New records and distribution extensions of three species of Mesoclemmys Gray , 1863 ( Testudines : Chelidae ) in Mato Grosso state , Brazil , with observations on terrestrial movements Mesoclemmys

Distribution patterns of most of the 20 Neotropical freshwater turtles belonging to the family Chelidae are usually based on few locality records. We here report on vouchered records of three species of the chelid genus Mesoclemmys in the Brazilian state of Mato Grosso. Presence of M. vanderhaegei is confirmed for the Amazon River Basin, and M. gibba and M. raniceps are recorded in Mato Grosso for the first time.

Although studies on Neotropical freshwater turtles have increased during the last years, several species are still poorly known, especially in regard to distributional records that are limited to a few localities.Among these are most of Brazilian freshwater turtles of the family Chelidae (Souza 2004;2005).It presently comprises 20 species, eight of which belong to the genus Mesoclemmys (Bérnils and Costa 2011).Up to now, only one species in this genus (M.vanderhaegei) is positively recorded for the Brazilian state of Mato Grosso, which encompasses the headwaters of two major South American river basins: Amazon and Plata.We here present new locality records and range extensions for three species of Mesoclemmys (Figure 1) in Mato Grosso.We also call attention to the ability of these turtles to occasionally migrate across land, between aquatic habitats or even between distinct watersheds.
Previous records of the Vanderhaege's toad-headed turtle Mesoclemmys vanderhaegei (Bour, 1973) in Brazil refer mainly to localities belonging to the Parana-Paraguay River sub-basins of the Plata River Basin (e.g., Iverson 1992;Souza et al. 2000;Strüssmann 2000;Strüssmann et al. 2000;Brandão et al. 2002;Bour and Zaher 2005).Besides Mato Grosso, known records of M. vanderhaegei include the states of Mato Grosso do Sul and São Paulo.The species was also recorded in the São Francisco River Basin, in Minas Gerais State (Silveira 2009), and in streams of the southeastern portion of the Amazon River Basin (Araguaia-Tocantins sub-basin), in the states of Tocantins and Goiás (Brandão et al. 2002;Villaça 2004).Nevertheless, these Amazonian records were not considered by Bour and Zaher (2005), who revised the distribution of the genus Abstract: Distribution patterns of most of the 20 Neotropical freshwater turtles belonging to the family Chelidae are usually based on few locality records.We here report on vouchered records of three species of the chelid genus Mesoclemmys in the Brazilian state of Mato Grosso.Presence of M. vanderhaegei is confirmed for the Amazon River Basin, and M. gibba and M. raniceps are recorded in Mato Grosso for the first time.
New records and distribution extensions of three species of Mesoclemmys Gray, 1863 (Testudines: Chelidae) in Mato Grosso state, Brazil, with observations on terrestrial movements Mesoclemmys.
Species identifications followed keys and diagnoses in Ernst and Barbour (1989), Pritchard and Trebbau (1984) and Rueda-Almonacid et al. (2007).As a tool for identification, we also provide (Table 1) measurements of carapace length (CL), head width (HW), and ratio between HW and CL, for some of the specimens of Mesoclemmys referred herein.Vouchers are deposited in the Coleção Zoológica de Vertebrados of the Universidade Federal de Mato Grosso (UFMT, Cuiabá, Mato Grosso, Brazil).
We here report seven records of the presence of M. vanderhaegei in Mato Grosso rivers belonging to three distinct Amazonian sub-basins (Guaporé-Madeira, Juruena-Tapajós, and Araguaia-Tocantins) of the southern section of the Amazon River Basin (Figure 2).In the municipality Vale de São Domingos, southwestern Mato Grosso, an adult individual of M. vanderhaegei (UFMT 1625) was captured on 30/May/2002.It was crossing an unpaved road near the Guaporé River hydroelectric powerplant (UHE Guaporé; 15°07' S, 58°57' W).In the municipality Vila Bela da Santíssima Trindade, two specimens (a juvenile, UFMT 8423, and two adults, UFMT 8767; UFMT 8768) were captured on 14/March/2008, in a small stream impoundment of a gold mining project (Projeto São Francisco) in the top of Serra da Borda (14°51' S, 59°39' W).In the same locality and habitat, another juvenile (UFMT 8565) was collected on 17/April/2010.River courses from Vale de São Domingos and from Vila Bela da Santíssima Trindade both belong to the Upper Guaporé River Basin.Guaporé River is an affluent of the Madeira River, a major contributor of the right margin of the Amazon River.In the municipality Juína, an adult of M. vanderhaegei (UFMT 6056) was captured on 04/December/2006, while crossing an unpaved road near the Juruena River (11°20' S, 59°07' W).This is a main affluent of the Tapajós River, also a major contributor of the right margin of the Amazon River.
