Ataeniobius toweri

Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Goodeid
Original Description: 

  MEEK, S. E. (1904): The fresh-water fishes of Mexico north of the Isthmus of Tehuantepec. Publication. Field Columbian Museum 93, Zoological Series 5: pp 138 - 139

Etymology: 

  The species is named for its discoverer, Dr. W. L. Tower of the University of Chicago.

Holotype: 

  Collection-number: Field Columbian Museum, Cat. No. FCM-4519.

  The Holotype is an adult female of 60.4mm standard length (2.38 inches), collected probably by its discoverer, W. L. Tower.

English Name: 
Bluetail Splitfin
Mexican Name: 
Mexclapique cola azul
Synonyms: 

Goodea toweri   Meek, 1904

Karyotype: 

  The Karyotype describes the number and appearance of chromosomes during the phase of condensation, classified by the position of the centromere (Levan et al., 1964).

The following abbreviations are employed:

 

M = large metacentric chromsome (a result of Robertsonian fusion)

m = small metacentric chromsome (centromere at medium position)

sm = submetacentric chromsome (centromere at submedian position)

smst = submetacentric-subtelocentric chromosome (continous series)

st = subtelocentric chromosome (centromere at subterminal region)

stt = subtelocentric-acrocentric chromosome (continous series)

t = acrocentric chromosome (centromere at terminal region)

 

The Karyotype of Ataeniobius toweri, following Uyeno, Miller & Fitzsimons, 1983:

2n = 48    2sm/ 46stt  

Size: 
The maximum known SL is 76 mm (Miller et al, 2005).
Terra typica: 

  Meek wrote in his description simply: Río Verde, San Luis Potosí.

Status after IUCN: 

not mentioned

Status following other sources: 

Endangered; Comment: Stable since 2000

Distribution and ESU's: 

This species comes from the Atlantic Slope and is restricted to the upper Río Verde drainage (elevation 1000-1100m) around La Media Luna and its vicinity near Río Verde and in Puerta del Río (source of Río Verde), south of Villa Juárez (Río Panuco basin) in the state of San Luis Potosí.

Habitat: 

Ataeniobius toweri lives typically in quiet water with little or no current. It can be found along shallow margins of lagoons, marshes and ditches, but also in creeks where currents may be moderately strong. It prefers depths to 1m with the water very clear, but it may also be a bit murky. Typical vegetation associated with the Bluetail Splitfin are species of Nymphaea, Scirpus, Juncus and Eichhornia and green algae. The substrate is made of flocculent silt, mud, sand, gravel and rocks.

 

Dominic Isla documented big schools of this fish in La Media Luna, prefering strong currents.

 

After L. Wischnath, La Media Luna includes an area with several warm springs and is located about 10km southwest of the city of Río Verde. Water from two caves forms a catchment area or reservoir that the natives call a lagoon. The clear water smells strongly sulfurous and the temperature ranges between 26° and 30°C.

 

El Aguaje IEl Aguaje II

 

El Aguaje IIIEl Aguaje IV

Colouration: 

Meek denoted the colour in his orginal description as "dark brownish above, lighter below. Where the light and the dark colors meet the side more or less speckled; a narrow dark shade on middle of caudal peduncle."

This is the colouration of preserved specimens. In life, the colour appears light grey (somewhat silver-grey) with two dark lines, one of them extends from the middle of the eye backwards to the caudal fin, the second one somewhat from the pectoral fin to the lower edge of the caudal fin. Some specimens show a varying number of vertical bars on the posterior half of the body, mainly on the caudal peduncle, extending from the end of the belly to the caudal fin. The number varies from 4 to 11. Breeding males show an azure caudal fin and whitish anal fin, some males become totally light bluish.

Biology: 

This species may be reproducing over a long period as individuals 11 and 14mm long were collected between 25 November and 19 March, and pregnant females were taken on 18 May in a ciénega 10km south of Río Verde. Young fish occur in very shallow water (about 5cm) where sedges and grass are abundant. Growth and development progress slowly with sexual maturity occuring in six to seven months.

Diet: 

This species appears to be an ambush predator, waiting for small crustaceens to come close, but on the other hand, a long gut and a lot of filamentous green algae in the habitat suggest omnivorous to herbivorous feeding habits. The related Goodea species are herbivorous.

