|Scientific Name:||Trionyx triunguis (Forskål, 1775)|
|Infra-specific Taxa Assessed:|
Aspidonectes aspilus Cope, 1865
Fordia africana Gray, 1869
Testudo triunguis Forskål, 1775
Trionyx aegyptiacus Geoffroy Saint-Hilaire, 1809
Trionyx egyptiacus Geoffroy Saint-Hilaire, 1809
Trionyx labiatus Bell, 1835
Trionyx mortoni Hallowell, 1844
Trionyx niloticus Gray, 1831
Trionyx triunguis ssp. rudolfianus Deraniyagala, 1948
|Taxonomic Source(s):||Fritz, U. and Havas, P. 2007. Checklist of chelonians of the world. Vertebrate Zoology 57(2): 149-368.|
Trionyx triunguis has been considered a single widespread, relatively uniform species for decades, with no subspecies or other taxonomic units recognized or proposed in recent years. Phylogeographic studies of regional variation have demonstrated different, partly conflicting results, but were based on generally limited sets of specimens and genetic markers (Gidis et al., 2011; Guclu et al., 2011, 2015; Shanas et al., 2012). However, there is still uncertainty as to whether Mediterranean and African populations may in fact represent genetically definable separate Management Units (O. Türkozan unpubl. data).
|Red List Category & Criteria:||Vulnerable A4bcd ver 3.1|
|Assessor(s):||van Dijk, P.P., Diagne, T., Luiselli, L., Baker, P.J., Turkozan, O. & Taskavak, E.|
|Reviewer(s):||Rhodin, A.G.J., Horne, B.D. & Branch, W.R.|
|Contributor(s):||Baha El Din, S., Chirio, L., Gbeintor, E., Iverson, J.B., Ngwava, J.M., Pauwels, O.S.G., Petrozzi, F., Segniagbeto, G., Trape, J.-F. & Werner, Y.L.|
|Facilitator/Compiler(s):||Rhodin, A.G.J., van Dijk, P.P.|
Populations in West Africa, representing about one-third of the overall historic range, have been in severe decline in recent decades with anecdotal indications that catch per unit effort has declined by 98% over the past two generations (estimated generation length of 20-30 years), and this trend is expected to continue. Its populations in Israel are small and fragmented, and considered Critically Endangered (under criterion C2a). In Egypt, the species has disappeared from the Nile below Lake Nasser. Populations in Central Africa are indicated to be in mild decline, while populations in northeastern Africa are understood to be stable. The Turkish population is expanding its range and is locally common; it may be threatened in Turkey but more information is needed. Overall, on balance this species has likely experienced well over 30% total population decline over its past two generations as a result of targeted exploitation and habitat degradation, and this trend is likely to continue, qualifying the species as Vulnerable based on criteria A4bcd. The West African populations likely warrant regional listing as Critically Endangered.
Trionyx triunguis ranges widely in Africa and the eastern Mediterranean. It occurs in the coastal regions of southern Turkey from Dalyan to Asi River, and in the Mediterranean coastal area of Israel from Tel Aviv northwards (Werner 2016). Records from Lebanon are known but current occurrence is uncertain. It has not been recorded from Syria, although vagrants probably occur there. Vagrants have been recorded from the Mediterranean coast as far north and west as Kos, Greece (Taskavak et al. 1999, Taskavak and Akçınar 2007). Trionyx triunguis has been successfully introduced into the Jordan River system in the north of Israel, including the remaining wetlands of Hula Lake (Werner 2016). In Africa, Trionyx occurs in the Nile River basin from Egypt upstream, in river basins in Eritrea, Ethiopia, Sudan, South Sudan, Somalia, and northern Kenya, and in coastal and inland river systems from the Senegal (Mauritania-Senegal) River throughout the Guinean forest zone of southern West Africa, including the Gambia, Guinea-Bissau, Mali, and Lake Chad, and with records extending from southern Central African Republic to the Cunene River on the Angola-Namibia border, including many localities in Gabon and some in Republic of Congo (Iverson 1992; Branch 1988, 2008; Boycott and Bourquin 2000; Spawls et al. 2002; Trape et al. 2012). Insufficient survey data are available to conclude whether the species is continuously distributed across these regions or occurs primarily in particular, restricted and fragmented areas only; the range is not connected between Lake Turkana and Somalia, but there is a possible record from the Somalia border region of Kenya. This species also has a scattered distribution along the southern coasts of West Africa (G. Segniagbeto and L. Luiselli et al. unpubl. data). Historically, Trionyx was known from the lower Nile below the Aswan Dam, but it is considered to be extinct there now (Spawls et al. 2002).
