shinning (Latin).


Ameca splendens is a pretty livebearer from Mexico and one that is on the verge of extinction. Only one population of this fish remains in the wild and it is in the middle of an amusement park in Mexico. Because of this, the Butterfly Goodeid is commonly bred in species maintenence programs. This pretty goodeid is a peaceful and welcome aquarium resident that offers to add a little brightness as well. Although females are generally an olive and black mottled fish, males develop very yellow fins, giving them the common name the Butterfly Goodeid.


The Butterfly Goodeid is native to the Rio Ameca and its tributaries in Mexico.

Size, Maturity, and Sexual Dimorphism


Males- 4 inches, Females- 3 inches


2.5 inches

Sexual Dimorphism

Males are smaller than females and have a yellow edge to the caudal fin. Males also possess an andropodium, which is a modified anal fin for reproduction. Look for the notch in the male’s anal fin.


Butterfly Goodeids present few problems. Although some people would say they are aggressive, I'd disagree. They can be nippy and chase each other, but seldom cause any damage. I think it is best to keep this species in a large group of eight or more individuals. They can be mixed with other fish and mix well with Central American cichlids.


Butterfly Goodeids are omnivorous and will eat anything in aquarium. They predominantly feed on vegetable matter in the wild. A quality spirulina or vegetable-based flake would be beneficial to its diet.


We obtained six Ameca spelndens from the 2007 ALA Convention. We were lucky to get ours from Pat Hartman which were labeled "Ameca splendens M66-17 Rio Teuchitlan, Mexixo, Descendants of the original collections by Dr. Robert Rush Miller, 1966". To think that these fish have been kept as a pure line for for close to fifty years . . .

Butterfly Goodeids breed like most goodeids. This species has a very long gestation period of nearly two months! It's important to note that goodeids don't store sperm like other livebearers and need to spawn for each brood.

The fry are huge when born, about .75 inches long! Spawns can range from 5-25 per brood. Larger females have larger spawns. The fry hang at the top of the tank for their first week out of the womb. Although adults seldom give chase to the large babies, it is a good idea to provide some cover such as floating plants.

The fry are very easy to raise and will feed right away on crushed flake. I prefer to use baby brine shrimp to raise them. The fry grow quickly and look just like females in terms of coloration.

At about 1.25 to 1.5 inches, males will develop the yellow edge to their caudal fin.


Ameca splendens was once a very popular fish in the aquarium trade. Recently, that has changed. It is still available from hobbyists and is inexpensive. Why it isn't more popular is a mystery as it is a very attractive fish that is not demanding.

I kept Ameca splendens from an unknown collecting location about 20 years ago and it seemed to me that the yellow caudal edge was much brighter in the specimens I had at that time . . . almost a canary yellow. Males from the location referenced above have more of a creamy yellow edge to the caudal. It would be interesting to hear from other hobbyists who have Ameca splendens with brighter tails.


  • IUCN. IUCN Red List of Threatened Species.>.
  • Miller, R.R., Fitzsimons, J.M., (1971) Ameca splendens, a new genus and species of goodeid fish from western Mexico, with remarks on
    the classification of the Goodeidae. Copeia 1971 (1), 1–13.
  • Miller, R.R., Minckley, W.L. & Norris, S.M. (2005) Freshwater Fishes of México. Museum of Zoology, University of Michigan, & University of Chicago Press, Chicago, 652 pp.

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Ameca splendens Female

Ameca splendens Fry