Allotoca maculata

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Original Description: 

  SMITH, M. L. & R. R. MILLER (1980): Allotoca maculata, a new Species of Goodeid Fish from Western México, with comments on Allotoca dugesi. Copeia 3: pp 408 - 417

Etymology: 

  The name is derived from the Latin and means "with a spot", in reference to the black basicaudal spot.

Holotype: 

  Collection-number: University of Michigan Museum and Zoology, Cat. No. UMMZ-200250.

  The Holotype is a mature male of 27.2mm standard length, collected by R. R. Miller & J. M. Fitzsimons, 22.02.1970.

English Name: 
Blackspot Allotoca
Mexican Name: 
Tiro manchado
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 maculata, following Uyeno, Miller & Fitzsimons, 1983:

2n = 48    4st/ 44t  

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

  The Holotype comes from the Laguna de Santa Magdalena, JAL, about 82km W of Guadalajara at HW 15. 103°57'W long and 20°54' N lat., about 1210m elevation.

Status after IUCN: 

  Critically endangered

Status following other sources: 

  Endangered; Comment: Only remnant populations

Distribution and ESU's: 

  This species is confined to the endorheic Lago de Magdalena basin, about 80km west of Guadalajara in Jalisco.

Habitat: 

  It inhabits shallow lake margins and ciénegas in clear to muddy water over easily roiled, soft-mud substrates. It prefers depths of less than 0.5m. In the dry season it survives well in the very shallow, well-vegetated water of shrinking lentic habitats. The vegetation may be sparse to absent, but water hyacinths have been dense at the type locality when collections were made in 1957 and 1970. Some Hydrocotyle were also present. The late afternoon water temperature on 27 February 1957 and 22 February 1970 were 15.5 and 16.2°C, respectively.

 

  In the late 1990, some new habitats of this species have been detected, for example El Palo Verde and ditches and pools around San Marcos. All of these habitats are part of the endorheic Magdalena-basin.

 

Pool at Palo Verde IPool at Palo Verde II

 

Palo Verde IPalo Verde II

Colouration: 

  Adults are light grey-green dorsally and silvery below. The colour of the backs of females extends onto the sides in three to six vertical bars separated by four to seven prominent blotches of light iridescent blue. These dark vertical or obliquely directed bars are weak and diffuse anteriorly, most prominent above vent and anal fin and typically number only one posterior to the base of the anal fin. Females have one or more irregular dark spots situated on the caudal peduncle. Males have a lateral series of fine dark spots beginning behind the opercle and becoming denser posteriorly with the spots usually coalescing to form a diffuse lateral stripe on the caudal peduncle that ends in a dense spot the size of the pupil at the caudal base. Many males bear a dark lateral spot below or slightly in advance of the dorsal fin origin. Backs and sides of males are generally grey-green with flecks of iridescent blue showing through on lower sides, especially during the courtship. The preopercle and opercle in both sexes are metallic blue and the cornea is golden. The perianal region is often dusky, sometimes heavily so in females. The fins are mostly clear but with a dusky colour on the interradial membranes. The caudal fin may take on a light yellow colour in courting males.

Biology: 

  R.R. Miller collected females in late February 1970 being pregnant and individuals 10mm long were captured between 22 and 27 February. 

 

  Allotoca maculata generally prefers to hide in dense plant stands; if there is no vegetation, it hides near the shore.

Diet: 

  The conical teeth with those in the outer row enlarged (like in all Allotoca) indicate carnivorous feeding habits. Because of its posteriorly set unpaired fins, it might be that Allotoca-species hunt like small pikes.

Remarks: 

  In the years 1980 and 1982, during a long dry period, the Lago de Magdalena dried totally out and this species has not been captured for many years (between 1971 and 1990). Therefore it was reported extinct by Miller in 1990. M. L. Smith rediscovered it in an artificial pond near the dry bed of Lago de Magdalena.  

 

  In 1999 and 2000, Brian Kabbes examined several habitats in the endorheic Magdalena-basin and found Allotoca maculata widly distributed and sometimes in masses (pers. comm. to G. Ellenberg in 2001). Most of these habitats are small ditches, pools or small muddy lakes (for examples channels and ditches around San Marcos and Granja Sahuaripa), some of them well planted, others with open water-surface. Last results and phylogenetically examinations revealed these populations as belonging to an undescribed species, being in description already (Domínguez, pers. comm.2011) and close to maculata (Allotoca sp. "Etzatlán").

 

  S. Webb labels this species as the most basal among Allotoca due to some phylogenetical characters.

Husbandry: 
  Looking on the biotopes of Allotoca maculata, 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: 
Smith & Miller, 1980
Photos: 

Image 1: male

Image 2: male of Allotoca sp. "Etzatlán" from Palo Verde

Copyright by Omar Domínguez Domínguez

Image 3: female of Allotoca sp. "Etzatlán" from Palo Verde

Copyright by Omar Domínguez Domínguez

Image 4: male

Images 5, 6, 7 and 8: female