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Published: 2017-09-11

Who is the red-bearded snake, anyway? Clarifying the taxonomic status of Chironius pyrrhopogon (Wied, 1824) (Serpentes: Colubridae)

Departamento de Biologia e Zoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Avenida Fernando Corrêa da Costa, 2367, Boa Esperança, CEP 78060-900, Cuiabá, MT, Brazil Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, Rua Professor Artur Riedel, 275, Jardim Eldorado, CEP 09972-270, Diadema, SP, Brazil
Departamento de Biologia e Zoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Avenida Fernando Corrêa da Costa, 2367, Boa Esperança, CEP 78060-900, Cuiabá, MT, Brazil
Departamento de Zoologia, Centro de Biociências, Universidade Federal de Pernambuco, Av. Professor Moraes Rego, s/n., Cidade Universitária, CEP 50670-901, Recife, PE, Brazil
Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, Rua Professor Artur Riedel, 275, Jardim Eldorado, CEP 09972-270, Diadema, SP, Brazil
Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Caixa Postal 11.461, CEP 05422-970, São Paulo, SP, Brazil
Reptilia Coloration features Chironius exoletus Atlantic Forest Rio Benevente Dietary sequestration


We provide morphological data supporting the allocation of Chironius pyrrhopogon (Wied, 1824) in the synonymy of C. exoletus, proposed earlier in the literature without proper justification. Besides the historical (literature) data, we also examined 155 Chironius specimens previously identified as C. exoletus, C. pyrrhopogon and C. quadricarinatus that could possibly fit the diagnosis and distribution of Wied’s specimens, and performed statistical tests to assess potentially informative variations in the sample. In addition, we concluded that the color features associated with C. pyrrhopogon are by no means diagnostic of a unique entity. Nonetheless, although apparently present at random in some Chironius species in the Atlantic Forest, we suggest that the reddish-brown spots are possibly linked to other phenomena involving co-evolutionary interactions with anuran potential preys.



  1. Bailey, J.R. (1955) The snakes of the genus Chironius in Southeastern South America. Occasional Papers Museum of Zoology University of Michigan, 571, 1–21.

    Boie, F. (1827) Bemerkungen über Merrem's Versuch eines Systems der Amphibien. Marburg. 1820. Erste Lieferung: Ophidier. Isis von Oken, 20, 508–566 [columns].

    Dixon, J.R., Wiest Jr., J.A. & Cei, J.M. (1993) Revision of the Neotropical snake genus Chironius Fitzinger (Serpentes, Colubridae). Museo Regionale di Scienze Naturali, 13, 1–279.

    Donoso-Barros, R. (1969) Contribución al conocimiento del genero Chironius (Serpentes: Colubridae). Boletin de la Sociedad de Biologia de Concepción, 41, 189–197.

    Dowling, H.G. (1951) A proposed standard system of counting ventral in snakes. British Journal of Herpetology, 1 (5), 97–99.

    Fernandes, D.S. & Hamdan, B. (2014) A new species of Chironius Fitzinger, 1826 from the state of Bahia, Northeastern Brazil (Serpentes: Colubridae). Zootaxa, 3881 (6), 563–575.

    Fitzinger, L.J. (1826) Neue Classification der Reptilien nach ihren Natürlichen Verwandtschaften nebst einer Verwandtschafts-Tafel und einem Verzeichnisse der Reptilien-Sammlung des K.K. Zoologisch Museums zu Wien. J.G. Heubner, Viena, 66 pp.

    Gans, C. (1960) Notes on a herpetological collecting trip through the southeastern lowlands of Bolivia. Annals of the Carnegie Museum, 35, 283–314.

    Hamdan, B. & Fernandes, D.S. (2015) Taxonomic revision of Chironius flavolineatus (Jan, 1863) with description of a new species (Serpentes: Colubridae). Zootaxa, 4012 (1), 97–119.

