Chapalichthys encaustus

Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
Chapalichthys encaustus
English Name: 
Barred Splitfin
Mexican Name: 
Pintito de Ocotlán
Original Description: 

  JORDAN, D. S. & J. O. SNYDER (1900): Notes on a collection of fishes from the rivers of Mexico, with description of twenty new species. Bulletin of the United States Fish Commission. 1899: pp 115 - 147

Holotype: 

  Collection-number: L.S.Jr.Univ.Mus. 6163. The Holotype is an adult female, the SL is not documented by the describer. The type has been collected by J. O. Snyder, 26.12.1898.

Terra typica: 

  The Holotype had been caught in the Lago de Chapala, near Ocotlán in Jalisco.

Etymology: 

  The name "encaustus" (lat.) means “burnt in”, probably because of the lateral marks of the adult fish.

Synonyms: 

Characodon encaustus   Jordan & Snyder, 1900

Distribution and ESU's: 

  The Barred Splitfin is endemic to the Mexican federal states of Jalisco and Michoacán. It is historically known from the lower Río Lerma drainage including the Río Lerma itself from about La Piedad and some affluents like the Río Duero and the canales dren Colesio, Zanja Madre and Moreño. It also occured in the Laguna de Chapala and adjacent sections of the Río Grande de Santiago to about the waterfalls at Juanacatlán E of Guadalajara, in the Laguna Cajititlán and a main affluent of the Laguna Chapala in the SW, the Canal Sahuayo including some dams in its headwaters (Presas Jaripo and Nueva). It disappeared from the ríos lerma and Grande de Santiago due to water pollution but still persists at most of the other places though sometimes in reduced numbers (Laguna de Chapala). Strongholds are the Lagos Los Negritos near Sahuayo and the dams around Jacona de Plancarte (Presas Verduzco and Orandino). The species can be found additionally in the Presa La Vega, upper Río Ameca drainage, but this is regarded as an introduced stock. The time and reason for the introduction are not completely solved. Though Chapalichthys were collected together with the types of Ameca splendens by Miller et al., in 1955 (Miller and Fitzsimons, 1971), it stayed almost unnoticed until the early years in this millenium when a single individual has been reported by P. Gesundheit in 2005 (Lyons, 2011). On a survey by Köck et al. in 2016, three adult fish were caught on the N end of the Presa La Vega. According to the affiliation to two river drainages, two subpopulations, the Laguna de Chapala (type subpopulation) and the Lower Río Lerma subpopulation, can be distinguished. The underlined names are the ones officially used by the Instituto Nacional de Estadística y Geografía; nevertheless, other ones might be more often in use or better known and therefore prefered.

 

    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 the first 3 letters of the genus, followed by the first 2 letters of the species name and an ongoing number in each species.

 

  In Chapalichthys encaustus, no different ESU's are distinguished, so all fish belong to Chaen1.

 

  Maximum Extent of Occurence of Chapalichthys encaustus:

Maximum EOO of Chapalichthys encaustus

Status : 

  International Union for Conservation of Nature (IUCN): not assessed

 

  Conservation status and population trends of Mexican Goodeids (Lyons, 2011): vulnerable/declining – This species was formerly abundant throughout nearshore areas of Lake Chapala and was also encountered in adjacent areas of the Lerma and Santiago rivers and their tributaries (Lyons et al. 1998). Since the late 1990s, C. encaustus has disappeared from the mainstem Santiago and Lerma rivers due to pollution and has become much less common in Lake Chapala owing to the invasions of the non-native livebearers Poecilia sphenops and Gambusia yucatana (Poeciliidae) (Becerra-Muñoz et al. 2003). Chapalichthys encaustus still persists in the lower portion of the Duero River drainage, a Lerma River tributary, including the La Luz and Orandino lakes, and also in Cajititlán and Los Negritos lakes, both near Lake Chapala. In 2005, a single individual was collected from La Vega Reservoir in the upper Ameca River basin, probably introduced during a stocking of blue tilapia, but there is no indication that C. encaustus has become established there (Pablo Gesundheit-Montero, Universidad Nacional Autónoma de Mexico, Mexico City, personal communication).

 

  NOM-059-SEMARNAT-2010: no categoría de riesgo (no category of risk)

Habitat: 

  This fish lives in quiet waters of lakes, ponds and river channels, where currents are usually slow to none, but may be moderate. Vegetation there is usually sparse to none. When there is vegetation, it is composed of green algae, water hyacinths and Scirpus. The substrates are made of silt, mud, clay, sand and rocks. The waterbodies are rarely deeper than 1.3m, commonly the depth is less than 1m. The water can be from turbid to muddy (after Miller).

  Brian Kabbes caught this species in a channel in Michoacán in December 1998. The water had been muddy with the sight below 10cm. The water temperature had been around 16°C in the morning. In the Lago de Chapala, near the village Chapala, he documented young fish, but few adults, probably because of th polluted waters near the village. Anyway, the Lago de Chapala belongs to the most endangered lakes in the world with a heavily decreasing watersurface and massive polluted water.

 

Estancia de Igartua IEstancia de Igartua II

 

Manantial La Luz IManantial La Luz II

 

Manantial La Luz IIIManantial La Luz IV

 

Lago de Chapala ILago de Chapala II

 

Los Negritos ILos Negritos II

Biology: 

  Young fish with 9.0mm SL taken from Lago de Chapala on 26 March and a 16mm fish taken on 23 May suggest that the reproduction occurs during spring. Meek (1904) stated that young were born in the latter part of May. He found 21 near-term embryos each 10mm long in a female 68mm long.

Diet: 

  The bifid teeth, the long convoluted gut and 20-28 slender gill rakers suggest it is herbivorous. Nevertheless, some observers documented this species jumping out of the water and catching flying insects in the Lago de Chapala.

Size: 
The maximum known SL is 93mm (Miller et al, 2005).
Colouration: 

  Jordan & Snyder wrote about the colouration in their description: "Color in alcohol light yellowish-olive; 9 short and narrow dark vertical bands on median part of body; the first above base of pectoral; the ninth at base of caudal; scales on dorsal region of body edged with black dots; upper part of head dark; upper half of orbit black; opercles silvery; dorsal fin with a little dusky; other fins without dark color.”

 

  In life, the ground colour is somehow silvery shining. Adults get yellow fin margins, sometimes totally yellowish. Especially the pectoral fins appear often yellow to orange. Adult fish (females?) present a yellow to orange coloured venter.

Remarks: 

  The whole fish are dried in the sun for food around Lago de Chapala, where this abundant species is taken by commercial fishermen. Hieronimus (1995: pl.4, opposite p.90) recorded the species from the Atlantic Slope in the Río San Juan del Río in Queretaro. I judge this to be another interbasin transfer by human action. Earlier collections at this locality revealed two cyprinids and Goodea atripinnis (as Goodea gracilis Hubbs and Turner).

 

  In France have been selected some albinotic specimens and distributed in the Hobby. As far as we know, these are the only documented albinotic Goodeids.

Locations