Remarks: 

This is the only species of livebearing Goodeids without showing trophotaenia in young born fry. In 1939, Hubbs & Turner created the genus Ataeniobius for this species. Owing to the apparent lack of trophotaenia, this species was thought by them to be the most primitive Goodeid. Turner stated in 1940, that embryos clearly must absorb nutritents by other means. In 1983, Uyeno et al. suggested that the trophotaenia may have been lost secondarily, but finally in 1989, Lombardi et al. showed that anal processes of near-term embryos, examined by light and electron microscopy, have prototypic trophotaenia. Large embryos and a large finfold, combined with a lack of competition with any other Goodeid, may explain the loss of functional trophotaenia in newborn fish (saving costs of having them?).

 

Together with its relatives from the genus Goodea, Ataeniobius toweri is the most easterly member of the family Goodeidae.

 

L.Wischnath predicated this species as difficult in tank keeping due to its sulfurous-water origin. He refers to especially fungal infection.

 

Brian Kabbes visited La Media Luna in 1999 and pointed to the intensive application of the lagoon as resort and the usage of the outflow to water the surrounding fields. He also documented a partially destruction of the habitat according to that. Recently, the species disappeared from 3 out of 7 historically known sites, and the populations in the remaining 4 are small.

 

An interesting cohabitant of this Goodeid fish is the Checkered Pupfish, Cualac tesselatus, who has a similar blue-tailed colour pattern.

 

Last phylogenetically studies on Goodeids revealed Ataeniobius toweri being related with the genus Skiffia and should belong to the Girardinichthyini tribe according with Domínguez, whereas Goodea should belong to the Chapalichthyini tribe (Domínguez, pers. comm. 2012). However, the position of both genera within the Goodeids is still not solved satisfiable, seeing them somewhere located between both tribes.

Husbandry: 

 

Attention: This are not the correct husbandry guidelines for this species, it is just a working template that needs to be adapted!!!

  

  Looking on the biotopes of Allodontichthys hubbsi, they suggest the species may prefer a habitat with moderate to swift current, structured with gravel, rocks and boulders. Most breeders observed a high level of aggression between the adult fish, so the tank set up should prevent the fish from seeing each other most of the time. Fry is eaten in most of the cases, but it may depend on the quantity and quality of food and on the number of space to hide. When several different stages of juveniles occur, fry may be neglected, so it makes sense to add separate brought up fry to the group with a size of 1.5 or 2cm to provide these stages and get a flock breeding colony. Unfortunately, it was not able until now to breed bigger colonies so this statement is made from the comparison with related species and the personal comments of successful breeders.

 

 The recommended tank size is at least 150 liters, bigger ones with a generous base and little height (25cm are enough) are better for sure. With rocks well structured tanks combined with some roots and/ or wood seem to do best with this species. The current should be moderate or swift. 

 

 In the wild, the species seem to feed from small or middle - sized invertebrates like bloodworms or insect larvae, so feeding with similar food, Daphnia, Mysis and other food from animalistic sources will be best for this predatory fish.   

 

 Concerning water quality, this species is in need of greater water changes (60 - 80% every week) like most of the Goodeids, especially river inhabiting species, so an automatic water changing system can be helpful. Otherwise, in combination with constant temperatures higher than 24°C, fish may get sick, lose resistance against diseases and age too fast. So for keeping the strain healthy and strong, give the fish a rest during winter time with temperatures lower than 20°C for 2 or 3 months so they stop producing fry. In spring, when the temperature slowly increases, they will start spawning at 20 or 21°C and won't stop until it gets colder again or when it gets too warm (25°C?).

 

 This species may do very well when is kept in the open from spring to fall, starting when the temperature exceeds 15°C water temperature and cold periods are no longer expected. During the warm summer, reproduction will stop and may occur again in fall. Bring the fish in before the temperature goes below 10°C water temperature and keep them cool for the first days, then slowly raise the temperature but try to stay below 20°C over the winter time.

Photos: 

Images 1 to 3: male from the Laguna Media Luna

Copyrights by Omar Domínguez Domínguez

Image 4: female from the Laguna Media Luna

Copyright by Omar Domínguez Domínguez

Image 5 and 6: male from El Cedral

Copyright by Omar Domínguez Domínguez

Image 7: female

Image 8: male

Image 9: pair

Image 10 and 11: male (Lago de Creda?)

Image 12: female (Lago de Creda?)

Images 13, 14, 15, 16 and 17: male

Images 18 and 19: male from the Lago de Creda near Media Luna

Copyright: Anton Lamboj

Images 20 - 22: female from the Lago de Creda

Copyright: Anton Lamboj

Image 23: young male from Villa Juarez

Copyright by Guenther Schleussner

 

 

Locations