Abstract

RIOJA-PARADELA, Tamara; CARRILLO-REYES, Arturo; CASTANEDA, Gamaliel  and  LOPEZ, Sergio. Herpetofaunal diversity north of lower lagoon, Tehuantepec Isthmus, Oaxaca, Mexico. Acta Zool. Mex [online]. 2013, vol.29, n.3, pp.574-595. ISSN 2448-8445.

This study was developed in order to determine the annual and seasonal herpetofauna diversity of Montecillo Santa Cruz, Municipality of San Francisco del Mar, Oaxaca, at the south of the Isthmus of Tehuantepec. Between November 2010 and November 2011, over 48 field work days (24-dry season and 24-wet season), two 500 m long and 10 m wide transects were established in open grassland, nanchal, tropical deciduous forest and riparian vegetation. We recorded in an area of 20 km², a total of 49 species (10 species of amphibians and 39 species of reptiles). This richness represents 30.61% of the total herpetofauna of Oaxaca. A total of 46 species were recorded at the wet season (10 amphibians and 37 reptiles) and 37 at the dry season (4 amphibians and 33 reptiles). The 30.61% of the total are listed in some risk category in the NOM-059-SEMARNAT-2010, one species is listed as critically endangered (Ctenosaura oaxacana) by the IUCN Red List, and four more are in the Appendix II of CITES. Throughout the study, the tropical deciduous forest presented the highest alpha diversity (H' = 3.2900, 1 / D = 20.6), while the open grassland was the one with less diversity (H' = 3.1664, 1 / D = 17.14). On a seasonal basis, the deciduous forest showed the highest diversity (H' = 3.2900, 1 / D = 20.6 wet season, H' = 3.0850, 1 / D = 17.71 dry season), while the lowest diversity was recorded in the riparian vegetation during the wet season (H' = 3.1009, 1 / D = 16.61), and in the grassland (H'= 2.7095, 1 / D = 11.40) during the dry season. Throughout the study, the vegetation associations that shared a greater number of species were tropical deciduous forest and riparian vegetation (P = 0.7045 and S = 0.5613), coinciding with the seasonal results (J = 0.6500 and S = 0.4921 wet season, J = 0.6333 and S = 0.4489 dry season). We found a high diversity in a relatively small area, so the area can be considered as important for the distribution of amphibians and reptiles, and therefore is essential to establish conservation and management measures for these species and their habitats.

Keywords : amphibians; conservation; diversity; inventory; reptiles.