Although Tropidurus is a widely distributed lizard genus in South America and the Galapagos Islands, studies on space use and spatial distribution are scarce. We studied the home range structure of the saxicolous lizard Tropidurus torquatus based on the inland population of a rock outcrop in Minas Gerais State, southeastern Brazil. Lizards were individually marked and observed during reproductive and non-reproductive seasons. Using the minimum convex polygon method, we found that average total range size of males during the reproductive season was larger than that of females, and that both had similar total range sizes in the nonreproductive season. The harmonic mean method showed that males have a larger home range size than that of females during both seasons. As expected for a polygynous species, the average number of males whose total ranges overlapped those of females tended to be higher in the reproductive season than in the nonreproductive season. Intrasexually, the number of females whose total ranges were associated with those of other females was also higher in the reproductive season than in the non-reproductive season. For males, this number remained low in both seasons, suggesting that males use more exclusive areas, whereas the smaller total ranges of females apparently sustain a higher density of individuals during the reproductive season. Frequency of microhabitat use in relation to vegetation increased in the non-reproductive season and the activity patterns of lizards shifted from bimodal in the reproductive season (rainy period) to unimodal in the non-reproductive season (dry period). Thus, the range structure, microhabitat use, and activity patterns of the T. torquatus observed here were all influenced by the time frame affecting their spatial ecology.

The aim of the present study was to investigate the relationship between nematode infection and the ontogeny and diet of the lizard Tropidurus torquatus from a rocky outcrop in the state of Minas Gerais, south-eastern Brazil. Eighty-nine of 110 lizards examined (81.9%) harboured nematodes. Two nematode species were identified, namely, Physaloptera lutzi in the stomach and Parapharyngodon bainae in the intestine, with prevalence values of 67.3 and 60.0%, respectively. The lizard diet was composed mainly of ants, other hymenopterans, beetles and flowers of the species Centrosema coriaceum (Fabaceae). Host body size was positively correlated with nematode abundance, with adults more heavily parasitized than juveniles. The consumption of C. coriaceum had a negative effect on the abundance of both nematode species, suggesting that this plant may possess anthelmintic properties. The probability of a higher worm burden in adult hosts is likely linked with a longer exposure time to infective stages. Beetles, ants and hymenopterans appear to be the main intermediate hosts for P. lutzi. In general, ontogeny and diet composition determine the structure of the helminth community in this species of lizard.

Data on reptile fauna in the state of Minas Gerais are punctual and show the need of information about this group, mainly in transition regions between the Atlantic Forest and the Cerrado. The study area is located in Ritápolis municipality (21° 01' 37.07" S and 44° 19' 11.84" W), micro-region Campo das Vertentes, State of Minas Gerais, Southeastern Brazil. The aim of this study was to study the composition of the local reptile fauna. The observations, captures and collections were performed every two weeks, during two consecutive days, from August 2005 to July 2006. The captures were made using pitfall traps with drift fences, divided in eight sites: four in the gallery forest area and four in open areas, totalizing 6.912 hours-bucket of sampling effort. We also performed active captures, used photographs to register occasional encounters and in some cases we also obtained snake specimens that were delivered by local people when found dead. We recorded a total of 31 reptile species, two turtle species; nine lizards; two amphisbaenians and 18 snakes. Only the lizards Cercosaura ocellata, Enyalius bilineatus and Tupinambis merianae and the snakes Leptodeira annulata and Apostolepis assimilis were captured by pitfall traps. The most common lizards were Ameiva ameiva and Mabuya frenata and the most abundant snakes were Oxyrhophus guibei and Sibynomorphus mikanii. Lizards are very well represented in the area, with species typical of the forest, as Enyalius bilineatus, and from Cerrado open areas, as Ameiva ameiva and Mabuya frenata. The snake assemblage contains species typical of Cerrado open areas (e. g. O. guibei and Micrurus frontalis), and of forests, as Liophis poecilogyrus and Philodryas olfersii. The diversity of reptile species and the previous record of Amphisbaena dubia and Hydromedusa tectifera in the state of Minas Gerais indicate the great potential of the Campo das Vertentes to reveal the occurrence of new species or to extend the distribution of other species.