    Hollis, J.L. (2006) Phylogenetics of the genus Chironius Fitzinger, 1826 (Serpentes, Colubridae) based on morphology. Herpetologica, 62 (4), 435–453.[435:potgcf];2

    Hutchinson, D.A., Mori, A., Savitzky, A.H., Burghardt, G.M., Wu, X., Meinwald, J. & Schroeder, F.C. (2007) Dietary sequestration of defensive steroids in nuchal glands of the Asian snake Rhabdophis tigrinus. Proceedings of the National Academy of Sciences, 104 (7), 2265–2270.

    ICZN [International Commission on Zoological Nomenclature] (1999) International Code of Zoological Nomenclature. The International Trust for Zoological Nomenclature, Padova, xxix + 306 pp.

    Jan, G. (1863) Elenco sistematico degli Ofidi Descritti e disegnati per l'Iconografia generale. Tipografia A. Lombardi, Milano, vii + 143 pp.

    Jared, C., Mailho-Fontana, P.L., Antoniazzi, M.M., Mendes, V.A., Barbaro, K.C., Rodrigues, M.T. & Brodie Jr., E.D. (2015) Venomous frogs use heads as weapons. Current Biology, 25 (16), 2166–2170.

    Klaczko, J., Montingelli, G.G. & Zaher, H. (2014) A combined morphological and molecular phylogeny of the genus Chironius Fitzinger, 1826 (Serpentes: Colubridae). Zoological Journal of the Linnean Society, 171 (3), 656–667.

    Kok, P.J.R. (2010) A new species of Chironius Fitzinger, 1826 (Squamata: Colubridae) from the Pantepui region, northeastern South America. Zootaxa, 2611, 31–44.

    Kumar, A. (2010) A tragic loss: fire at Instituto Butantan, Brazil. Toxicon, 56, 1528–1529.

    Lema, T. de, Vieira, M.I. & Araújo, M.L. (1984) Fauna reptiliana do norte da grande Porto Alegre, Rio Grande do Sul, Brasil. Revista Brasileira de Zoologia, 2, 203–227.

    Linnaeus, C. (1758) Systema nature per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Holmiae, Laurentii Salvii, 824 pp.

    Lix, L.M., Keselman, J.C. & Keselman, H.J. (1996) Consequences of assumption violations revisited: A quantitative review of alternatives to the one-way analysis of variance F test. Review of Educational Research, 66, 579–619.

    Marques, O.A.V. & Sazima, I. (2003) Ontogenetic color changes may strengthen suggestion about systematic affinities between two species of Chironius (Serpentes, Colubridae). Phyllomedusa, 2 (1), 65–67.

    McDonald, J.H. (2009) Handbook of Biological Statistics. Sparky House Publishing, Baltimore, Maryland, 313 pp.

    Müller, P. (1969) Zur Verbreitung der Gattung Chironius auf den südbrasilianischen Inseln (Serpentes, Colubridae). Senckenbergiana Biologica, 50 (3/4), 133–141.

    Nascimento, L.P., Siqueira, D.M. & Santos-Costa, M.C. (2013) Diet, reprodution, and sexual dimorphism in the Vine snake, Chironius fuscus (Serpentes: Colubridae), from Brazilian Amazonia. South American Journal of Herpetology, 8 (3), 168–174.

    Paynter Jr., R.A. & Traylor Jr., M.A. (1991) Ornithological Gazetteer of Brazil. Vols. 1 & 2. Bird Department, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, viii + 789 pp., 2 maps.

    Peters, J.A. & Orejas-Miranda, B. (1970) Catalogue of the Neotropical Squamata. Part I. Snakes. United States National Museum Bulletin, 297, 1–347.

    QGIS Development Team (2016) QGIS Geographic Information System. Open Source Geospatial Foundation Project. Available from: (accessed 13 July 2017)

    Sabaj, M.H. (2016) Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an online reference. Version 6.5 (16 August 2016). American Society of Ichthyologists and Herpetologists, Washington, DC. Available from: (accessed 8 June 2017)

    Savitzky, A.H., Mori, A., Hutchinson, D.A., Saporito, R.A., Burghardt, G.M., Lillywhite, H.B. & Meinwald, J. (2012) Sequestered defensive toxins in tetrapod vertebrates: principles, patterns, and prospects for future studies. Chemoecology, 22, 141–158.