In the municipality Nova Xavantina, an adult female (UFMT 8764) was captured on 16/April/2003, in a pitfall trap amidst a sandy area covered by open vegetation ("cerrado sentido restrito", sensu Ribeiro and Walter, 1998).The pitfall was installed near the margins of the small and olygotrophic Bacaba stream (14°43' S, 52°21' W).Bacaba is an affluent of the Mortes River, which belongs to the Araguaia-Tocantins sub-basin.To our knowledge, this is the southernmost record of that species in this sub-basin.
Presence of M. vanderhaegei was also recorded in both natural and urban areas of two municipalities in southern Mato Grosso (Figure 2), amidst Cerrado (Brazilian's second largest ecosystem, covering most of Central Brazil).On 23/ December/2004, during the local dry season, a juvenile of M. vanderhaegei (not collected) was found crossing a sandy, unpaved road inside the National Park of Chapada dos Guimarães, mostly situated in the municipality Chapada dos Guimarães.Also in December/2004, a juvenile specimen (UFMT 1787) was found road killed on a paved street of the urban area of Cuiabá, the capital of Mato Grosso State.On 20/April/2010, in the same municipality, an adult female (UFMT 8564) was found at an urban site still covered by "cerrado sentido restrito" vegetation.
Two additional species of the genus Mesoclemmys are herein reported to be present in the state of Mato Grosso (Figure 2): Mesoclemmys gibba (Schweigger, 1812) and Mesoclemmys raniceps (Gray, 1855).The first species is widely distributed in the Orinoco River and the Amazon River basins, in Guyana, Suriname, French Guiana, Colombia, Ecuador, Peru, Venezuela, Trinidad, and northern Bolivia and Brazil (Bour and Zaher 2005 and references therein;Rueda-Almonacid et al. 2007;Vogt 2008;Ferronato et al. 2010).
Little is known on the distribution of M. gibba in Brazil.Confirmed records in Brazil are limited to the states of Amazonas (Schneider et al. 2009), Pará (Mittermeier et al. 1978;Avila-Pires et al. 2010), Acre (Bernarde et al. 2011), and Tocantins (Pavan and Dixo 2004).Therefore, the species seems to be restricted to the Amazon basin, as also inferred from distribution maps provided by Iverson (1992), Bour andZaher (2005), andRueda-Almonacid et al. (2007), among others.We are unaware of any previous confirming record of its presence in Mato Grosso State (but see São Pedro et al. 2009).
Another representative of the genus Mesoclemmys here shown to be present in northwestern Mato Grosso State is M. raniceps.As M. gibba, it is widely distributed in the Orinoco River and Amazonas River basins, being known from Colombia, Venezuela, Peru, Bolivia, and Brazil (Iverson 1992;McCord et al. 2001;Bour and Zaher 2005).In Brazil, it was until now restricted to the states of Acre, Rondônia, Amazonas, and Para, as suggested by general distribution maps, as those provided by Iverson (1992), McCord et al. (2001), Bour and Zaher (2005) of Mesoclemmys vanderhaegei, for example, may be a result of the ability of these turtles to perform terrestrial displacements between water bodies (sometimes crossing interfluves), especially at the end of the rainy season.Indeed, individuals of M. vanderhaegei were found in dry places in nearly half of the records reported herein.
Reasons to do so probably include the search for empty territories or for suitable places to spend the dry season, among others.Terrestrial displacements were already reported for other freshwater turtles, such as the chelid Chelodina longicollis (Roe and Georges 2008;Rees et al. 2009), and the emydids Trachemys scripta (Gibbons et al. 1990), Emydoidea blandingii (Ross and Anderson 1990), and Clemmys guttata (Haxton and Berrill 2001).Presumably, most freshwater turtles have the skill to migrate across land, and effectively do it when resources become meager in their original aquatic habitats (Kramer 1995;Milan and Melvin 2001).Due to this ability, and also considering the confluence of at least three distinct ecosystems and river basins in the state of Mato Grosso, representatives of Chelidae probably have even wider ranges than presently indicated by available data.

Table 1 .
Mesoclemmys spp.are frequently found while crossing dry habitats or interfluves.The wide distribution Carapace length (CL) and head width (HW), in mm, and ratio between HW and CL in selected specimens of Mesoclemmys from Mato Grosso State, Brazil.U -unsexed; F -female; M -male.