Zoogoneticus tequila

First Describer: 
Webb & Miller, 1998
Original Description: 

WEBB, S. A. & R. R. MILLER (1998): Zoogoneticus tequila, a new goodeid fish (Cyprinodontiformes) from the Ameca drainage of Mexico, and a rediagnosis of the genus. Occasional Papers of the Museum of Zoology University of Michigan Ann Arbor 725: pp 1 - 23


This species is named for the mexican volcano Tequila, which looms north of the type locality.


Collection-number: UMMZ 233655. The Holotype is a mature male of 26.7mm SL, collected by R. R. Miller and J. T. Greenbank, 25.03.1955.

English Name: 
Tequila Splitfin
Mexican Name: 
Picote tequila

Zoogoneticus sp.    Lambert, 1990


2n = 46    2M/ 2m/ 42stt    (following Webb & Miller, 1998)

The maximum known SL is 48mm (Miller et al, 2005).
Terra typica: 

The Holotype has been collected in the Río Teuchitlán, at the east end of Teuchitlán in Jalisco.

Status after IUCN: 

Critically endangered

Status after J.Lyons (2011): 

Endangered; Comment: One tiny population


This species is (was) restricted to the Río Teuchitlán of the Río Ameca drainage from the Pacific Slope in Jalisco.


The original type - habitat was a shallow and open lake - like expandation of the Río Teuchitlán, 8m in diameter and 1.3m deep. The species prefered depths of less than 1m. The substrates were mainly mud and silt, a few rocks and sand were present. The currents were none to moderate and the water warm (about 26°C in March) and continuously turbid by cattle, pigs and horses. Few plants were living there: Eichhornia, a broad-leaved Potamogeton and hyacinth-like plant. The species disappeared from there at the beginning of the 1990's. Regarding the rediscovery of the species go to "Remarks".


Adult males are dark olivaceous on the sides, back, nape and top of the head. Mottling is present on the side of the body, which often has a greenish hue. Many of the lateral scales are reflective, producing iridescense. The colour fades to pale yellow below the lateral scale series on the belly and below the eye. There is a pair of spots, which usually coalesce, at the base of the caudal fin. The mottling and the basicaudal spots may not be visible during breeding condition, when the body is darkest, nearly black. The unpaired fins are dark, fading towards the margins, with the pigmentation concentrated along the lengths of the rays. The greenish cast of the body can occasionally be seen in the dorsal and anal fins. The borders of the dorsal and anal fins have a thin cream-coloured band. The caudal fin has a broad subterminal red to orange band, and the region proximal to this band is heavily melanized. The pelvic fins occasionally show some terminal cream colouring, but the pectoral fins are unpigmented. Females are olivaceous. The sides, back, nape and top of the head are dark and display mottling, while the belly below the lateral series and the area below the eye are pale yellow. Two to four large spots are found on the ventral half of the caudal peduncle. These spots occasionally fade in older individuals. A pair of basicaudal spots, which typicaly coalesce, are visible in most specimens. The unpaired fins may be dusky, but are not dark, and do not possess the cream-coloured margins that males display. Occasionally large females show a thin subterminal band of red-orange in the caudal fin, but it is less intense than in males. The unpaired fins are clear.


There is not much known about this species in the wild, due to its fast disappearance. Webb and Miller determined, that both sexes become mature within ten weeks when kept by 26-28°C. This could take more time in the wild with lower temperatures. Broods numbered as many as 20 - 29 offspring, fewer than 10 in the first year.


Conical teeth and a rather short gut suggest a carnivorous feeding behavior. Combined with a small mouth, this species is definitely a predator, probably picking small invertebrates like crustaceans and insect larvae in the wild. 


A single male of the Tequila Splitfin was sampled in 1955 by Miller and Greenbank, but identified erroneously as Zoogoneticus quitzeoensis, with which species it was collected and found sympatrically (UMMZ 172224). Many years later, the mistake was detected, the fish identified as a new species and finally, 43 years after the first capture, described by Webb and Miller.

   In 1955, when the fish was taken first, all of the fish at the type locality were abundant, including Skiffia francesae (though the water was turbid by a lot of domestic animals). In 1990, it still was present (also Allotoca maculata) whereas Skiffia francesae had disapperared. Several exotic species had been introduced in the habitat. Since 1992, collections have been unsuccessful. Intensive sampling in 1996 failed to reveal any Goodeid in the type locality. So it took humans not even 40 years to extirpate consequently all species of Goodeids in only one habitat.

   Brian Kabbes detected a young but mature male in the Balneario Teuchitlán in 1999, which gave hope, that the species was still existing there, but no more individuals were seen therafter.

   In 2001, a wild population of this species was rediscovered in a very small spring pool (3 x 4m in diameter). The population there was composed of only a handful of adult fish and a few tens of juveniles (De la Vega-Salazar et al., 2003). In 2007, N. W. Bailey et al showed, that the allelic richness of this population (though it was comparable in size to an aquatic stock) was higher than in any aquatic stock. In 2013 the loss of this population was reported (pers. comm. Domínguez), so there is not much hope that this species is still persisting in the wild.

   This species has been used by A. Arbuatti and P. Lucidi to survey, wether the environmental structure of a tank leads to a change or loss of behavioral richness. Due to the fact, that differences have not been found between enriched tank set ups and natural structures, this study encourages the breeding under captive conditions to conserve this species for a later reintroduction in the natural environment.

   The Goodeid Working Group, Chester Zoo and other organisations will start together with the University of Morelia a reintroduction project for this species (and the critically endangered cyprinid Notropis amecae) in 2015. This project encompasses strategies to get the local residents on board, the building of semicaptive ponds for the acclimatation of captive bred fish, the reintroduction of the fish and a monitoring and scientific guidance over 2 years. The whole project is thought to go over 5 years and would have been the first reintroduction project done with a Goodeid species.


 Images 1 and 2: males

Copyrights by Frank Kroenke

Image 3, 4 and 5: spawning pair

Copyrights by Frank Kroenke

Image 6: face of a male

Copyright by Frank Kroenke

Image 7: competiting males

Copyright by Frank Kroenke

Image 8: pond-raised male

Copyright by Martin Ravn Tversted/ Lars Vig Jensen

Image 9: male

Copyright by Juan Carlos Merino

Image 10: female

Copyright by Juan Carlos Merino

Images 11 and 12: pair

Copyright by Juan Carlos Merino

Image 13: male

Copyright by Leo van der Meer

Image 14: male

Copyright by Roman Slaboch

Image 15: 2 females

Copyright by Roman Slaboch