    Shreve, B. (1959) A new Phyllomedusa from Bolivia (Salientia, Hylidae). Breviora, 113, 1–4.

    Sokal, R.R. & Rohlf, F.J. (1995) Biometry: The Principles and Practice of Statistics in Biological Research. W.H. Freeman Company, New York, 880 pp.

    SPSS Inc. (2008) SPSS Statistics for Windows 17.0. Chicago, Illinois.

    Uetz, P. & Hosek, J. (2016) The Reptile Database. Available from: (accessed 28 June 2016)

    Vanzolini, P.E. (1977) An annotated bibliography of the land and fresh-water reptiles of South America (1758–1975). Vol. I (1758–1900). Museu de Zoologia, Universidade de São Paulo, São Paulo, 186 pp.

    Vanzolini, P.E. (2004) Episódios da Zoologia Brasílica. Hucitec, São Paulo, 212 pp.

    Vanzolini, P.E. & Myers C.W. (2015) The herpetological collection of Maximilian, Prince of Wied (1782-1867), with special reference to Brazilian materials. Bulletin of the American Museum of Natural History, 395, 1–155.

    Wagler, J. (1824) Serpentum brasiliensium species novae ou Histoire naturelle des espèces nouvelles de serpens, recueillies et observées pendant le voyage dans l'intérieur du Brésil dans les années 1817, 1818, 1819, 1820, exécuté par ordre de Sa Majesté le Roi de Bavière, publiée par Jean de Spix, ... décrite d' après les notes du voyageur par Jean Wagler. Franc. Seraph. Hübschmann, Monachii, viii + 26 pls. + 75 pp.

    Wallach, V., Williams K.L. & Boundy, J. (2014) Snakes of the World: A Catalogue of Living and Extinct Species. CRC Press/Taylor and Francis, Boca Raton, Florida, xxvii + 1209 pp.

    Warrell, D.A., Theakston, R.D.G. & Wüster, W. (2010) Destruction of the collection of reptiles and arthropods at Butantan Institute: a view from the United Kingdom. The Journal of Venomous Animals and Toxins including Tropical Diseases, 16, 534–536.

    Wied, Maximilian Prinz zu. (1820) Reise nach Brasilien in den Jahren 1815 bis 1817. Vol. 1. H.L. Brönner, Frankfurt a.M., xxxiv + 385 pp.

    Wied, Maximilian Prinz zu. (1824) Verzeichnis der Amphibien, welche im zweiten Bande der Naturgeschichte Brasiliens vom Prinz Max von Neuwied warden beschrieben werden. Isis von Oken, 14, 666. [column]

    Wied, Maximilian Prinz zu. (1825a) Abbildungen zur Naturgeschichte Brasiliens (Recueil de planches coloriées d'Animaux du Brésil). im Verlage des Grossherzogl. Sächs. priv. Landes-Industrie-Comptoirs, Weimar, 9 Lief., pl. 3. [for contents see Isis von Oken, 17, 922]

    Wied, Maximilian Prinz zu (1825b) Beiträge zur Naturgeschichte von Brasilien. Vol. 1. Gr. H. S. priv. Landes-Industrie-Comptoirs, Weimar, xxii + 614 pp., 1 pl.

    Williams, B.L., Brodie, E.D. Jr. & Brodie, E.D. III (2004) A resistant predator and its toxic prey: persistence of newt toxin leads to poisonous (not venomous) snakes. Journal of Chemical Ecology, 30, 1901–1919.

    Zaher, H., Grazziotin F.G., Cadle, J.E., Murphy, R.W., Moura-Leite, J.C. & Bonatto, S.L. (2009) Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with emphasis on South American Xenodontines: a revised classification and descriptions of new taxa. Papéis Avulsos de Zoologia, 49 (11), 115–153.

    Zar, J.H. (1999) Biostatistical Analysis. 4th Edition. Prentice Hall, Upper Saddle River, New Jersey, 663 pp.