Navegando por Autor "COSTA, Maria Cristina dos Santos"

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Acesso aberto (Open Access)
Composition and ecological patterns of snake assemblages in an Amazon-Cerrado Transition Zone in Brazil
(Universidade Federal do Pará, 2015-06) PINHEIRO, Leandra de Paula Cardoso; ABE, Pedro Santos; BITAR, Youszef Oliveira da Cunha; CASTRO, Luiz Paulo Printes Albarelli de; COSTA, Maria Cristina dos Santos
The present study encompasses the species composition and ecological characteristics of the snake community in a Cerrado-Amazon transition zone in Midwest of Brazil (state of Mato Grosso). The data were collected during six excursions to the "Tanguro" (study area) by visual encounter survey, pitfall traps with drift fences and non-systematic sampling. We collected 194 specimens, distributed in 34 species, 26 genera, and eight families. The most abundant species were Crotalus durissus Linnaeus, 1758 (n = 50), Philodryas olfersii (Lichtenstein, 1823) (n = 15), Philodryas nattereri Steindachner, 1870 (n = 13), Xenodon rabdocephalus (Wied, 1824) (n = 12), Lachesis muta (Linnaeus, 1766) (n = 10) and Erythrolamprus almadensis (Wagler, 1824) (n = 10). The composition of species found here represents a combination of Cerrado and Amazonian savanna fauna.
Acesso aberto (Open Access)
Feeding ecology of Liophis reginae semilineatus (Serpentes: Colubridae: Xenodontinae) in eastern Amazon, Brazil
(2010-02) ALBARELLI, Luiz Paulo Printes; COSTA, Maria Cristina dos Santos
We studied the diet of Liophis reginae semilineatus (Wagler, 1824) from eastern Amazon, Brazil, based on the analysis of 182 preserved specimens. Thirty-six individuals had prey in their stomachs; 34 (95%) contained exclusively anurans and 2 (5%) contained both anurans and lizards. The most common prey items were small Leptodactylus sp. (33.3%), followed by Physalaemus ephippifer (Steindachner, 1864) (10.3%). Prey ingested head-first (78%; n = 25) were significantly larger than prey ingested tail-first (22%; n = 7). Females of L. reginae semilineatus have longer and wider heads than conspecific males with the same body length, which correspond to sexual divergences in the diet (size of the prey). No correlation was found between snake head length vs. prey size (SVL, width and mass). Liophis reginae semilineatus is an anurophagous snake that probably forages actively on the ground.
Acesso aberto (Open Access)
Geographical variation in the reproduction and sexual dimorphism of the Boddaert's tropical racer, Mastigodryas boddaerti (Serpentes: Colubridae)
(2013-10) SIQUEIRA, Débora Mendes; NASCIMENTO, Loana Pastana; MONTINGELLI, Giovanna Gondim; COSTA, Maria Cristina dos Santos
We obtained data on time of sexual maturity, dimorphism, fecundity and on the reproductive cycle of Mastigodryas boddaerti (Sentzen, 1796) through the examination of 321 preserved specimens, of which 221 were collected in the Brazilian Amazon region and 100 in the Cerrado savannas of Central Brazil. The degree of sexual size dimorphism (snout-vent length, SVL) was significantly greater in the specimens from the Cerrado in comparison with those from the Amazon. Females had a significantly larger number of ventral scales, on average, whereas males had more sub-caudal scales. However, there was no intersexual difference in tail length or head width, although the heads of the males were significantly longer, which may reflect dietary differences. Breeding females from the Amazon region contained between one and six eggs (N = 12, mean = 3.0), whereas two females from the Cerrado had four to six eggs (N = 10, mean = 5.0). No relationship was found between the SVL of the Amazonian females and the number of eggs or vitellogenic follicles they contained (Cerrado females were not analyzed here due to small sample size). Males are smaller than their female counterpart when they reach sexual maturity. Even though females from the Amazon reproduce throughout the year, females from the Cerrado breed seasonality.
Acesso aberto (Open Access)
Serpentes da Bacia Petrolífera de Urucu, município de Coari, Amazonas, Brasil
(Instituto Nacional de Pesquisas da Amazônia, 2010) PRUDENTE, Ana Lúcia da Costa; MASCHIO, Gleomar Fabiano; COSTA, Maria Cristina dos Santos; FEITOSA, Darlan Tavares
A structured snake inventory was carried out at the Base Operacional Geólogo Pedro de Moura (BOGPM), located at the Urucu Petrol Basin, Municipality of Coari, Amazonas, during 2003, 2004 and 2007. Throughout four sampling expeditions (51 collection days), seven species of snakes, belonging to seven families and 33 genera, were recorded. Four complementary sampling methods were used: pitfall traps with drift fence, occasional encounters, time-limited search on foot and time-limited search by car. Of the 47 collected species Liophis reginae (n= 14), Philodryas viridissima (n= 9), Philodryas boulengeri (n= 7) and Oxybelis fulgidus (n= 7) were the most abundant in the region. The highest number of species and specimens was obtained by the time-limited search by car (n=52.8%). Previous studies indicate that localities south of the Amazonas river (such as the eastern region of Pará and Tucuruí, state of Para, and Samuel Hydroelectric Plants, state of Rondônia) present a greater richness when compared to those north of the Amazonas river (such as the mucipality of Manaus, INPA-WWF Reserve and Balbina Hydroelectric Plant, state of Amazonas).Thus, it is possible to infer that the snake inventory in Urucu region is not yet complete, requiring more sampling efforts so that new records can be obtained for the area.
Acesso aberto (Open Access)
Species composition and reproductive modes of anurans from a transitional Amazonian forest, Brazil
(2012-02) BITAR, Youszef Oliveira da Cunha; PINHEIRO, Leandra de Paula Cardoso; ABE, Pedro Santos; COSTA, Maria Cristina dos Santos
The aim of the present study was to describe the species composition and reproductive modes of an anuran community from a transition area between the Amazonia and Cerrado biomes. Data were collected in habitats exhibiting different degrees of anthropogenic degradation. The community (35 species) identified during the present study presented a larger number of reproductive modes when compared with those from Cerrado communities, but smaller than those of other sites in the Amazon. While all nine modes were recorded in the gallery forests of local rivers and streams, anthropogenic habitats (rubber tree orchards and soybean fields) were occupied only by species adapted to environments where humidity is low, typical of the Cerrado. Overall, the anuran fauna of the study area was characterized by species that depend on access to water bodies for their reproduction, with only a few specialized species able to reproduce in dry environments.