About the Butterfly Goodeid
Species Type: Freshwater Fish
Care Level: Easy. Does well in a slightly more narrow range of water parameters and shouldn't be used to cycle an aquarium. Will eat most prepared foods. May have some specific care requirements in terms of particular water parameters, social behaviors, food items etc.
Origin: Rio Ameca and Rio Teuchitlan, east of Ameca, Jalisco, Mexico (extinct in the wild)
Compatibility/Temperament: Not a good community fish as it can be quite aggressive, particularly the males. It's also very competitive at feeding time. It can be maintained in a community of similarly sized, robust species but is better kept in a species setup.
An easily-bred live bearer. A species tank works best, and it can be bred using a single pair or a group (this is known as flock spawning). The breeding tank should be planted very heavily. Goodeids breed in a slightly different way to other livebearers, as females don't store sperm as in many other livebearing species, and must be fertilised separately for each brood of young. They also display no gravid spot.
The female initiates mating by swimming diagonally in front of the male and performing quivering movements. This increases in intensity and the male exhibits his strongest colouration before joining in the courtship. Eventually the fish come together and mating occurs.
Gestation takes between 55-60 days after which 5-30 huge (up to 0.75"!) fry are produced. Sometimes these may have what appears to be an umbilical cord attached. This is quite normal (see below) and will disappear in 2-3 days. The fry are large enough to accept the same foods as the adults from birth and will be bold and outgoing from the outset, competing for food with any other fish in the aquarium. The parents rarely predate on the fry.
This monotypic species is unfortunately now limited to a single population in nature and is already classed as extinct by many sources. Despite this it's not particularly scarce in the hobby as strong captive bred populations now exist, some of which have been selectively bred to produce variations in colour and patterning.
As with other goodeids, there is less of a size difference between the sexes than in many other livebearers. This is thought to be related to the relatively primitive structure of the andropodium, as the fish tend to choose mates that are of similar size so that the sex organs are synchronised.
Goodeids are unique among livebearers in that the developing young are nourished by a specialised structure known as the trophotaenia. This performs a similar function to the placenta in mammals and the remnants of it can often be seen attached to the young fish at birth. Male fish also possess an internal muscular structure known as a pseudophallus, which connects the sperm ducts to the genital opening. This is thought to forcibly eject sperm.
In the aquarium, male fish develop a pecking order amongst themselves which involves a great deal of displaying and some nippng, but lasting physical damage is rare. The alpha male in any given group can be identified by his brighter colouration and more vigorous nature.
Butterfly Goodeid Diet
An omnivorous and greedy feeder, it will accept most foods offered. It does consume large amounts of algae in the natural habitat so some greenstuffs should be included in the diet. Blanched spinach, nori (dried seaweed) and Spirulina flake all work well.
Male 3.2" (8cm). Female 4.8" (12cm)
Minimum Tank Suggestion
Ideal water parameters for Butterfly Goodeid
Temperature 70-77F. pH range 7.0 to 8.0, Hardness 10-20 dGH.