Aylacostoma stigmaticum

[Melanie]

Extinct in the Wild due to building of the Yacyretá Dam on the Paraná River.



www.macn.gov.ar/0b_publico/15notas/ayla/ayla.htm

Only extant in captive holdings of Argentine Museum of Natural
Science. Increase in water depth changed the well-lit, clear bed with oxygenated water to dense growth of algae with muddy bottom.

[Peter]

From: oldwww.wii.gov.in/eianew/eia/dams%20and%20development/kbase/contrib/env242.pdf

Sedon, M. (2000). Molluscan Biodiversity and the impact of large dams. Prepared for Thematic Review II.1: Dams, ecosystem functions and environmental restoration. Report to IUCN Species Survival Commission. One of 126 contributing papers to the World Commission on Dams.

The surveys prior to the construction of the Parana Dam on the Parana river showed that there were endemic species present in the rapids. These species were threatened with extinction resulted from changes in the flow regime at Yacréta-Apipe rapids on the Parana River after the Parana Dam was constructed (Bertonatti, 1999). These species were taken into a captive breeding programme, and three taxa (Aylacostoma guaraniticum (Hylton-Scot, 1953) Aylacostoma chloroticum (Hylton-Scot, 1953) Aylacostoma stigmaticum (Hylton-Scot, 1953) are now extinct in the wild (Darrigan pers. comm; see Quintana, 1999; pers. Comm. For Action Plan).

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And from: intranet.iucn.org/webfiles/doc/archive/2001/IUCN850.pdf

Don E. McAllister, John F. Craig, Nick Davidson, Simon Delany and Mary Seddon. (2001). Biodiversity Impacts of Large Dams. Background Paper Nr. 1 Prepared for IUCN / UNEP / WCD). International Union for Conservation of Nature and Natural Resources and the United Nations Environmental Programme.

Table 3.4. Dam impacts on freshwater molluscs
Case studies: Yacyretá Reservoir (1600 km2. Parana River rapids, Argentina and Paraguay.
Biodiversity increases: None noted.
Biodiversity decreases: Species richness: 3 of 7 taxa from this group of prosobranchs in the river (genus Aylacostoma) are extinct in the Wild (EW). Only extant in captive holdings of Argentine Museum of Natural Science. Increase in water depth changed the well-lit, clear bed with oxygenated water to dense growth of algae with muddy bottom.
Source: Bertonatti (1999); Quintana (updates as pers. comm.).

[surroundx]

Excerpt from Google Scholar:

"Aylacostoma stigmaticum is listed by IUCN as “Extinct in the Wild” (Mansur, 2000); but could presently be categorized as extinct, as no specimen of this species has been reported to have survived in nature or captivity."

Source:

Vogler, Roberto E. (2013). The Radula of the Extinct Freshwater Snail Aylacostoma stigmaticum (Caenogastropoda: Thiaridae) from Argentina and Paraguay. Malacologia 56(1&2): 329-332.

[Melanie]

Jan 18, 2014 12:59:32 GMT surroundx said:

Source:

Vogler, Roberto E. (2013). The Radula of the Extinct Freshwater Snail Aylacostoma stigmaticum (Caenogastropoda: Thiaridae) from Argentina and Paraguay. Malacologia 56(1&2): 329-332.

This paper can be downloaded here:

www.academia.edu/Documents/in/Malacology

[surroundx]

Vogler, R. E., Beltramino, A. A., Strong, E. E., Rumi, A. and Peso, J. G. (2016). Insights into the Evolutionary History of an Extinct South American Freshwater Snail Based on Historical DNA. PLoS ONE 11(12): e0169191.

[koeiyabe]

www.iucnredlist.org/species/29613/9504747

[Sebbe]

Extinct in the wild: The precarious state of Earth’s most threatened group of species.

Collected from the wild into ex situ care in 1993 before filling of a reservoir in its native habitat. The last known wild population disappeared by 1996. This species became extinct outright in 2011 following a disease outbreak in ex situ facilities; the causal agent was unidentified but was suspected to be viral.

www.science.org/doi/10.1126/science.add2889