Native:Angola; Benin; Cameroon; Chad; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Egypt (Egypt (African part)); Equatorial Guinea; Eritrea; Ethiopia; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Israel; Kenya; Liberia; Namibia; Niger; Nigeria; Senegal; Sierra Leone; Somalia; South Sudan; Sudan; Togo; Turkey (Turkey-in-Asia); Uganda
|Range Map:||Click here to open the map viewer and explore range.|
Limited population data are available through most of the range of Trionyx triunguis.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
Trionyx triunguis inhabits fairly deep water in permanent lakes, rivers, estuaries, coastal lagoons and coastal waters, down to 80 m depth. It is highly tolerant of full seawater conditions for some time (Branch 1988, Baran and Atatur 1998, Taşkavak and Akçınar 2009). In Nigeria, it occurs in brackish water creeks and rivers, with mangroves (Luiselli et al. 2000). May use hot springs in Turkey. In Israel the quality of the habitat, and availability of nesting sites, varies with river fluctuations. It ranges from below sea-level to over 1,500 m (in Africa). In West Africa it is found in both savanna and forested zones (Trape et al. 2012). It is found along the seashore in Angola and at the mouths of larger rivers.
|Systems:||Terrestrial; Freshwater; Marine|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||20|
|Use and Trade:||
Trionyx triunguis is widely collected for consumption in the Sub-Saharan part of its distribution, mainly at local subsistence level (Branch 1988, Spawls et al. 2002). It is also hunted by fishermen for the bushmeat trade in West Africa (for instance, in southern Nigeria; Akani et al. 2001), but the trade level remains low because this species is very rarely encountered in the field. Nonetheless, the meat is highly valued, and the prices are considerable (G.C. Akani, E.A. Eniang, L. Luiselli unpubl. data). Large parts of the range are in areas predominantly occupied by Muslim communities, for whom this species is unsuitable for consumption.
Trionyx triunguis is widely collected for consumption in the Sub-Saharan part of its distribution, mainly at local subsistence level (Branch 1988, Spawls et al. 2002). It is also hunted by fishermen for the bushmeat trade in West Africa (for instance, in southern Nigeria: Akani et al. 2001), but the trade level remains low because this species is very rarely encountered in the field. Nonetheless, the meat is highly valued, and the prices are considerable (G.C. Akani, E.A. Eniang, L. Luiselli, unpubl. data).
Trionyx triunguis was listed on Appendix II by CITES in 2016, in addition to all other African softshells; the population in Ghana was also included in CITES Appendix III from 1976 to 2007. As far as can be ascertained, T. triunguis is fully protected from exploitation under the national wildlife laws of Congo, Cote D’Ivoire, Guinea-Bissau, Israel, Mali, Niger, Senegal, Sierra Leone, and Turkey, as well as being under partial protection in Chad (collection under permit only) and Ghana (trade is prohibited); legislative protective status for other countries could not be determined.
|Citation:||van Dijk, P.P., Diagne, T., Luiselli, L., Baker, P.J., Turkozan, O. & Taskavak, E. 2017. Trionyx triunguis. The IUCN Red List of Threatened Species 2017: e.T62256A96894956.Downloaded on 21 May 2018.|
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