Herpetofauna, Ponte de Pedra Hydroelectric Power Plant, states of Mato Grosso and Mato Grosso do Sul, Brazil

This paper presents a check list of amphibians and reptiles of the area under influence of Ponte de Pedra hydroelectric power plant on Correntes River (municipality of Sonora), between the Brazilian states of Mato Grosso do Sul and Mato Grosso. The list was the result of collecting efforts of a Faunal Program (inventory, rescue, and monitoring) carried out between November 2003 and April 2005. The list comprises 2 orders (Gymnophiona and Anura), 7 families (Caeciliidae, Bufonidae, Cycloramphidae, Hylidae, Leiuperidae, and Leptodactylidae) 14 genera, and 33 species of amphibians and 3 orders (Testudines, Crocodylia, and Squamata), 20 families (Chelidae, Testudinidae, Alligatoridae, Amphisbaenidae, Anguidae, Gekkonidae, Phyllodactylidae, Gymnophtalmidae, Hoplocercidae, Polychrotidae, Scincidae, Teiidae, Tropiduridae, Anomalepididae, Leptotyphlopidae, Typhlopidae, Boidae, Colubridae, Elapidae, and Viperidae), 51 genera, and 72 species of reptiles.


Introduction
The knowledge of vertebrate species composition of a given area is an important factor in conservation projects.
Accordingly, the identification of amphibians and reptiles and the study of their ecological characteristics are decisive for the success of actions directed to biodiversity conservation (Heyer et al. 1994).A considerable amount of data related to richness and composition of communities may be assembled through appropriate bibliography and field inventories.Herpetological inventories can offer a wider vision of distributional patterns of a large number of species which optimizes the comprehension efforts of species distribution related to different environmental variables.

Nowadays
the vegetation physiognomies originally found in the Brazilian states of Mato Grosso and Mato Grosso do Sul have suffered intense transformation due to anthropic actions, especially agriculture and pasture (cattle ranching).These environmental modifications implicated in a process of landscape degradation and fragmentation that resulted in the reduction of population sizes, with possible local extinctions (Primack 2002).The states of Mato Grosso and Mato Grosso do Sul possess areas with typical phytophysiognomies of Pantanal, Cerrado, and Chaco (Prado and Gibbs 1993;Spichiger et al. 2004;Morrone et al. 2004) (Bucher 1980;Vanzolini 1988;Cabrera 1995;Duellman 1999;Colli et al. 2002;Souza 2005).Despite the biological and biogeographical relevance this diagonal area has received little attention in studies of regional scope.
This study presents herpetological information of the Cerrado-Pantanal ecotones in the limits of the South American open areas between Mato Grosso do Sul and Mato Grosso states.The species list is based on specimens collected during the Program of Faunal Monitoring and Rescue of the Ponte de Pedra hydroelectric power plant located in the municipality of Itiquira, state of Mato Grosso.

