Proteus anguinus 

Scope: Global & Europe
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Caudata Proteidae

Scientific Name: Proteus anguinus Laurenti, 1768
Common Name(s):
English Olm, Proteus
Siren anguina (Shaw,1802)
Taxonomic Source(s): Frost, D.R. 2014. Amphibian Species of the World: an Online Reference. Version 6 (27 January 2014). New York, USA. Available at: (Accessed: 27 January 2014).
Taxonomic Notes: Most populations are assigned to the subterranean subspecies Proteus anguinus anguinus. Unlike the nominate form, the genetically similar subspecies P.a. parkelj from Bela Krajina in Slovenia is pigmented and might represent a distinct species, although a recent genetic study suggests that the two subspecies are poorly differentiated at the molecular level and may not even warrant subspecies status (Goricki and Trontelt 2006).

Assessment Information [top]

Red List Category & Criteria: Vulnerable B2ab(ii,iii,v) ver 3.1
Year Published: 2009
Date Assessed: 2008-12-14
Assessor(s): Jan Willem Arntzen, Mathieu Denoël, Claude Miaud, Franco Andreone, Milan Vogrin, Paul Edgar, Jelka Crnobrnja Isailovic, Rastko Ajtic, Claudia Corti
Reviewer(s): Cox, N. and Temple, H.J. (Global Amphibian Assessment)
Listed as Vulnerable because its Area of Occupancy is less than 2,000 km2, its distribution is severely fragmented, and there is continuing decline in the extent and quality of its habitat, and presumably also in the number of mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:The species is restricted to subterranean aquatic habitats within the Dinaric Alps, ranging from southern Slovenia and adjoining north-east Italy through coastal Croatia and karst regions of Bosnia and Herzegovina. It has yet to be officially recorded in western parts of Montenegro despite considerable anecdotal evidence of its presence (Kalezic and Dzukic, 2001). The species has been introduced to a cave of the subterranean laboratory of the CNRS France in the Pyrenees (C. Miaud pers. comm.), and one of the north-eastern Italian populations (in the Vicenza area) was introduced in the 1800s (P. Edgar pers. comm.).
Countries occurrence:
Bosnia and Herzegovina; Croatia; Italy (Italy (mainland)); Slovenia
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There is little information available on the abundance of this species, but it is apparently most common in Slovenia and Croatia. A decline has been observed in the populations of Goriza (Italy) and Postojna (Slovenia) (Gasc et al. 1997). The number of individuals of the subspecies P. a. parkelj is very low.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:The species generally occurs in large subterranean aquatic karst systems formed in limestone and dolomite rocks, and may be found in cave entrances (especially during episodes of high rainfall and flooding) and abandoned mine workings. Many of the caves that the species occurs in are connected to rivers that run above ground for the first 50-100km and then disappear into the ground. Populations may be found close to the surface or as much as 300m underground depending on the thickness of the Karstic formation. The species is found in waters ranging from 5°C to 15°C. Animals feed on detritus and endemic cave invertebrates and hide in crevices or bottom sediment when disturbed. In contrast to the nominate subspecies, P. a. parkelj is found in warmer surface waters. The species is long-lived (they are not sexually mature until they are 12 years of age) and reproduce very slowly. Females lay approximately 70 individual eggs on the undersides of aquatic stones; however, in some cases the eggs are retained within the body and two fully formed young are produced.

Threats [top]

Major Threat(s): The main threats to this species are changes to the forested and pastoral land above the subterranean systems, largely through tourism, economic changes, and increasing water pollution. These changes have a direct influence on the quality of the habitat available to the species. The species is highly dependent on clean water, and is therefore very susceptible to pollution. Other localized threats to this species might include water abstraction and hydroelectric schemes. There is some illegal collection of this species for the pet trade, but the extent of this is unknown.

Conservation Actions [top]

Conservation Actions: It is listed on Appendix II of the Bern Convention, and on Annexes II* and IV of the EU Habitats Directive. It is recorded in the Slovenian National Red List and is protected by national legislation in many range states, e.g. Slovenia, Croatia and Italy. In Slovenia the species is present in caves, which are protected by national legislation, and much of the distribution of this species is within proposed national or international protected areas (Kocevski and Kraski regional parks; NATURA 2000 sites). In Italy it is found in the Riserva Naturale Regionale dei Laghi di Doberdò e Pietrarossa. The subspecies P. a. parkelj is in need of protection, as its habitat is limited to only a few holes in connection with subterranean networks in a very small geographic area.

