Pachnodus niger

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	MOLLUSCA	GASTROPODA	STYLOMMATOPHORA	CERASTIDAE

Scientific Name:	Pachnodus niger
Species Authority:	(Dufo, 1840)
Taxonomic Notes:	Two subspecies have been described: P. n. niger (Dufo, 1840) and P. n. subfuscus Gerlach, 1994.

Assessment Information [top]

Red List Category & Criteria:	Endangered B1ab(iii)+2ab(iii) ver 3.1
Year Published:	2009
Assessor/s:	Gerlach, J.
Reviewer/s:	Miller, R.M., Pollock, C.M. & Seddon, M.
Contributor/s:
Justification: This species has a restricted range: it's EOO is 300 km² and its AOO is 8 km²; it is known from only 2 locations. Throughout this area, invasive species (e.g. Cinnamomum verum trees) are causing ongoing habitat deterioration. Fortunately, population are currently stable, though vulnerable to further habitat degradation.

Geographic Range [top]

Range Description:	This snail is endemic to the Seychelles. Its extent of occurence (EOO) is estimated to be 300 km², and it has a total area of occupancy (AOO) of just 8 km². The two subspecies are distributed on two different islands: P. n. niger on north Mahé island (AOO = 5 km²) and P. niger subfuscus on Praslin island (AOO = 3 km²).
Countries:	Native: Seychelles (Seychelles (main island group))
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	In 2005, the total population was estimated at 8,000 adults: 5,000 of the subspecies P. n. niger and 3,000 of the subspecies P. n. subfuscus.
Population Trend:	Stable

Habitat and Ecology [top]

Habitat and Ecology:	An arboreal species found in forest habitats, P. n. niger inhabits high forest while P. n. subfuscus is found in palm forest.
Systems:	Terrestrial

Threats [top]

Major Threat(s):	This snail species is threatened by habitat degradation, due to invasive alien species (e.g., Cinnamomum verum) which directly impact this snail's habitat. In the past, small-scale farming caused declines in habitat quality. P. n. niger has also hybridized with P. velutinus. Fortunately, however, the hybrid form has not expanded into the range of P. n. niger.

Major Threat(s):

This snail species is threatened by habitat degradation, due to invasive alien species (e.g., Cinnamomum verum) which directly impact this snail's habitat. In the past, small-scale farming caused declines in habitat quality. P. n. niger has also hybridized with P. velutinus. Fortunately, however, the hybrid form has not expanded into the range of P. n. niger.

Conservation Actions [top]

Conservation Actions:	P. n. subfuscus is present in the Praslin National Park.

Conservation Actions:

P. n. subfuscus is present in the Praslin National Park.

Citation:	Gerlach, J. 2009. Pachnodus niger. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 19 June 2013.
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