First record of the genus Chiasmocleis Mèhelÿ , 1904 ( Anura , Microhylidae ) in Argentina

Chiasmocleis Mèhelÿ, 1904 is the most diverse genus of Microhylidae, with 25 described species distributed from Panamá to Asunción in Paraguay. Chiasmocleis albopunctata (Boettger, 1885) is the most widely distributed species of the genus (Peloso et al. 2014), being present 06°00′ S in State of Tocantins, Brazil, to 25°18′ S in Asunción, Paraguay. It inhabits open vegetation areas like those of Cerrado, Chaco and the transitional areas between them, as well as transitional areas between Cerrado and Amazonian and Atlantic Forests (Peloso et al. 2014). Chiasmocleis albopunctata is characterized by its elongated body; short and rounded snout; fingers and toes lacking interdigital webbing and adhesive discs, and having a slight fringe and scarce, small dermal spines; absence of occipital fold; presence of a postorbital fold; scattered dermal spines in dorsum; coloration characterized by dark gray dorsum with a whitish bar on snout, extending along canthus rostralis, superior eyelid, and fragmented in irregular blotches on shoulders; scattered, irregularly distributed whitish blotches on dorsum, arms, legs; venter gray with large, well delimited, and irregularly distributed whitish blotches (Caramaschi and Cruz 1997) (Figure 1). We recorded 29 individuals of C. albopunctata using pitfall traps with drift-fences (Figure 2) from December 2013 to February 2014 in La Ascensión ranch, La Picadita, Municipality of Colonia Villafañe, Departmento Pirané, Province of Formosa, Argentina (26°02′16′′ S, 59°09′26′′ W) (Figure 3). The area corresponds to a Chaco subregion known as Humid Chaco (Chaco Húmedo) (Secretaría de Desarrollo Sustentable y Política Ambiental and Ministerio de Desarrollo Social y Medio Ambiente 1999). Vegetation in the area is a mosaic of Chaco forests intermingled with seasonally flooded areas called “bañados” and “esteros”. The specimens were identified based in the diagnostic characters provided by Caramaschi and Cruz (1997), and measured (SVL) using a digital caliper (precision of 0.01 mm). We used the minimum SVL of males (23.2 mm) and females (28.2 mm) and the presence of dark vocal sac as a diagnostic character to identify males, females and Abstract: Chiasmocleis Mèhelÿ, 1904 is the most diverse genus of Microhylidae, with Chiasmocleis albopunctata (Boettger, 1885) being the species with the largest distribution. This species is typical of open habitats from State of Tocantins in Brazil to Asunción in Paraguay, which is its southernmost previous record. Herein we report the first record of C. albopunctata in Argentina, extending its known distribution 173 km SW from Asunción in Paraguay. Laboratorio de Ecología y Conservación de la Herpetofauna, Instituto de Diversidad y Ecología Animal, (IDEA, CONICET-UNC) and Centro de Zoología Aplicada (UNC). Rondeau 798 X5000AVP Córdoba, Argentina. * Corresponding author. E-mail: nicolas.pelegrin@conicet.gov.ar José Manuel Sánchez, Giuliano Paolo Pesci, Suelem Muniz Leão and Nicolás Pelegrin* First record of the genus Chiasmocleis Mèhelÿ, 1904 (Anura, Microhylidae) in Argentina

Chiasmocleis Mèhelÿ, 1904 is the most diverse genus of Microhylidae, with 25 described species distributed from Panamá to Asunción in Paraguay.Chiasmocleis albopunctata (Boettger, 1885) is the most widely distributed species of the genus (Peloso et al. 2014), being present 06°00′ S in State of Tocantins, Brazil, to 25°18′ S in Asunción, Paraguay.It inhabits open vegetation areas like those of Cerrado, Chaco and the transitional areas between them, as well as transitional areas between Cerrado and Amazonian and Atlantic Forests (Peloso et al. 2014).
Chiasmocleis albopunctata is characterized by its elongated body; short and rounded snout; fingers and toes lacking interdigital webbing and adhesive discs, and having a slight fringe and scarce, small dermal spines; absence of occipital fold; presence of a postorbital fold; scattered dermal spines in dorsum; coloration characterized by dark gray dorsum with a whitish bar on snout, extending along canthus rostralis, superior eyelid, and fragmented in irregular blotches on shoulders; scattered, irregularly distributed whitish blotches on dorsum, arms, legs; venter gray with large, well delimited, and irregularly distributed whitish blotches (Caramaschi and Cruz 1997) (Figure 1).
We recorded 29 individuals of C. albopunctata using pitfall traps with drift-fences (Figure 2) from December 2013 to February 2014 in La Ascensión ranch, La Picadita, Municipality of Colonia Villafañe, Departmento Pirané, Province of Formosa, Argentina (26°02′16″ S, 59°09′26″ W) (Figure 3).The area corresponds to a Chaco subregion known as Humid Chaco (Chaco Húmedo) (Secretaría de Desarrollo Sustentable y Política Ambiental and Ministerio de Desarrollo Social y Medio Ambiente 1999).Vegetation in the area is a mosaic of Chaco forests intermingled with seasonally flooded areas called "bañados" and "esteros".The specimens were identified based in the diagnostic characters provided by Caramaschi and Cruz (1997), and measured (SVL) using a digital caliper (precision of 0.01 mm).We used the minimum SVL of males (23.2 mm) and females (28.2 mm) and the presence of dark vocal sac as a diagnostic character to identify males, females and   Acknowledgments: We thank Dirección de Recursos Naturales y Gestión of Secretaría de Ambiente de la Provincia de Formosa for collection permits.The Rufford Foundation funded part of the study through the Rufford Small Grant 13880-1 "Contributions from science and social awareness to the conservation of Chaco reptiles in Argentina".MINCyT (Argentina) and CAPES (Brazil) founded part of this study through the International Cooperation Project MINCyT-CAPES BR/11/ RED/08 "Orígenes, biogeografía y conservación de la herpetofauna de la diagonal abierta sudamericana".We also thank Guarino R. Colli, Davi L. Pantoja and local people for their assistance during fieldwork.
Figure 2. A: Picture of one of the drift-fence pitfall trap arrays used in the present study located in an open area within the Humid Chaco forest; B: General view of the interior of the sampled Humid Chaco Forest.Note the dominant cover of bromeliads of the ground.

Figure 3 .
Figure 3. Map showing the localization of the new records in La Picadita, Colonia Villafañe, Formosa, Argentina, and the three nearest records in Paraguay.Brazilian records were not included.