Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Cypriniformes Cyprinidae

Scientific Name: Chondrostoma holmwoodii
Species Authority: (Boulenger, 1896)
Common Name(s):
English Eastern Aegean Nase
Capoeta holmwoodii Boulenger, 1896
Taxonomic Source(s): Eschmeyer, W.N. (ed.). 2014. Catalog of Fishes. Updated 10 March 2014. Available at: http://

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2c; B2ab(i,ii,iii,iv,v) ver 3.1
Year Published: 2014
Date Assessed: 2013-03-05
Assessor(s): Freyhof, J.
Reviewer(s): Ekmekçi, F., Küçük, F., Sarı, H. & Smith, K.
This species is known from the Küçük Menderes, Tahtalı (Izmir), Gediz and Bakır drainages in Western Anatolia, Turkey. It is expected to have vanished from Küçük Menderes drainage more than 10 years ago due to massive levels of water abstraction. While this species still has a relatively wide range, threats (water extraction and pollution) are very intense in the area and the species only occurs in a few sites that have enough water between dams and polluted areas, giving the species an estimated area of occupancy (AOO) of 600 km² (it occurs in an estimated 300 km of stream length). It is expected to exist in more then five but less then 10 independent subpopulations (which are treated as locations based on the threat of water abstraction). It is also believed to still be declining due to the intense threats. While there is no information on rate of population decline, it is suspected that over the past 10 years it has declined by at least 30% (but less than 50%). It is therefore assessed as Vulnerable.
Previously published Red List assessments:
2006 Data Deficient (DD)
1996 Vulnerable (VU)

Geographic Range [top]

Range Description: The species is known from the Küçük Menderes, Tahtalı (Izmir), Gediz and Bakır drainages in Western Anatolia, Turkey. \It is believed to have vanished from Küçük Menderes drainage.
Countries occurrence:
Turkey (Turkey-in-Asia)
Estimated area of occupancy (AOO) - km2: 600
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2:
Continuing decline in extent of occurrence (EOO): Yes
Number of Locations: 6-10
Continuing decline in number of locations: Yes
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: No data are available on population trends. It is believed to be declining due to many threats across its range. The species is expected to have vanished from Küçük Menderes drainage, which is now desiccated in its upper reaches and heavily polluted in its lower reaches. It is very rare in other rivers which are massively polluted in the main streams and full of dams in the headwaters.
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Yes

Habitat and Ecology [top]

Habitat and Ecology: Medium sized streams to large rivers with rocky or gravel substrate and swift to moderately fast current.
Systems: Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Water pollution and extraction are the major threats to this species. It also suffers from many dam constructions across its range, and from reduced rainfall due to climate change.

Conservation Actions [top]

Conservation Actions: None known to be in place.

Citation: Freyhof, J. 2014. Chondrostoma holmwoodii. The IUCN Red List of Threatened Species 2014: e.T4787A19006425. . Downloaded on 14 October 2015.
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