Margarya yangtsunghaiensis 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Architaenioglossa Viviparidae

Scientific Name: Margarya yangtsunghaiensis
Species Authority: Tschang & Tsi, 1949

Assessment Information [top]

Red List Category & Criteria: Critically Endangered () A2a; B1ab(i,ii,iii,iv,v) ver 3.1
Year Published: 2009
Date Assessed: 2008-03-28
Assessor(s): Jiang, Y., McIvor, A., Aldridge, D., Di, L., Yueing, L. & Min, W.
Reviewer(s): Smith, K., McIvor, A. & Seddon, M.
Margarya yangtsunghaiensis has not seen since 1949 despite recent surveys in 2006 by Du Lina. The species may already be extinct, but it may be that further surveys may still find some surviving individuals. Currently it is assessed as Critically Endangered as there has been a decline of at least 80%, based on the fact that none have been found where they were previously recorded. Also it has a small possible extent of occurrence since it was found in only one lake with a surface area of 32 km², and there has been a decline in its known range, quality of habitat, and population size.
Date last seen: 1949

Geographic Range [top]

Range Description: This species is (or was) endemic to Lake Yangtsunghai (32 km²) in Yunnan Province, China. The species has not been found since 1949.
Countries occurrence:
Possibly extinct:
China (Yunnan)
Estimated area of occupancy (AOO) - km2: 32
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2: 32
Continuing decline in extent of occurrence (EOO): Yes
Number of Locations: 1
Continuing decline in number of locations: Yes
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The species has not been recorded since 1949; it may already be extinct.
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Yes

Habitat and Ecology [top]

Habitat and Ecology: This snail was recorded from deep areas in the lake.
Systems: Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes

Threats [top]

Major Threat(s): The main threat to this species, if it is still extant, is ongoing pollution of the lake. The species is not harvested. When surveyed in 2006, no live specimens were found from the previous site in the lake where the species was known to occur. It was last seen in 1949.

Conservation Actions [top]

Conservation Actions: No conservation measures are in place for this species. More surveys are required to confirm whether the species is still extant in the lake. There also needs to be awareness raising about this species among local people, and pollution levels in the lake need to be reduced.

Citation: Jiang, Y., McIvor, A., Aldridge, D., Di, L., Yueing, L. & Min, W. 2009. Margarya yangtsunghaiensis. The IUCN Red List of Threatened Species 2009: e.T168215A6467233. . Downloaded on 27 November 2015.
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