Hubbsina turneri (including G. ireneae)

Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Hubbsina turneri
Original Description: 

  DE BUEN, F. (1941): Un nuevo Género de la Familia Goodeidae Perteneciente a la Fauna Ictiológica Mexicana. Anales de la Escuela Nacional de Ciencias Biológicas 2 (2-3): pp 133 - 141

Etymology: 

  This species is dedicated to C.L. Turner, probably for his important part in studying Goodeids.

Holotype: 

  Collection-number: The Holotype is deposited without Catalogue number in "La Estación Limnológica de Pátzcuaro".

English Name: 
Highland Splitfin
Mexican Name: 
Mexclapique Michoacano
Synonyms: 

Girardinichthys turneri   Radda, 1984 (partially)

Girardinichthys ireneae   Radda, 2003 (partially)

 

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 Hubbsina turneri, following Uyeno, Miller & Fitzsimons, 1983:

2n = 48    48 stt  

Size: 
The maximum known SL is 58mm.
Terra typica: 

  The Holotype comes from "the waters of the Presa de Cointzio" in Michoacán.

Status : 

  International Union for Conservation of Nature (IUCN): critically endangered

 

  Conservation status and population trends of Mexican Goodeids (Lyons, 2011): Girardinichthys ireneae: critically endangered/declining – Until recently, this species was considered to be part of Hubbsina turneri (Domínguez-Domínguez et al. 2005; Miller et al. 2005). When Radda and Meyer (2003) subsumed Hubbsina within Girardinichthys, they split the former H. turneri into two species, G. ireneae and G. turneri. Girardinichthys ireneae, as currently defined, is known only from the upper portion of the Angulo River drainage of the Lerma River basin, primarily in Lake Zacapu and a few smaller spring-fed lakes nearby. It appears to have disappeared from the smaller lakes since the 1990’s and persists only in Lake Zacapu. Girardinichthys (Hubbsina) turneri: Extinct/No records since 1980s – As defined by Radda and Meyer (2003), this species was limited to Yuriria Lake in the Lerma River basin and the nearby endorheic Lake Cuitzeo/Grande de Morelia River basin. These two areas have been heavily polluted and modified, and no G. turneri have been observed in either area since the late 1980s despite repeated and intensive targeted sampling, strongly suggesting that the species is extinct in the wild (Soto-Galera et al. 1999; Domínguez-Domínguez et al. 2005b). Unfortunately, it appears that no captive populations exist, so the species may be completely extinct.

 

  NOM-059-SEMARNAT-2010: Categoría de riesgo (Category of risk): P - En Peligro de Extinción (in danger of extinction)

Distribution and ESU's: 

  This species comes from the endorheic basin of the Río Grande de Morelia (including the Lago de Cuitzeo), the Lago de Yuriria and from the exorheic Laguna de Zacapu and its outlet in the northeast, the Río Angulo, about 30 - 35km NE of the town of Zacapu, federal states of Michoacán and Guanajuato.   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.   Concerning Hubbsina turneri, we are able to distinguish two ESU's, corresponding with the separation into two species after Radda & Meyer in 2003. Though Lyons follows the Radda taxonomy including ireneae and turneri in the genus Girardinichthys, after clear phyloegentic results, the genus Hubbsina has to be treated as valid. So finally we have two different ESU - systems in Hubbsina turneri: Hubtu1 (resp. Girtu1) is in use for fish from the Lago de Cuitzeo/ Río Grande de Morelia basin, whereas Hubtu2 (resp. Girir1) for the fish from the Laguna Zacapu/ Río Angulo system. 

Habitat: 

  This species lives in quiet waters with currents none to slight of lakes, ponds, canals and ditches. The substrates in the habitats are mainly mud, silt, clay, sand, rocks and decaying organic matter. It prefers depths less than 1.3m. The water is clear to usually turbid or muddy, vegetation is present and dense, mainly green algae, Potamogeton, Eichhornia, Typha and Scirpus. The Laguna de Zacapu is a spring-fed lake, drained by the Río Angulo, which divides in two streams after 20km. The habitat is 0.5 to 1m deep and the ground is predominantly of mud which leads to a translucent (greenish) to turbid water. The Highland Splitfin prefers well planted areas, where it is hiding under the aquatic vegetation, including Chara, Potamogeton, Ceratophyllum and green algae.