Materials and Methods
The Ponte de Pedra hydroelectric power plant (UHE Ponte de Pedra) is located on Correntes River, municipality of Itiquira, between Mato Grosso and Mato Grosso do Sul states (17°36'31" S and 54°49'40" W), with an estimated reservoir of 14.5 km 2 (Figure 1).The study area is in a shallow valley of granitic rocks with a vegetational mosaic of gallery forests, dense Cerrado, open Cerrado, with an important presence of veredas (swampy areas with unique vascular vegetation).On most of the surrounding areas the environment is fragmented with agriculture practices (mostly sugar cane and soy bean), with the best preserved areas located adjacent to the power plant dam (downriver).During the filling of the reservoir (1 April to 18 September 2004) we used three 6 meter aluminum boats equipped with 40 HP outboard engines with a crew of 1 biologist, 1 assistant, and 1 pilot each.All vegetated areas and land were searched every day, at least 4 times a day, including the reservoir margins.Animals were collected using herpetological hooks, nets, laces, and forceps, and then transferred to plastic vials (several sizes), plastic bags, and cloth bags until their final destination in the biological laboratory at the rescue base.The animals were then separated, identified and registered as to margin and location of collecting in the reservoir.
All collecting activities were legally permitted accordingly to IBAMA 02001.005547/99-49process and permits IBAMA 0150/2003 and 065/2004-CGFAU/LIC.All collected specimens were deposited at the herpetological collection of the Museu de Zoologia of the Universidade de São Paulo (MZUSP).
The reptiles were represented by 72 species from 51 genera, and 20 families of the orders Chelonia, Crocodylia, and Squamata.The order Squamata was the most representative, with 95.8 % (N=69) of the reptiles, followed by Chelonia with 2.8 % (N=2), and Crocodylia with 1.4 % (N=1).Amphisbaenians, lizards, and snakes (Squamata) are the categories with higher taxonomic diversity among reptiles.These forms occupy a great variety of habitats and during the filling of the reservoir they are represented with a very expressive number of individuals.Among Squamata the suborders were represented as follows: Amphisbaenia -1 family, 3 genera and 8 species; Sauria -9 families, 17 genera and 23 species; and Serpentes -7 families, 28 genera and 39 species (Appendix 1).
Most of amphibian species is associated to open habitats (especially wetlands) and are generalists.The only species found exclusively in forested habitats was Osteocephalus taurinus (Figure 2).Dendropsophus tritaeniatus is listed as endemic to Cerrado (Strüssmann 2000) with a suggested restricted distribution to SE Mato Grosso (Frost 2008).The species Leptodactylus gracilis and Physalaemus bilingonigerus are typical of Pantanal (Figure 2).These data are suggestive of the ecotone Cerrado-Pantanal.
The Cerrado reptile species are in most cases poorly represented in herpetological collections making it difficult to produce reliable distributional ranges.Several collected species (Anolis meridionalis, Bachia bresslaui, Coleodactylus brachystoma, and Hoplocercus spinosus -Figure 2) are related to this ecosystem (Colli et al. 2002).The remaining species present different distributional patterns: Mabuya bistriata and Tupinambis quadrilineatus in the Amazon realm (Ávila-Pires 1995); Tropidurus guarani, Mabuya guaporicola, Liophis frenatus, Lygophis meridionalis, and Philodryas mattogrossensis are common in Cerrado and Chaco (Cei 1993, Ávila-Pires 1995, Strüssmann 2000); Cercosaura schreibersii and Mabuya dorsivittata in Cerrado, Chaco and Pampas (Ávila-Pires 1995); Mabuya frenata, Tropidurus torquatus and Sibynomorphus mikanii (Figure 2) in Cerrado and Atlantic Forest; Amphisbaena pretrei e Micrablepharus maximiliani in Cerrado and Caatinga (Rodrigues 1996;Gans 1965); Tupinambis merianae and Crotalus durissus (Figure 2) in all formations south of the Amazon (Ávila-Pires 1995); Ameiva ameiva in all of South America (Vitt and Colli 1994); and the cosmopolitan Hemidactylus mabouia.However, the majority of species occur in the South American open areas diagonal (Caatinga-Cerrado-Chaco).Despite the results presented here there are several taxa that might represent range extensions or new forms yet to be described owing to complex taxonomic group.----------------Appendix 1. Amphibians and reptiles recorded in the region affected by Ponte de Pedra hydroelectric power plant (municipality of Sonora, state of Mato Grosso do Sul, Brazil).Habits according to Strüssmann (2000): AB = arboreal species (species rarely seen on the ground); SAB = sub arboreal species (species inhabiting all vegetational levels and very often seen on the ground; CR = cryptozoic species (species that use habitats under rocks, fallen logs, or soil debris); TE = terrestrial (species that use habitats on the ground and occasionally on lower vegetational strata); FO = fossorial (species inhabiting higher soil strata); SFO = semi fossorial (species inhabiting higher soil strata but feed on the surface); SAQ = semi aquatic (species that feed primarily on the water but also use terrestrial habitats); PA = paludicola (species associated to lagoons and swampy areas = wetlands).

Figure 1 .
Figure 1.Location of UHE Ponte de Pedra on the border of Mato Grosso do Sul (MS) and Mato Grosso (MT) states -----------Field activities during the faunal inventory were carried out between 11 November 2003 and 10 January 2004, and the post filling faunal monitoring between 18 September 2004 and 10 April 2005.For monitoring we used pit-falls with 18L and 100L plastic buckets distributed in 20 collecting stations in 9 straight lines to a total of 180 traps per collecting station.Distance between buckets was 3 meters, and 4 meters between lines.Each collecting station was composed of 25 buckets of 100L and 155 buckets of 18L in an sampling area of 1,824m 2 .We used 4 collecting stations (totaling 720 numbered pit-falls) in different phytophysiognomies (open cerrado, dense cerrado, gallery forest).Traps were visited 4 times (at 8:00, 11:00, 14:00, and 17:00 hours) daily.Animals were transferred to plastic bags or vials with all pertinent collecting data (date, time, and number of pitfall trap).