Post by Melanie on Oct 18, 2010 11:01:07 GMT
Cambarellus chihuahuae has been assessed as Extinct. The sites from which this species was previously known, have now dried up and the only remaining spring in the area contains no crayfish. There is no other suitable habitat in the area as a result of excessive groundwater abstraction for agriculture. There have been a number of targeted surveys for this species.
Geographic Range [top]
Range Description: Until recently, this species was known from the type locality, Ojo de Carbonera spring, 4.3 km south of Ejido Rancho Nuevo, approximately 57.6 km west of Villa Ahumada, Chihuahua, Mexico, and three other springs within 3 km of Ojo de Carbonera (Hobbs 1980). These springs were highly discontinuous, meaning the distribution of this species was highly fragmented (C. Pedraza-Lara pers. comm. 2010). A recent survey for this species found the type locality of this species, and several other former locations, to be completely devoid of water in 2009 (F. Alvarez pers. comm. 2010). A single spring in the area still contained water but was not found to support any crayfish after extensive searches (F. Alvarez pers. comm. 2010).
Countries:
Regionally extinct:
Mexico (Chihuahua)
Population [top]
Population: Fewer than 100 specimens have been collected of this species (F. Alvarez pers. comm. 2009). After targeted surveys of this species, no new specimens were found, and it is believed to be Extinct (F. Álvarez pers. comm 2010) .
Population Trend: Unknown
Habitat and Ecology [top]
Habitat and Ecology: The type locality was a clear shallow spring, 10 cm deep and 1 - 2.5 m wide, which flows at a moderate rate over sand and gravel substrate, with sparse vegetation consisting of filamentous algae and submerged grass (Hobbs 1980). There is no suitable habitat surrounding the type locality, as the region is very arid (M. López-Mejía., F. Alvarez. and C. Pedraza-Lara pers. comm. 2009). This species was thought to co-occur with the Endangered pupfish Ciprynodon fontinalis (C. Pedraza-Lara pers. comm. 2010).
Systems: Freshwater
Threats [top]
Major Threat(s): Ojo de Carbonera spring is threatened by increased pumping of groundwater for irrigation, which has already resulted in the failure of other spring flows in nearby areas (Echelle et al. 2003). An increased level of dessication has also been reported from the area once occupied by this species (C. Pedraza-Lara pers. comm. 2010). This seems to have led to the complete dessication of most, if not all, of the springs which formerly supported populations of this species (F. Alvarez pers. comm. 2010), while the agricultural industry responsible for this water abstraction has now collapsed in the area owing to a lack of groundwater.
Conservation Actions [top]
Conservation Actions: There are no species-specific conservation measures in place for this species.
www.iucnredlist.org/details/153621/0
Geographic Range [top]
Range Description: Until recently, this species was known from the type locality, Ojo de Carbonera spring, 4.3 km south of Ejido Rancho Nuevo, approximately 57.6 km west of Villa Ahumada, Chihuahua, Mexico, and three other springs within 3 km of Ojo de Carbonera (Hobbs 1980). These springs were highly discontinuous, meaning the distribution of this species was highly fragmented (C. Pedraza-Lara pers. comm. 2010). A recent survey for this species found the type locality of this species, and several other former locations, to be completely devoid of water in 2009 (F. Alvarez pers. comm. 2010). A single spring in the area still contained water but was not found to support any crayfish after extensive searches (F. Alvarez pers. comm. 2010).
Countries:
Regionally extinct:
Mexico (Chihuahua)
Population [top]
Population: Fewer than 100 specimens have been collected of this species (F. Alvarez pers. comm. 2009). After targeted surveys of this species, no new specimens were found, and it is believed to be Extinct (F. Álvarez pers. comm 2010) .
Population Trend: Unknown
Habitat and Ecology [top]
Habitat and Ecology: The type locality was a clear shallow spring, 10 cm deep and 1 - 2.5 m wide, which flows at a moderate rate over sand and gravel substrate, with sparse vegetation consisting of filamentous algae and submerged grass (Hobbs 1980). There is no suitable habitat surrounding the type locality, as the region is very arid (M. López-Mejía., F. Alvarez. and C. Pedraza-Lara pers. comm. 2009). This species was thought to co-occur with the Endangered pupfish Ciprynodon fontinalis (C. Pedraza-Lara pers. comm. 2010).
Systems: Freshwater
Threats [top]
Major Threat(s): Ojo de Carbonera spring is threatened by increased pumping of groundwater for irrigation, which has already resulted in the failure of other spring flows in nearby areas (Echelle et al. 2003). An increased level of dessication has also been reported from the area once occupied by this species (C. Pedraza-Lara pers. comm. 2010). This seems to have led to the complete dessication of most, if not all, of the springs which formerly supported populations of this species (F. Alvarez pers. comm. 2010), while the agricultural industry responsible for this water abstraction has now collapsed in the area owing to a lack of groundwater.
Conservation Actions [top]
Conservation Actions: There are no species-specific conservation measures in place for this species.
www.iucnredlist.org/details/153621/0
