Trichonia trichonica 

Scope: Global, Europe & Mediterranean
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Littorinimorpha Hydrobiidae

Scientific Name: Trichonia trichonica Radoman, 1973

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B2ab(i,iii) ver 3.1
Year Published: 2011
Date Assessed: 2009-11-27
Assessor(s): Hauffe, T., Albrecht, C. & Schreiber, K.
Reviewer(s): Falniowski, A., Radea, K., Régnier, C., Seddon, M., Cuttelod, A. & Nichols, C.
Contributor(s): Radea, K. & Régnier, C.
Trichonia trichonica is described from two locations (Lake Trichonis and Lake Pamvotis), but within the last 30 years no single specimen or even shells of this species were recorded in Lake Trichonis (Albrecht et al. pers. comm. 2009) and so it is considered lost from this location. Based on the Lake Pamvotis spring location it has an area of occupancy of 4 km² and there is a decline in the habitat quality caused by pollution. Threats come from changing water quality with increasing nitrate content following water draining into the lake from streams carrying agricultural fertilizers used on the land and inflow of sewage. It is therefore considered as Critically Endangered (CR B2ab(i,iii)).

Regnier et al. (2009) suggested that this species was extinct, based on information in Szarowska and Falniowski, A. (2004) but this was an error, as there are other records from Lake Pamvotis suggesting there is another location (Frogley and Preece 2007), so as such, these sightings review investigation, as do other small lakes in the region.

This species is also assessed at regional level:

EU27 regional assessment: Critically Endangered (CR B2ab(i,iii)) at the level of the 27 member States of the European Union
European regional assessment: Critically Endangered (CR B2ab(i,iii))
Mediterranean regional assessment: Critically Endangered (CR B2ab(i,iii))

Geographic Range [top]

Range Description:This species is endemic to Greece. Radoman (1983) reported populations from the north-eastern shore of Lake Trichonis near Mirtia. Schütt (1980) described it from the south coast, hitherto this species could not be found during recent surveys (Albrecht et al. 2009). It was recently described from Lake Pamvotis (Frogley and Preece 2007).
Countries occurrence:
Greece (Greece (mainland))
Additional data:
Estimated area of occupancy (AOO) - km2:4
Continuing decline in extent of occurrence (EOO):Yes
Number of Locations:1
Lower depth limit (metres):30
Upper depth limit (metres):5
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The population status of this species is unknown. Radoman (1983) reported populations from the northeastern shore near Mirtia and Schütt (1980) from the south coast, hitherto this species could not be found during recent surveys (Albrecht et al. 2009).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This sublittoral species is restricted to rocky banks.
Continuing decline in area, extent and/or quality of habitat:Yes

Use and Trade [top]

Use and Trade: This species is not utilized.

Threats [top]

Major Threat(s): Heavy pollution related to intensive agriculture practice (Lake Trichonis) and settlements (Lake Pamvotis) in the neighbouring area, is responsible for the eutrophication of the lakes. In relation with this, the biofilm (algae) present on the hard substrate is changing, diminishing habitat and food availability for this small gastropod. Herbicides might also impact diatomae communities, which are the major food source for this snail.

Conservation Actions [top]

Conservation Actions: Lake Trichonis is a Natura 2000 site. Fertilizers, pesticides and herbicides use for agriculture purposes, as well as sewage, need to be drastically reduced. Habitat monitoring is recommended due to the effects of agricultural and domestic pollution.


Citation: Hauffe, T., Albrecht, C. & Schreiber, K. 2011. Trichonia trichonica. The IUCN Red List of Threatened Species 2011: e.T155560A4798193. . Downloaded on 18 September 2018.
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