Alexandre F. B. de Araújo

Phylogeny and Ecology Determine Morphological Structure in a Snake Assemblage in the Central Brazilian Cerrado

Abstract To investigate the role of ecological and historical factors in the organization of communities, we describe the ecomorphological structure of an assemblage of snakes (61 species in six families) in the Cerrado (a savanna-like grassland) of Distrito Federal, Brazil. These snakes vary in habits, with some being fossorial, cryptozoic, terrestrial, semi-aquatic, or arboreal. Periods of activity also vary. A multivariate analysis identified distinct morphological groups associated with patterns of resource use. We report higher niche diversification compared to snakes in the Caatinga (a semi-arid region in northeastern Brazil), with fossorial and cryptozoic species occupying morphological space that is not occupied in the Caatinga. Monte Carlo permutations from canonical phylogenetic ordination revealed a significant phylogenetic effect on morphology for Colubridae, Colubrinae, Viperidae, Elapidae, and Boidae indicating that morphological divergence occurred in the distant past. We conclude that phylogeny is the most important factor determining structure of this Neotropical assemblage. Nevertheless, our results also suggest a strong ecological component characterizes a peculiar snake fauna.

Ecomorphological analysis of the masticatory apparatus in the seed-eating bats, genus Chiroderma (Chiroptera: Phyllostomidae)

Recent data have shown that owing to their seed-predator capacity Chiroderma doriae and Chiroderma villosum trophically depart from all previously studied species within the canopy fruit-bat ensemble. In this paper, the hypothesis that morphological adaptations related to granivory have evolved in these bats is investigated and discussed. A canonical variate analysis was used to search for possible divergent trends between the masticatory apparatus of Chiroderma and other stenodermatines currently recognized in the same ensemble. A total of 142 specimens representative of eight species was included in the analysis. Species of Chiroderma can be discriminated from all other species in the sample based on the increased development of masseter-related variables (height of the anterior zygomatic arch, masseter moment arm, and masseter volume), which, in conjunction with other morphological characteristics (dentition and gape angle) discussed herein, corroborates the evolution of durophagy in this group. A complementary analysis based on a Mantel test revealed that the pattern of morphological differentiation that emerged from the canonical variate analysis does not agree with the one expected based solely on the phylogenetic relationships adopted for the canopy fruit-bats studied here. This result is consistent with the hypothesis that morphological adaptations related to granivory have evolved in Chiroderma.

Lagartos da Marambaia, um remanescente insular de Restinga e Floresta Atlântica no Estado do Rio de Janeiro, Brasil

Carvalho, A.L.G., Araujo, A.F.B. and Silva, H.R. Lizards of Marambaia, an insular remnant of Restinga and Atlantic Forest in the State of Rio de Janeiro, Brazil. Biota Neotrop. May/Aug 2007 vol. 7, no. 2. http:// www.biotaneotropica.org.br/v7n2/pt/abstract?inventory+bn03407022007. ISSN 1676-0603. This work presents the results of a survey of the lizard species that occur in Marambaia, RJ. Twelve species of lizards, distributed in seven families were registered. Teiidae is the richest family (3 spp.), followed by Gekkonidae (2), Scincidae (2), Tropiduridae (2), Gymnophthalmidae (1), Leiosauridae (1), and Polychrotidae (1). The lizard fauna of Marambaia is similar to that occurring in other localities in the southeastern coast of Brazil. Nevertheless, Marambaia harbors Cnemidophorus littoralis and Liolaemus lutzae, species restricted to restinga habitats in Rio de Janeiro State and considered under threat. The area also protects typical forest species, including the arboreal lizards Enyalius brasiliensis and Anolis cf. fuscoauratus. Forest and restinga are continuous in Marambaia and represent the richest habitats for lizards, comprising nine and eight species, respectively. The possibility of genetic variability loss due to the geographical isolation of the area, and the apparent difficulty of re-colonization in the case of local loss of diversity, added to environmental modifications caused by human activities, are worrying issues for the conservation of Marambaia herpetofauna.

Records of the rattlesnakes Crotalus durissus terrificus (Laurenti) (Serpentes, Viperidae) in the State of Rio de Janeiro, Brazil: a possible case of invasion facilitated by deforestation

This paper documents the presence of rattlesnakes, as an invasive species, in several municipalities of the State of Rio de Janeiro. As previous registers indicate, these snakes probably invaded at least the municipality of Valenca carried by floodwaters between the decades of 1950 and 1960. In the new environment, along the margins of the Rio Preto, these snakes were able to establish new populations in deforested areas turned into cattle grazing. The presence of rattlesnake in the municipality of Barra do Pirai, a municipality that has no border with Rio Preto, however, indicates that these snakes dispersal into new areas may be facilitated by open areas, represented by pastures, created after deforestations.

