Cyprinodontiformes vivíparos e ovovivíparos

Livebearer Cyprinodontiformes

Espécies > Ficha da espécie > Ameca splendens

Species > Species profile > Ameca splendens

















Ameca splendens  Miller & Fitzsimmons, 1971

Ameca splendens
Gartner, 1981

Ameca [ Português ]

Mexalpique Mariposa [ Español ]

Butterfly Splitfin [ English ]

Butterfly Goodeid [ English ]

Geographical distribution :

Mexico ( Teuchitlan River and Ameca River, Jalisco State ).

Introductions :

United States of America.

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I - Morphology Synopsis ( some meristic characters )

Total absolute lenght

Adult male : 67 to 85 mm

Adult female : 95 to 119 mm

Dorsal fin rays : / 13 ( 14 )

Caudal fin rays : / 20 ( 22 )

Scales on lateral line : 36 ( 38 )

Head lenght body lenght ratio ( male ) : 0,25

Head lenght body lenght ratio ( female ) : 0,23

You can find more pictures about these species availabe at the photo gallery.

II - Habitat and Geographical distribution

Ameca splendens it’s endemic from a hydrographical basin on west Mexico inside old territories of the ancient Aztec civilization.

At the time of its discovery the species was already confined to only some fragments of the what’s supposed to been the original geographical distribution, on the Ameca river basin and manly at 10 kilometres East of the city that inherited the name of the river.

Another typical localization it’s the Teuchitlán River, more precisely, near the place with the same designation.

Ameca means current of water or river on the náhuatl language. The municipality it’s placed at about 1.235 meters of altitude.

The local climate is considered half-dry, characterised by moderate winters and autumns without precipitation. The major rainfall takes place between June and September.

The mean annual temperature it’s 21.3ºC ( 70,34ºF ), with precipitation near 864 millimetres.

Besides that, the medium number of days with negative temperatures it’s around 10,9.

The Ameca river receives from North the tributaries El Cajón, Los Llanitos, La Barranca, La Arena, El Carrizo, Las Bolas, among others, while from South receives the waters of El Magistral, Arroyo Grande, El Zoquite, El Palmarejo, El Alamo, Las Canoas and some minor water flows.

There are now four dams : San Ignacio, La Vega, Los Pocitos and Texcalame.

Teuchitlán comes from Teotzitlán. That word means “ sacred place “, “ place of the God Tenoch “ or “ place dedicated to the God reverenced “.

In the proximity of the Ameca community, the climate it’s almost the same.

The medium annual temperature rages 21ºC ( 69,8ºF ), but the medium yearly precipitation reaches 1.008 mm and the number of days with negative temperatures is near 9,8 there.

The Teuchitlán River belongs to the Pacific hydrographical basin and to the Ameca River hydrographical sub-basin. His principal tributary it’s the Salado River as well as the Chapulimita, Los Otates and El Agüilote Rivulets. La Vega and La Lobera dams also reprise Salado River.

The original natural environment of the Ameca splendens it’s a lotic type.

It originally had clear waters and variable currents, where considerable fish groups of this species searched for sanctuary zones of backwater, between dispersed bunches of Ceratophyllum spp and Eichhornia spp.

The water temperature varies on average between the 13ºC ( 55,4ºF ) and the 29ºC ( 84,2ºF ) but these values can be slightly increased or decreased by less common meteorological conditions.

The bottom it's sandy in general, but there are many stones, with occasionally rocky flourishing at surface.

There are confirmed reports of the species introduction in the United States of America ( Colorado River – State of Nevada ), where it’s possible to find established populations resulted of probable release from aquarium prior to 1981 ( ).