Abstract:The Atlantic Forest of the state of Minas Gerais, as well as the remnants of this domain in the rest of Brazil, suffers a marked reduction in size and anthropogenic alteration. This habitat degradation is directly reflected in the decrease of species richness within these natural environments. In this sense, the inventory of extant species is necessary to understand the species composition of regions under threat. Despite the great richness of existing reptile species in Minas Gerais, the level of knowledge about the fauna in this state is considered unsatisfactory and very fragmented. The aim of this study was to record the composition of the reptile fauna of the municipality of Juiz de Fora through the revision of specimens housed at the Herpetological Collection of the Federal University of Juiz de Fora (CHUFJF-Reptiles) and published papers. Better documentation of the reptilian fauna for the region not only expands the knowledge of the herpetofauna of Minas Gerais, but also contributes to regional conservation planning, such as "Biota Minas" program in the states of the Minas Gerais, Brazil. A total of 41 reptile species (two freshwater turtles, two amphisbaenians, 13 lizards and 24 snakes) belonging to 12 families were recorded. We highlight the record of the freshwater turtle Hydromedusa maximiliani, which is considered a species sensitive to anthropogenic impact and currently is seen only in protected areas in Juiz de Fora, as well as Ecpleopus gaudichaudii, Enyalius brasiliensis, Heterodactylus imbricatus, Placosoma glabellum and Micrurus corallinus, that are dependent on well-preserved forest areas. The reptile composition is more similar to Viçosa and other surrounding regions, despite the presence of many species that are not shared between these locations. This fact demonstrates the importance of the collection in terms of representativeness of the local and regional fauna as well as providing a valuable source of information for future studies of Brazilian herpetofauna in general.

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original RESUMO Este estudo teve como objetivo avaliar o efeito do número de animais por gaiola sobre o comportamento de ansiedade em camundongos expostos ao labirinto em cruz elevado. Trinta camundongos foram divididos em dois grupos: grupo 1 (G1) e 2 (G2) com 10 e 20 animais, respectivamente, em cada gaiola. Ao atingir 90 dias de idade, cada animal foi submetido ao labirinto em cruz elevado, apenas uma vez no período de 5 minutos. Os parâmetros avaliados em ambos os grupos foram: porcentagem do número de entradas nos braços abertos (% NBA) e a porcentagem de tempo gasto nos braços abertos (% TBA). A análise estatística não detectou diferenças significativas entre os dois grupos na % NBA (p = 0,87), nem com relação à % TBA (p = 0,98). O trabalho concluiu que a manutenção de 10 ou 20 animais por gaiola não causou nenhuma alteração significativa nos níveis de ansiedade dos mesmos, o que sugere ser indiferente manter 10 ou 20 camundongos por gaiola. ABSTRACTThis study aimed to evaluate the effect of the number of animals per cage behaviour of anxiety in mice exposed to elevated plus-maze. Thirty Swiss mice were divided into 2 groups: group 1 (G1) and group 2 (G2) with 10 and 20 animals respectively in each cage. Upon reaching 90 days of age, each animal was submitted to the elevated plus-maze, only once in the period of 5 minutes. The parameters evaluated in both groups were: percentage of the number of entries in open arm (% nBA) and percentage of time spent in open arms (% tBA). The statistical analyis did not yield significant difference between the two groups in regarding %nBA (p = 0.87) nor with respect to tBA% (p = 0.98). Our work concluded that the maintenance of 10 or 20 mice per cage did not cause any significant alteration in the anxiety levels of the animals, thus it suggests being indifferent to maintain 10 or 20 mice per cage.

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