|Scientific Name:||Astroblepus ubidiai (Pellegrin, 1931)|
|Red List Category & Criteria:||Critically Endangered B2ab(iii,iv,v) ver 3.1|
|Assessor(s):||Arguello, P. & Jimenez-Prado, P.|
|Reviewer(s):||Cox, N.A. & Harrison, I.J.|
Astroblepus ubidiai is known from six subpopulations, distributed in four different drainage basins, and their probabilities of escape to other refugia when the environment deteriorates are very limited due to natural and anthropogenic barriers between drainages. Total area of occupancy is estimated at less than 10 km². The species' habitat is being affected by water extraction for pasture, periodic vegetation clearing from creeks by communities in order to improve the water supply, and pollution from urban areas (traditional practice of cloth washing in the water in springs, creeks and streams, traditional practice of using aquatic bodies as corridors to move the cattle within the watershed, use of the local agave called "cabuya" for washing clothes in the creeks and streams is known to have active chemical substances that kill aquatic fauna, including fish). The use of preñadilla as bait for largemouth bass fishing and for food consumption is likely causing a decline in the number of mature individuals. The species is therefore listed as Critically Endangered.
|Previously published Red List assessments:|
|Range Description:||Astroblepus ubidiai is the only historically documented native fish of the Imbakucha basin, Imbabura Province, Ecuador (Vélez-Espino 2006). Recently, it was found in the Azuay province above 2,500 m asl, in the Llaviuco river (Nugra 2014) but this data needs confirmation. Preñadilla is the local name for all Astroblepus species of the Ecuadorian Andes regardless of taxonomic differences. In other areas of the Ecuadorian Andes "preñadilla" has been declared as extinct (Ministerio de Relaciones Exteriores 1992). The species was more widely distributed in the Imbakucha basin in the past, but it is now restricted to a few isolated refuges (Vélez-Espino 2005, 2006). This assessment is based on the original distribution until the new record in the Azuay province is confirmed. The species occurs between 2,000 to 2,800 m asl. The area of occupancy is estimated at 9 km².|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Six A. ubidiai subpopulations were located in the region from information provided by indigenous residents, followed by extensive field surveys (Vélez-Espino 2006). These subpopulations are distributed in four different drainage basins and their probabilities of escape to other refugia when the environment deteriorates are very limited due to natural and anthropogenic barriers between drainages (Vélez-Espino 2006). Pasture grounds, fields, human settlements, and the presence of the piscivorous largemouth bass (Micropterus salmoides) in Imbakucha Lake appear to have resulted in the segregation of those populations within this watershed (Vélez-Espino 2005). |
Each sub-population appears demographically independent (Vélez-Espino 2006), thus the population is considered as severely fragmented as most of its individuals are in isolated sub-populations (Velez-Espino and Fox 2005). During a field study carried out between 2000-2001 in the area where the species occurs, the disappearance of one sub-population in the Imbakucha basin was witnessed (Vélez-Espino 2005).
Fishing pressure, either for food or bait, may be affecting the adult portion of the population (Vélez-Espino 2005), probably causing a decline in the number of mature individuals.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Extensive sampling showed that this species is not presently found in Imbakucha Lake and that individuals are concentrated in small lotic-habitat fragments characterized by the presence of springs (Vélez-Espino and Fox 2005). Individuals of Astroblepus ubidiai are concentrated in small areas (range 40–650 m²) and restricted to island-like habitats, which can be properly defined as refuges (Vélez-Espino 2005). The fact that the habitats of all subpopulations are either springs or headwaters is probably not because those are the keystone habitats, but because those are the habitats least favourable to the causes of decline (Vélez-Espino 2006). |
Preñadilla’s use of underground refugia was first mentioned by Humboldt and Bonpland (1805). Vélez-Espino (2005) observed preñadilla to enter interstitial spaces and penetrate into the outlet of springs. The importance of underground water in the life cycle of the species is not known but the genus Astroblepus is known to have troglobitic (exclusively subterranean) and troglophilic (facultative subterranean) species.
A continuing decline in the in the extent and quality of the habitat has been observed due mainly to pollution from urban areas.
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||This species is used as bait for largemouth bass and for local consumption.|
Standard anthropogenic perturbations to this species' habitat are the deviation of water currents towards pasture grounds, the periodic vegetation clearing from creeks by communities in order to improve the water supply, the use of preñadilla as bait for largemouth bass fishing, the traditional custom of cloth washing in the water in springs, creeks and streams, and the traditional custom also of using aquatic bodies as corridors to move the cattle within the watershed (Vélez-Espino 2005). The use of the local agave called "cabuya" (Cactaceae) for the washing of clothes in the creeks and streams is known to have active chemical substances that kill aquatic fauna, including fish (Vélez-Espino 2006).
Overfishing may not have been a problem before the population was fragmented by habitat loss (Vélez-Espino 2006). The current fragmentation between subpopulations within the Imbakucha basin has been enhanced by the introduction of exotics (Vélez-Espino 2003). The concentration of A. ubidiai in a few small localities increases its vulnerability and jeopardizes its persistence, as there is lower probability that dispersers successfully reach other refuges, thus hindering a positive effect of migration on the regional population size (Vélez-Espino 2003). During the recovery of the traditional ecological knowledge it was evident that five of former preñadilla habitats were converted into reservoirs for human supply and floriculture, four were transformed into community-washing places, two were dried as a consequence of inappropriate agricultural activities, and one was converted into a religious sanctuary (the cave called "El Socavón" which traditional knowledge recognized as a former source of preñadilla) (Vélez-Espino 2006). Another former refuge, the Araque spring, was observed in February 2000 to contain the species, but by July of the same year it no longer contained preñadilla (Vélez-Espino 2003).
In the Imbakucha basin (Proaño, Gallopogyo and Quinde), all six anthropogenic perturbations occur in all of the sites (Vélez-Espino 2006). Approximately 30,000 inhabitants distributed in 38 communities within an area of 150 km² have impacted on preñadilla habitat and could be a cause of the poor habitat quality (Vélez-Espino 2006).
|Conservation Actions:||The persistence of this unique Andean fish depends strongly on our understanding of its essential habitat and the capacity to measure habitat-quality trends whether they are the result of management or the consequence of the environmental impact produced by human activities. More research is needed to understand the importance of subterranean water in the life cycle and resilience of A. ubidiai to habitat perturbations. It is not clear if populations are present within protected areas.|
|Citation:||Arguello, P. & Jimenez-Prado, P. 2016. Astroblepus ubidiai. The IUCN Red List of Threatened Species 2016: e.T46862A66234973.Downloaded on 18 March 2018.|