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Apalone spinifera atra, 021

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Apalone spinifera atra (Webb and Legler 1960) –
Black Spiny Softshell Turtle, Cuatrociénegas Softshell,
Tortuga Concha Blanda, Tortuga Negra de Cuatrociénegas

Adrián Cerdá-Ardura1, Francisco Soberón-Mobarak 2,
Suzanne E. McGaugh
3, and Richard C. Vogt4

1Romero 93 Col. Niños Heroes, C.P. 03440, Mexico D.F. Mexico [[email protected]];
2Xavier Sorondo 210 Col. Iztaccihuatl, C.P. 03520, Mexico D.F. Mexico [[email protected]];
3Department of Ecology, Evolution, and Organismal Biology,
Iowa State University, Ames, Iowa 50011 USA [[email protected]];
4CPBA/INPA, Caixa Postal 478, Petropolis,
Manaus, Amazonas 69011-970 Brazil [[email protected]]


Summary. – Apalone spinifera atra (Family Trionychidae), endemic to the Cuatrociénegas Basin of Coahuila, Mexico, is an enigmatic and severely threatened softshell turtle. On the basis of morphology, it has been regarded as a full species (Apalone ater), but by phylogenetic molecular analyses it is currently considered a subspecies of A. spinifera. The discovery of color morphs correlated to substrate coloration in different localities and the recognition of hybridization between A. s. atra and A. s. emoryi have led to additional taxonomic uncertainty. In addition, A. s. atra has a very restricted distribution with an apparently small population size that is also being affected by genetic introgression from A. s. emoryi. These factors, combined with recent anthropogenic draining and alteration of its limited freshwater habitats, have placed A. s. atra at very high risk for extinction in the near future, if careful conservation actions are not taken immediately. In addition, a lack of information about its ecology has made its relationships and survival prospects more difficult to discern. It is listed as Critically Endangered by the IUCN Red List, included on Appendix I of CITES, listed as Endangered by US ESA, and as a Species of Special Concern by the Mexican Secretaría de Medio Ambiente y Recursos Naturales.

Distribution. – Mexico. Restricted to the Cuatrociénegas Basin, Coahuila.

Synonymy. – Trionyx ater Webb and Legler 1960, Trionyx spinifer ater

, Trionyx spiniferus ater, Apalone spinifera ater, Apalone ater, Apalone spiniferus ater, Apalone spinifera atra, Apalone atra .


Status. – IUCN 2007 Red List: Critically Endangered (CR A1ace, B1+2c) (assessed 1996, needs updating); CITES: Appendix I; US ESA: Endangered; Mexico: Species of Special Concern.



Cerdá-Ardura, A., Soberón-Mobarak, F., McGaugh, S.E., and Vogt, R.C. 2008. Apalone spinifera atra (Webb and Legler 1960) – black spiny softshell turtle, Cuatrociénegas softshell, tortuga concha blanda, tortuga negra de Cuatrociénegas. In: Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., and Iverson, J.B. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs No. 5, pp. 021.1-021.4, doi:10.3854/crm.5.021.atra.v1.2008, //iucn-tftsg.org/cbftt/.

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Apalone spinifera atra from Tío Cándido, Cuatrociénegas Basin, Coahuila, Mexico.
Photo by Suzanne E. McGaugh.



Distribution of Apalone spinifera atra in northeastern Mexico, restricted to the Cuatrociénegas Basin in Coahuila. Red points = museum and literature occurrence records of atra and atra-emoryi intergrades based on published records and authors’ data; green shading = projected distribution based on authors’ data for atra

and atra-emoryi intergrades.