Classifications [top]

5. Wetlands (inland) -> 5.18. Wetlands (inland) - Karst and Other Subterranean Hydrological Systems (inland)
15. Artificial/Aquatic & Marine -> 15.10. Artificial/Aquatic - Karst and Other Subterranean Hydrological Systems (human-made)
1. Land/water protection -> 1.1. Site/area protection
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.3. Habitat & natural process restoration
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management
3. Species management -> 3.1. Species management -> 3.1.2. Trade management
4. Education & awareness -> 4.3. Awareness & communications

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
1. Residential & commercial development -> 1.1. Housing & urban areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Residential & commercial development -> 1.3. Tourism & recreation areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.3. Agro-industry farming
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.5. Motivation Unknown/Unrecorded
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

6. Human intrusions & disturbance -> 6.1. Recreational activities
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.2. Species disturbance

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.3. Type Unknown/Unrecorded
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

9. Pollution -> 9.3. Agricultural & forestry effluents -> 9.3.4. Type Unknown/Unrecorded
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

♦  Pets/display animals, horticulture
 National : ✓  International : ✓ 

Bibliography [top]

1997. Atlas of Amphibians and Reptiles in Europe. Societas Europea Herpetologica & Museum National d'Histoire Naturelle, Paris.

Arnold, E.N. 2003. Reptiles and amphibians of Europe. Princeton University Press.

Arntzen, J.W. and Sket, B. 1996. Speak of the Devil: the taxonomic status of Proteus anguinus parkelj revisited (Caudata: Proteidae). Herpetozoa: 165-166.

Arntzen, J.W. and Sket, B. 1997. Morphometric analysis of black and white European cave salamanders, Proteus anguinus. Journal of Zoology: 699-707.

Böhme, W, Grossenbacher, K. and Thiesmeier, B. 1999. Handbuch der Reptilien und Amphibien Europas, band 4/I:Schwanzlurche (Urodela).

Briegleb, W. 1962. Zur Biologie und Ökologie des Grottenolms (Proteus anguinus Laurent, 1768). Zeitschrift fuer Morphologie und Ökologie der Tiere: 271-334.

Dolce, S. and Pichl, E. 1982. Le attuali conoscenze sulla diffusione de Proteus anguinus Laurent 1768 in territorio Italiano. Atti del Museo Civico di Storia Naturale di Trieste: 245-254.

Gorički, S. and Trontelj, P. 2006. Structure and evolution of the mitochondrial control region and flanking sequences in the European cave salamander Proteus anguinus. Gene, Volume 378, 15 August 2006, Pages 31-41.

Griffiths, R.A. 1996. Newts and Salamanders of Europe. Poyser Natural History, London.

Grillitsch, H. and Tiedemann, F. 1994. Die Grottenolm-Typen Leopold FITZINGERs (Caudata: Proteidae: Proteus). Herpetozoa: 139-148.

Hervant, F., Mathieu, J. and Durand, J.-P. 2000. Metabolism and circadian rhythm in the European blind salamander (Proteus anguinus) and a facultative cave dweller, the Pyrenean newt (Euproctus asper). Canadian Journal of Zoology: 1427-1432.

Hervant, F., Mathieu, J. and Durand, J.-P. 2001. Behavioural, physiological and metabolic responses to long-term starvation and refeeding in a blind cave-dwelling (Proteus anguinus) and a surface-dwelling (Euproctus asper) salamander. Journal of Experimental Biology: 269-281.

IUCN. 2009. European Species on the IUCN Red List. Available at: (Accessed: 22 June 2009).

Kalezic, M. and Dzukic, G. 2001. Amphibian status in Serbia and Montenegro (FR Yugoslavia). FrogLog 45.

Kletečki, E., Jalzić, B. and Rada, T. 1996. Distribution of the olm (Proteus anguinus, Laur.) in Croatia. Mémoires de Biospéologie: 227-231.

Sindaco, R., Doria, G., Razzetti, E. and Bernini, F. 2006. Atlas of Italian Amphibians and Reptiles\\Atlante Degli Anfibi E Dei Rettili D'Italia. Societas Herpetologica Italica - Edizioni Polistampa, Firenze.

Sket, B. 1997. Distribution of Proteus (Amphibia: Urodela: Proteidae) and its possible explanation. Journal of Biogeography: 263-280.

Sket, B. and Arntzen, J.W. 1994. A black, non-troglomorphic amphibian from the karst of Slovenia: Proteus anguinus parkelj n. ssp. (Urodela: Proteidae). Bijdragen tot de Dierkunde: 33-53.

Thorn, R. 1968. Les salamandres d'Europe, d'Asia, et d'Afrique du Nord. Éditions Paul Lechevalier, Paris.

Vogrin, M. 2002. Amphibians. In: Vogrin, M. (ed.), Nature in municipality Kidricevo, pp. 99-106. Municipality Kidricevo.

Vogrin, N. 1997. The status of amphibians in Slovenia. FrogLog 20.

Citation: Jan Willem Arntzen, Mathieu Denoël, Claude Miaud, Franco Andreone, Milan Vogrin, Paul Edgar, Jelka Crnobrnja Isailovic, Rastko Ajtic, Claudia Corti. 2009. Proteus anguinus. The IUCN Red List of Threatened Species 2009: e.T18377A8173419. . Downloaded on 21 August 2018.
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