Colouration: 

  De Buen described the colour of the preserved Holotype, a female, as "dark on the back and yellowish-white on the venter. On the sides it has got several dark blotches, mainly extending vertically. They appear on the venter and the lower part of the caudal peduncle. Unpaired fins are spotted, mainly the dorsal fin, the other fins are clear." The Alotpye, a male, he described as gray on the back and the sides, yellowish on the venter. No blotches visible; only between the rays of the caudal fin there are some dark chromatophores. On the upper part of the back are some narrow longitudinal- spaces without colouration. The dorsal fin shows some dark-coloured areas between the rays, the caudal base has got some coloured blotches. The pelvic and pectoral fins are clear. The anal fin has got some blotches". Radda and Meyer wrote in their description of Girardinichthys ireneae about the colouration simply: "Males of G. ireneae sp.n. (as well as females) have numerous dark spots on body and dorsal fin."

 

  In life, this species appears golden-brown to yellowish-brown with several irregular and different-sized blotches in both sexes. The caudal peduncle, the posterior part of the venter and the base of the dorsal fin are more prominent spotted. Some individuals show a line of blotches on the base of the dorsal fin. The lower side of the head and the anterior part of the venter are coloured golden, yellow or creme without blotches. The dorsal part appears brighter than the ventral part with smaller blotches and spots, more dusky than dark. The fins are clear with some dark speckles.

Biology: 

  G. Mendoza took newborn fish on 26 May 1956, so this indicates that young are born at least from May through August. The broods are large, big females have 20 - 40 each. Brian Kabbes documented a territorial behaviour of this species (1999). He caught a conspicuous male and released it again at an other place. After some time, it was back again. He tried this several times with the same fish, and it came back again each time. J.K. Langhammer (1991) anticipates a nocturnal or crepuscular behaviour, derived from personal observations in captivity and from observations of collectors in the wild.

Diet: 

  The teeth have not been examined in the original description, but this species feeds in captivity nearly exclusively from small micro-crustaceans, like Cyclops and Daphnia. Together with its hiding mode of life and a diurnal migration of planctonic invertebrates in lakes ans ponds, it seems that Hubbsina turneri is a  food specialists, picking up small plantonic organisms over the ground.

Remarks: 

   J. K. Langhammer (1999) indicated that Hubbsina turneri differs from other Goodeids in its nocturnal behaviour: "By day it disappears into 'caves' of coconut shells and flower pots of the type used by dwarf cichlids". Possibly correlated with this behaviour is the pale back and dark venter, the reverse of colouration in other, usually diurnal, Goodeids, he stated. Langhammer also posted that "Miller collected significant numbers in deep and very turbid water, similar to Derek and Pat Lambert, who found their best collections occured after heavy rains and on overcast days." Derek Lambert said, following Langhammer again, "that the only time, he has had luck on bright days was by collecting in well-shaded areas away from open water." All of these successful collections happened under conditions simulating dusk or darkness. On several trips to the Laguna de Zacapu, members of the Goodeid Working Group were looking for Hubbsina. By day it was hard to find them, but at dusk the appeared out of the dense roots from surrounding trees that reached into the water.

 

  Most scientists don't treat Girardinichtys ireneae as valid (Doadrio, Dominguez), though there are some (but few and weak) differences in the number of fin rays and scales. However, according to molecular and taxonomic studies (Moncayo-Estrada 1993, Doadrio & Dominguez 2004), the species turneri and ireneae are not distinguishable (after Herrejón et al). Domínguez (pers. comitt. 2011) pointed at the fact, that the description of both species had been done with only very few specimens and that the differences might not be big enough to separate them from each other. However, Girardinichthys ireneae is definitely a member of the genus Hubbsina and does highest probably belong to the same species, so we treat them as one species on this page here. Hubbsina turneri is unique having the highest number of dorsal rays among known Goodeids.

 

  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), the distribution pattern of these plants has importance for the Zacapu fish fauna, which includes besides Hubbsina six more Goodeid species and a few from other families including some exotics like the common carp. There is no report about Hubbsina turneri from the Lago de Cuitzeo/ Río Grande de Morelia basin since 1980, so this populations seem to be extinct.

 

Location