Allotoca zacapuensis

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Original Description: 

  MEYER, M. K., RADDA, A. C. & O. DOMINGUEZ-DOMINGUEZ (2001): Notes on the genera Neoophorus HUBBS & TURNER, 1937 and Allotoca HUBBS & TURNER, 1937, with a description of a new species of Allotoca from Laguna de Zacapu, Michoacán, Mexico (Teleostei, Cyprinodontiformes: Goodeidae). Annalen des Naturhistorischen Museums in Wien (103B): pp 453 - 460

Etymology: 

  The name of this species is derived from the Laguna de Zacapu, which is the only known habitat.

Holotype: 

  Collection-number: Naturhistorisches Museum Wien, Cat. No. NMW-94584.

  The Holotype is a young male of 22.1mm SL, collected by M.K. Meyer, A. C. Radda and C. E. Rivas Benitez, 14.02.2001.

English Name: 
Zacapu Allotoca
Mexican Name: 
Tiro de Lago de Zacapu
Synonyms: 

  none

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 Allotoca zacapuensis has not been ascertained.

Size: 
The maximum known SL is 50mm (Miller et al, 2005).
Terra typica: 

  The Holotype comes from the Lago (also named Laguna) de Zacapu in Michoacán.

Status after IUCN: 

  not assessed

Status following other sources: 

  Endangered; Comment: Stable but very rare

Distribution and ESU's: 

  This species is restricted to the Laguna (or Lago) de Zacapu and its outlet in the northeast, the Río Angulo, in the state of Michoacán.

 

  ESU ist short for Evolutionarily Significant Unit.  Each unit expresses an isolated population with different genetic characteristics within one species.  ESU's can be defined by Molecular genetics, Morphology and/or Zoogeography and help in indicating different phylogenetic lineages within a species. The abbreviation for an ESU is composed of three letters of the genus, followed by the first two letters of the species name and an ongoing number in each species.

 

  All fish from this species belong to one ESU, so in Allotoca zacapuensis there is only Altza1.

Habitat: 

  The Laguna de Zacapu is a spring-fed lake. The habitat at the collection point is 0.5 to 1m deep and the ground is predominantly of mud which leads to a translucent (greenish) to turbid water. The Zacapu Allotoca prefers well planted areas, where it is hiding under the aquatic vegetation, including Chara, Potamogeton, Ceratophyllum and green algae.

Colouration: 

  The ground colour of the body is greyish brown in both sexes. Blue, pink and green colour reflections appear along the midline and venter. The body side shows one series of 10 to 14 vertical bars, which are broad and most prominent on the rear body half. The longitudinal region has got sometimes dark blotches, most abundant in the middle. The scales of the upper body sides present a dark coloured reticulum. The abdominal region posseses a dark brown coloured area. The dorsal fin is light orange, anal fin and caudal fin are light yellow or orange, the paired fins are hyaline.

Biology: 

  Relatively poor things are known about this species. Observations in captivity suggest, that this species is difficult to keep by temperatures higher than 22°C. In the Laguna, the Zacapu Allotoca can be found along the shore, generally hiding under aquatic vegetation.

Diet: 

  The teeth are typical for Allotoca and suggest a carnivorous feeding habit.

Remarks: 

  The Zacapu-lagoon had been once a large cienega (33 500ha), but has been drained to provide land for cultivation. It is now a small waterbody with only 33.5ha in size. It posseses a rich aquatic vegetation (more than a dozen abundant plants and some more species) and the distribution pattern of these plants has importance for the Zacapu fish fauna, which includes besides this Allotoca six more Goodeid species and a few from other families including some exotics like the common carp.

 

  Allotoca zacapuensis has been the last described Allotoca species until now. A distinct Allotoca-form from San Isidro is in description (pers. comm. Dominguez 2011). Miller reported some forms "probably referable to Allotoca" from Lago de Chapala, the Rió Balsas basin and Río Armería basin in 1987, when he described Allotoca goslinei. He labeled these forms as problematic to describe or identify because of poor material.

 

  Recently, this species has been collected in only 2 sites and was absent from about 95% (!) of the total Lake Zacapu area.

Husbandry: 

  Looking on the biotopes of Allotoca zacapuensis, they suggest the species may prefer a habitat with moderate to swift current, structured with gravel, rocks, roots, branches, fallen leaves and river bank vegetation. 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.

 

 The recommended tank size is at least 100 liters, bigger ones with a generous base and little height (25cm are enough) are better for sure. With rocks and vegetation in the corners and backsinde of the tank 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 and spring 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. Allotoca species can be kept down to temperatures of 15 or 16°C without problems for months, some species even lower. 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 is doing 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.

First Describer: 
Meyer, Radda & Domínguez, 2001
Photos: 

Images 1, 2 and 3: male

Images 4, 5 and 6: male

Images 7 and 8: male

Copyright:Anton Lamboj

Images 9 and 10: females

Copyright: Anton Lamboj

Images 11 - 13: male

Copyright: Anton Lamboj

Images 14 and 15: female

Copyright: Anton Lamboj

Image 16: pair

Copyright: Anton Lamboj

Image 17: male

Copyright by Wolfgang Gessl (www.pisces.at)

Image 18: female

Copyright by Wolfgang Gessl (www.pisces.at)