III - Physical-chemistry parameters

Ideal temperature range : 20ºC ( 68.0ºF ) - 29ºC ( 84.2ºF )

Tolerated limits : 10ºC ( 50.0ºF ) and 32ºC ( 89.6ºF )

Survival limits : 7ºC ( 44.6ºF ) and 35ºC ( 95.0ºF )

Ideal pH : 6.7 - 7.8

Ideal dH : 3º - 15º

Maximum salinity : 10004 ( 1,6 ppt )

Temperature annual maintenance for this species in captivity ( suggestion ) :

Thermal regime (1) 

Thermal regime (2)

14ºC ( 57.2ºF )

16ºC ( 60.8ºF )

15ºC ( 59.0ºF )

17ºC ( 62.6ºF )

17ºC ( 62.6ºF )

20ºC ( 68.0ºF )

20ºC ( 68.0ºF )

23ºC ( 73.4º )

22ºC ( 71.6ºF )

24ºC ( 75.2ºF )

24ºC ( 75.2ºF )

25ºC ( 77.0ºF )

25ºC ( 77.0ºF )

26ºC ( 78.8ºF )

26ºC ( 78.8ºF )

28ºC ( 82.4ºF )

25ºC ( 77.0ºF )

26ºC ( 78.8ºF )

23ºC ( 73.4ºF )

25ºC ( 77.0ºF )

19ºC ( 66.2ºF )

22ºC ( 71.6ºF )

17ºC ( 62.6ºF )

19ºC ( 66.2ºF )

Each one of this table lines report a different monthly period.

The temperature values are provided only as a reference for captivity maintenance.

Performing on this way your action can be considered reasonable, according with the species known thermal exigencies.

It is sometimes difficult, if not even impossible, to recreate in aquarium the natural conditions, most favourable for the fish biology. The most ideal situation was, if you could be able to provide your fish a daily as well as a weekly temperature variation, like in the wild.

For better understanding about perfect environment or to simulate water temperature annual evolution according to natural habitat for this species, please be so kind and have a look to Guadalajara graphic at Wild water's temperatures ( all year round ) issue.


IV - Biology and ecology synopsis

This species it’s moderately vegetarian, feeding with frequently of submersed vegetation, besides aquatic invertebrates as well.

Their predisposition for moving waters is demonstrated in captivity. The Ameca behaviour in face of some water agitation it’s of visible happiness, revealing to be a fish anatomically well prepared to swim against currents.

Like the majority of the Goodeids this species benefits with daily thermal amplitudes in the order of around 5ºC ( 41.0ºF ) or 6ºC ( 42.8ºF ) disparity.

A night cooling seems to provide very good results in the health and welfare of the Amecas.

Also a seasonal period of some cold reveals itself vital for their fecundity.

Even so these cooler winters show a considerable slowdown in growth, when compared with those fishes that are kept at slightly warmer temperatures.

If the specie needs are respected and the species maintained in the coolest winter month at least as low as 17ºC ( 62.6ºF ) or 16ºC ( 60.8ºF ), it’s possible to detect an extraordinary behaviour as soon as the temperature reaches as high as around 20ºC ( 68.0ºF ).

The males look after territories and the ones able to impose themselves guard jealously small depressions on the terrain were they flatter the females that pass near by.

The frequent confrontations normally don’t produce visible damage to the belligerents.

After some time it’s even possible to identify the dominant male by it’s coloration and from the power that he behold above all the remaining members of the group.

This is a species that was established in captivity since the beginning of the 1970’s decade, so nowadays they are more tolerant to water conditions slightly different of their origin.

Unfortunately, the domestic exotic forms are becoming more and more frequent, differing from the original wild type, specifically at body colouration.

The older males develop a considerable curve on the back.

It’s interesting to observe that sometimes the females take the initiative of making the flatter They pose themselves in front of their chosen mate and start to tremble. In face of that invitation the respective partner stands by their side and copulate.

Amecas reach the sexual maturity about the 3 or 4 months of age in optimal conditions, although the females just enter in gestation from the 5 months of age on. Unlike Poecilids, the Goodeids don't have the faculty to preserve the sperm. for that reason after each childbirth the females have to be fertilized again.

