|Scientific Name:||Cyclanorbis elegans (Gray, 1869)|
Baikiea elegans Gray, 1869
Cyclanorbis oligotylus Siebenrock, 1902
|Taxonomic Source(s):||Fritz, U. and Havas, P. 2007. Checklist of chelonians of the world. Vertebrate Zoology 57(2): 149-368.|
|Red List Category & Criteria:||Critically Endangered A2bcd+4bcd ver 3.1|
|Assessor(s):||Baker, P.J., Luiselli, L. & Diagne, T.|
|Reviewer(s):||Rhodin, A.G.J. & van Dijk, P.P.|
|Contributor(s):||Trape, J.-F., Chirio, L., Petrozzi, F. & Segniagbeto, G.|
|Facilitator/Compiler(s):||van Dijk, P.P. & Rhodin, A.G.J.|
No specimens of Cyclanorbis elegans have been confirmed during extensive surveys throughout its wide range in recent decades; only in a few places could fishermen describe this large, distinctive species (Baker et al. 2015). It appears that C. elegans has disappeared from several, if not most, of the major river systems that the species is historically known to have inhabited. The species has possibly disappeared completely from western Africa, with the greatest likelihood of a (likely depleted) population surviving in the middle Nile of Sudan and South Sudan. Overall, assuming a generation time of 25 years, the species has likely declined by over 80% over the past two generations, and the fishing and collecting pressures that depleted this large riverine species are likely to continue and possibly become more intensive. Thus the species qualifies as Critically Endangered under criteria A2bcd and A4bcd. Cyclanorbis elegans was last assessed in 1996, as Near Threatened.
|Previously published Red List assessments:|
Cyclanorbis elegans is known from localized disjunct occurrences in Ghana and northern Togo, in central Nigeria, the Niger river, southern Chad, northern Central African Republic, and the White Nile basin (including the Sobat) of South Sudan and Sudan (Iverson 1992, Gramentz 2008, Baker et al. 2015). Occurrence in headwaters or intervening countries, such as in Benin or Ethiopia, is plausible but remains unconfirmed. A historic record exists from Lake Volta, before the river was dammed. Chirio and Ineich (2006) regarded the record of C. elegans by Joger (1990) in Central African Republic as potentially misidentified C. senegalensis, but occurrence in the Ouam valley is possible (Sub-Saharan WS, 2013). Gramentz (2008) questioned the record(s) from Cameroon (Chirio and LeBreton 2007), but photos of a specimen collected there by Chirio and LeBreton (2007) confirm the species' occurrence in Cameroon (Baker et al. 2015).
Native:Cameroon; Central African Republic; Chad; Ghana; Nigeria; South Sudan; Sudan; Togo
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Cyclanorbis elegans is considered very rare in West Africa (Trape et al. 2012, Baker et al. 2015). Its distribution is fragmented and no detailed population data are available (Gramentz 2008, Baker et al. 2015). Recent inquiries into the distribution and status of the species (Baker et al. 2015) suggest that the species has become extremely rare across most of its range, with the possible exception of the middle Nile in South Sudan and Sudan. It is exceedingly rare in Nigeria, where it has a very narrow distribution, apparently concentrated around Lokoja (Akani, Luiselli, Eniang, unpubl. data). In Togo, it is also extremely rare: only a few museum specimens are known. The species is known to occur at Sansanné-Mango, Togo, along the Oti River (Segniagbeto et al. 2014). A few specimens are known from Central African Republic, possibly surviving in the Ouam valley (Sub-Saharan WS 2013).|
Very few observations have been recorded in recent decades from anywhere in its range; generally it is not known by fishermen, therefore it is likely to have disappeared long ago. In the Nile of South Sudan, interviewed fishermen knew about it, but no evidence of recent specimens could be found (Baker et al. 2015). Studies on its distribution have been ongoing in Nigeria (by L. Luiselli, G.C. Akani, E.A. Eniang, N. Ebere, F. Petrozzi) and in Togo (L. Luiselli, F. Petrozzi, G.H. Segniagbeto); preliminary data confirm that the species is very rare, and possibly on the brink of extinction in these countries.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
While no reliable habitat information is available for C. elegans, it is generally understood that this is a species that inhabits large rivers with muddy substrates (Gramentz 2008, Trape et al. 2012, Baker et al. 2015). For instance, a single individual was captured some years ago in the River Niger, not far from Lokoja (Akani, Luiselli, Eniang, unpubl. data). No specific information is available on its diet (Gramentz 2008). The largest recorded animal, a male, was 67.6 cm straight carapace length (SCL) and weighed 20.4 kg; the largest recorded female was 51.6 cm SCL and 11.3 kg (McCord, in Gramentz 2008). Animals may reach perhaps up to 70 cm SCL (Gramentz 2008, Trape et al. 2012). No information on age or size at maturity, reproductive output, or longevity appear available; by analogy with other large riverine softshell turtle species, a generation time of 25 years is estimated.
|Generation Length (years):||25|
|Use and Trade:||
Human consumption of large softshell turtles is widespread and poses a serious threat to C. elegans (Gramentz 2008, Luiselli 2009, Baker et al. 2015). Bari fishermen in South Sudan consume the flesh of both Cyclanorbis species, including the cartilaginous portions of the shell. About half of the museum specimens utilized in a description of skeletal morphology had been harvested and butchered. In South Sudan, turtle eggs are opportunistically collected by pastoralists who bring their cattle to feed on the “toic” grasslands that form when the floodwaters of the Nile recede (Baker et al. 2015). Eggs of large softshells (e.g., Trionyx triunguis) are consumed in southern Nigeria (Luiselli et al. unpubl. data); it is likely that the same applies to any remaining Nigerian populations of C. elegans. Collection for the pet trade is not currently considered a threat to the species, as it has not been recently reported to have been exported from Togo, Ghana, or Benin, which are the main export countries of reptiles for West Africa (examination of CITES dataset).
Available information (Gramentz 2008, Baker et al. 2015) indicates that collection of C. elegans for local consumption occurs and may be widespread and intensive if any significant populations remain anywhere, as the animals are large and their meat is highly esteemed. Old historic records exist from the Lake Volta area before the river was dammed to create the lake; the species may have been impacted by conversion of rivers to reservoirs in Ghana and elsewhere (Sub-Saharan WS, 2013).
Riverine turtles, like C. elegans, face similar pressures of extensive habitat destruction by sand mining, damming, channelization, and pollution (Baker et al. 2015). While the habitat of C. elegans has been mostly untouched by industrial development, planned hydrologic interventions upstream from the Sudd wetlands of South Sudan could have drastic consequences for C. elegans and other species that rely on the natural function of this flood-pulse ecosystem.
Cyclanorbis elegans is not protected or regulated under international legislation at present. It is not known with certainty to occur in secure protected areas.
Surveys of the distribution, population status and population trends of Cyclanorbis elegans are urgently required, including descriptions and evaluations of exploitation and other observed and potential threats, across the range and with emphasis on Sudan and South Sudan. Conservation measures, possibly including establishment of protected areas and measures to manage targeted capture and reduce bycatch in fisheries, are urgently needed.
|Citation:||Baker, P.J., Luiselli, L. & Diagne, T. 2016. Cyclanorbis elegans. The IUCN Red List of Threatened Species 2016: e.T6004A3086539.Downloaded on 24 March 2018.|