Feeding ecology of Tropidurus torquatus (Wied) (Squamata, Tropiduridae) in two areas with different degrees of conservation in Marambaia Island, Rio de Janeiro, Southeastern Brazil

We compared the effects of habitat disturbance on the feeding ecology of two local populations of Tropidurus torquatus (Wied, 1820) in restinga habitats on Ilha da Marambaia, Southeastern Brazil. Both populations presented a relatively diverse diet and differ in the number (DMax = 0.22, DF = 2, p = 0.00) and volume of prey consumed (DMax = 0.82, DF = 2, p = 0.00). Ants were the most frequent and numerous preys in both areas, and plant matter and coleopterans were the most important alimentary items in volume. The population from the disturbed area presented a larger niche breadth for number of prey items consumed (Binum = 3.06) and volume (Bivol = 2.98), when compared to the other population (Bjnum = 2.44, Bjvol = 1.52). Niche overlap was higher for number of items consumed between the populations (Oijnum = 0.82) but lower for volume (Oijvol = 0.05). Our data suggest dietary differences between the two lizard populations, and these differences may be associated with environmental modifications. Our main hypothesis to explain the dietary differences is based in the Optimal Foraging Theory. However, the alimentary behavior, and consequently the diet of these lizards, seems to be constrained phylogenetically, with a pattern that may have evolved in the ancestor of all iguanids.

THE CONSERVATION STATUS OF SNAKES IN CENTRAL BRAZIL

Abstract We assessed the conservation status of 61 species from a central Brazilian snake assemblage by ranking species according to their vulnerability to ten threat factors that are thought to influence the survival of snake populations. The anomalepidid snake Liotyphlops ternetzii whereas the species with the lowest risk and the colubrid Drymoluber brazili was the most threatened. Less than 15% of the Distrito Federal snake fauna was considered free from any threat. The natural-history of the species, its geographic distribution, and human attitudes were important factors in determining the levels of threat for central Brazilian snakes. Principal Component and Cluster analyses were used to classify species into vulnerability groups that were based on sharing similar threat factors. Thirteen groups were identified which classified species in categories ranging from no risk to threatened. Within Brazil, status assessments of additional snake assemblages in other biomes would be useful in generating a comprehensive conservation plan for the country.

Patterns of parasitism by Eutrombicula alfreddugesi (Oudemans) (Acari, Trombiculidae) in three species of Tropidurus Wied (Squamata, Tropiduridae) from Cerrado habitat of Central Brazil

This study concerns the patterns of parasitism by the larvae of Eutrombicula alfreddugesi (Oudemans, 1910) on three species of Tropidurus Wied, 1820 from Cerrado habitats of Central Brazil: T. oreadicus Rodrigues, 1987 (n = 97), T. itambere (n = 85) and T. torquatus (Wied, 1820) (two samples n = 75, n = 23). The highest prevalence value was observed in T. itambere (88.2%), followed by T. oreadicus (87.6%), and T. torquatus (17.3% and 65.2%). The most important sites of infestation were the mite pockets and skin folds, especially on the neck and inguinal region. Tropidurus itambere Rodrigues, 1987 was the most heavily parasitized species (mean intensity of infestation: 36.67 ± 41.09), followed by T. oreadicus (15.38 ± 21.08), and T. torquatus from Unai, Minas Gerais (12.13 ± 21.09). The lowest intensity of infestation was found in T. torquatus from urban and periurban areas of Brasilia, Distrito Federal (1.97 ± 5.43). The analysis did not indicate differences in intensity of infestation between sexes for any of the species. Differences in the patterns of parasitism among the three lizard species may be related to the morphological and numerical variation of the skin folds (especially mite pockets), to the degree of conservation of the hosts habitats, and to selective processes related to reduction of damage to the hosts bodies, to the evolution of mechanisms of decreasing illness transmission by parasites, or even to some behavioral traits of the lizards.

Morphometric study of Phragmatopoma caudata (Polychaeta: Sabellida: Sabellariidae)

The sabellariid Phragmatopoma caudata (Kroyer, 1856), Morch, 1863 is widely distributed in the Americas and constructs large reef agglomerates that provide substrates for other benthic species. However, the difficulty in obtaining size data (especially length) hampers population studies, making it necessary to carry out morphometric studies as basis for studies of population dynamics. The objective of the present study is to determine the best morpho- logical descriptor of length in P. caudata. A total of 17 morphometric variables were measured in specimens from four different populations. Measurements were performed using an ocular micrometer attached to a stereoscopic micro- scope. Correlations in the dataset were tested using Pearsons linear correlation coefficient, and the hypothesis of mor- phometric differences among populations was tested using MANOVA and principal component analysis. Correlation coefficients were different amongst populations, as well as in the measured traits . Moreover, the results suggest that populations differ more strongly in body size than in shape. Although populations presented different morphometric relationships, the length of the first thoracic chaetiger was one of the variables with highest correlation with total length. This result, as well as the fact that such region is located on the anterior portion of the body, suggests that this structure is a good length descriptor in P. caudata.

Amphibia, Anura, Parque Estadual do Cunhambebe, Itaguaí municipality, Rio de Janeiro state

We report a list of the amphibians from the Parque Estadual do Cunhambebe (22°54’07” S, 43°53’33” W) in Itaguai municipality, an area of Atlantic Rainforest in Rio de Janeiro State, southeastern Brazil. The work was carried out from January to November 2010. We recorded 28 species of anuran amphibians distributed in eight families: Brachycephalidae (3), Bufonidae (2), Craugastoridae (1), Cycloramphidae (2), Hylidae (13), Hylodidae (2), Leiuperidae (1) and Leptodactylidae (4). Adding the species recorded in the Parque Estadual do Cunhambebe in Mangaratiba municipality, the richness of amphibians in the park currently is now 47 species.