The medium number of breeds are between 20 and 25, but can be only 2 or 3 in the first gestation and cross by far the 30 in larger females maintained under exceptionally favourable conditions. 

The gestation lasts between 55 and 65 days, depending on the temperature, the quality of the water, the available food and the concentration of specimens. In unfavourable conditions, the pregnancy can be maintained during months. The delivery process can be slow, taking some breeds several hours. In the end of the reproductive season, if temperatures go down below the 18ºC ( 64.4ºF ) some females free their embryos prematurely.

These spontaneous abortions rarely allow the survival of the breeds expelled because they aren’t totally developed.

After the childbirth some recent mothers present their womb so wrinkle that can take us to think they are sick or that they won't survive at all.

Rarely happens but, from time to time, some can even start to suffer from a deformation of the column. With a correct feeding and some rest in a few days begins an amazing recovery on the part of all of the parturient.

Amecas don’t normally pursue their breed. The newly born ones can measure up to 20 mm at birth. Some are pursued until they reach the surface for the first time and fill the respective natatory bladder. After this adults loose the potential cannibalism. If the aquarium is provided with dense vegetation the young don’t get to be upset after that critical phase.

In aquarium, the new born fry feeding can be achievable with success through plankton, but some artificial foods and particles of the food stuff supplied to the adults are also very well accept because at born they are already very developed and large.

The adults in captivity perfectly adapt to the general proposals done in the aquaristics section accepting, for besides a varied menu of vegetable options, brine shrimps and other frozen natural foods, fish or the raw molluscs and milled as well as industrialized foods, ( namely containing a vegetable base spiruline component or other ).

The Ameca splendens was revealed to be a robust and resistant species to most of frequent diseases.

It is also an optimal option on the combat uncontrolled proliferation of noxious algae, at least since the temperature is greater than 22ºC ( 71.6ºF ) as well as when alternatives , like some floating aquatic plants ( Lemna spp ), are scare.

Some submerged unknown plants in original ecosystem, as the Java Moss ( Vesicularia dubyana ), can sudden become an appreciated delicacy as well as target of a obsessive consumption. Seemingly, certain plants are only consumed inside of a certain range of temperatures; while out of that they are left in peace.

V - Complementary notes

Although they are gregarious animals that in nature being found in abundant groups, males as females go into in frequent disputes amongst themselves. This is especially true in the beginning of the reproduction season. Even if not taking in consideration their seasonal territorial habits, because they are excellent swimmers and need some current is inadvisable to maintain the adults in aquariums with less than 160 litres of capacity.

As a rule, Amecas don’t normally attack other species but their vitality contributes to less active species “ stress “.

It is also inadvisable to mix this Goodeid with fishes like Guppy ( Poecilia reticulata ), specially those of varieties obtained by anthropogenic selection with very good-looking colours, because certainly their long fins will be the target of attacks in little no time.

Whenever possible it does better provide some current and make partial water changes every week.

The respective tank should always be covered.

VI - Threats, protection and present status

Some common situations of habitat change contributed to the extermination of the wild populations.

The disforestation, water extraction for human consumption, agricultural activity, rivers contamination with sediments in suspension, domestic sewers discharges, eutrophization and the habitat fragmentation are main causes for extinction.

According to the consulted sources, the disappearance of this and of other endemic Goodeids from the same region it’s above all particularly related with the introduction of exotic species to provide a food source to the local populations.

The most damaging for the local primitive fish fauna in the habitat of Ameca splendens are the American Catfish ( Ameiurus melas ), Tilapia ( Oreochromis spp ) and Black Bass ( Micropterus salmoides ).

For further knowledge or information about this please check Livebearer Cyprinodontiformes in the IUCN Red List of Threatened Species.

Other topics available about this species :

Important notice : This page text was translated from Portuguese to English by Sérgio Calado.

Thank you very much for this work my friend.

We should be extremely gratified and thank you in advance if some one could provide new data about this topic, or even eventually any correction to be made on this document. For this purpose please write us.

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