Post by surroundx on Oct 15, 2015 12:26:15 GMT
Scientific Name: Potamonautes dubius
Species Authority: (Brito-Capello, 1873)
Synonym(s):
Potamonautes bayonianus subspecies dubius Bott, 1955
Taxonomic Notes: Bott (1955) treated this taxon as the subspecies Potamonautes (Potamonautes) bayonianus dubius. Cumberlidge and Tavares (2006) argued that this taxon should properly be referred to as the valid species Potamonautes dubius.
Assessment Information [top]
Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Cumberlidge, N.
Reviewer(s): Daniels, S.R. (University of Stellenbosch), Darwall, W. (Freshwater Biodiversity Assessment Unit) and McIvor, A.
Justification:
This species is listed here as Data Deficient in view of the absence of recent information on its extent of occurrence, ecological requirements, population size, population trends, and long-term threats, and to doubts about its taxonomic status. Although P. dubius has been known to science for over 150 years it is still known from only a few specimens from one confirmed locality and was last collected in 1890. This taxon has not been represented in any of the material collected in the past 25 years in the vicinity of the Cunene River. In addition, there is a great deal of taxonomic uncertainty that surrounds this species, because it is only known with certainty from the type specimen because other literature and museum records of this species may be the result of misidentification. Without this taxonomic uncertainty, the species should probably be listed as at least Vulnerable, because it is known from only one location and has not been seen since 1890 despite surveys in the area over the last 25 years. It is possibly extinct.
Previously published Red List assessments:
2007 – Data Deficient (DD)
Geographic Range [top]
Range Description: Namibia and Angola: Kunene River. This species is endemic to the Cunene (Kunene) River and its tributaries in southwestern Angola and northern Namibia, where this river forms the border between these two countries. The Cunene River is more than 1,000 km long and has a catchment area of approximately 112,492 km². The course of the river includes a series of rapids, plus the Ruacana Falls and the Epupa (or Montenegro) Falls, after which its volume is reduced as it passes through the Namib Desert before emptying into the Atlantic Ocean. Because P. dubius is known only from a short stretch of this river its EOO is estimated to be less than 20,000 km², and its estimated area of occupancy is estimated to be about 2,000 km². More collections are necessary to establish the conservation status of this species.
Countries occurrence:
Native:
Angola (Angola, Angola); Namibia (Namibia (main part))
Estimated area of occupancy (AOO) - km2: <=2,000
Number of Locations: 1
Range Map: Click here to open the map viewer and explore range.
Population [top]
Population: There is no information available on the population size or abundance of this species.
Current Population Trend: Unknown
Additional data:
♦Population severely fragmented: No
Habitat and Ecology [top]
Habitat and Ecology: This is a river-living species.
Systems: Freshwater
Threats [top]
Major Threat(s): The major present and future threats to this species include habitat loss/degradation (human induced) due to human population increases.
Conservation Actions [top]
Conservation Actions: No conservation measures are known to be in place for this species.
Citation: Cumberlidge, N. 2008. Potamonautes dubius. The IUCN Red List of Threatened Species 2008: e.T64382A12765028. dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T64382A12765028.en . Downloaded on 15 October 2015.
Source: www.iucnredlist.org/details/64382/0
Species Authority: (Brito-Capello, 1873)
Synonym(s):
Potamonautes bayonianus subspecies dubius Bott, 1955
Taxonomic Notes: Bott (1955) treated this taxon as the subspecies Potamonautes (Potamonautes) bayonianus dubius. Cumberlidge and Tavares (2006) argued that this taxon should properly be referred to as the valid species Potamonautes dubius.
Assessment Information [top]
Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Cumberlidge, N.
Reviewer(s): Daniels, S.R. (University of Stellenbosch), Darwall, W. (Freshwater Biodiversity Assessment Unit) and McIvor, A.
Justification:
This species is listed here as Data Deficient in view of the absence of recent information on its extent of occurrence, ecological requirements, population size, population trends, and long-term threats, and to doubts about its taxonomic status. Although P. dubius has been known to science for over 150 years it is still known from only a few specimens from one confirmed locality and was last collected in 1890. This taxon has not been represented in any of the material collected in the past 25 years in the vicinity of the Cunene River. In addition, there is a great deal of taxonomic uncertainty that surrounds this species, because it is only known with certainty from the type specimen because other literature and museum records of this species may be the result of misidentification. Without this taxonomic uncertainty, the species should probably be listed as at least Vulnerable, because it is known from only one location and has not been seen since 1890 despite surveys in the area over the last 25 years. It is possibly extinct.
Previously published Red List assessments:
2007 – Data Deficient (DD)
Geographic Range [top]
Range Description: Namibia and Angola: Kunene River. This species is endemic to the Cunene (Kunene) River and its tributaries in southwestern Angola and northern Namibia, where this river forms the border between these two countries. The Cunene River is more than 1,000 km long and has a catchment area of approximately 112,492 km². The course of the river includes a series of rapids, plus the Ruacana Falls and the Epupa (or Montenegro) Falls, after which its volume is reduced as it passes through the Namib Desert before emptying into the Atlantic Ocean. Because P. dubius is known only from a short stretch of this river its EOO is estimated to be less than 20,000 km², and its estimated area of occupancy is estimated to be about 2,000 km². More collections are necessary to establish the conservation status of this species.
Countries occurrence:
Native:
Angola (Angola, Angola); Namibia (Namibia (main part))
Estimated area of occupancy (AOO) - km2: <=2,000
Number of Locations: 1
Range Map: Click here to open the map viewer and explore range.
Population [top]
Population: There is no information available on the population size or abundance of this species.
Current Population Trend: Unknown
Additional data:
♦Population severely fragmented: No
Habitat and Ecology [top]
Habitat and Ecology: This is a river-living species.
Systems: Freshwater
Threats [top]
Major Threat(s): The major present and future threats to this species include habitat loss/degradation (human induced) due to human population increases.
Conservation Actions [top]
Conservation Actions: No conservation measures are known to be in place for this species.
Citation: Cumberlidge, N. 2008. Potamonautes dubius. The IUCN Red List of Threatened Species 2008: e.T64382A12765028. dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T64382A12765028.en . Downloaded on 15 October 2015.
Source: www.iucnredlist.org/details/64382/0