ABSTRACT Phimophis guerini Duméril, Bibron & Duméril, 1854 is a Xenodontinae snake distributed in Argentina, Brazil and Paraguay. In Brazil, the species is broadly distributed, occurring mainly in open areas of the Cerrado, but also in the Amazon, Atlantic forest and Caatinga. We provide a new record for this species from the municipality of Santarém in the western portion of the state of Pará (Brazil). Five specimens were collected in a small area covered with Amazonian Savanna vegetation. We also provide the description of the morphological variation for the collected specimens. The new record extends the northern limit of the distribution by some 640 km (from Floresta Nacional de Carajás, Parauapebas municipality, eastern Pará). The record from Santarém provides a third locality for P. guerini within the Amazon biome and supports the hypothesis of a past ecological corridor linking the Cerrado and the open habitats within the Amazon.

ABSTRACT We describe the diversity, natural history and structure of snake assemblages from Marajó Island, state of Pará, Brazil, after analyzing 439 specimens deposited in herpetological collections. We tested the hypothesis that snake assemblages from forest and open areas of Marajó Island are distinct with regard to their structure, composition and functional groups. To compare the snake composition of the forest and open areas of Marajó with other comparable assemblages in Brazil, Principal Coordinate Analysis and Clustering tests were performed. A total of 61 species of snakes was recorded for Marajó, with ten species cited for the first time for the study area (Atractus natans Hoogmoed & Prudente, 2003, A. schach (Boie, 1827), Dendrophidion dendrophis (Schlegel, 1837), Helicops hagmanni Roux, 1910, Hydrops martii (Wagler in Spix, 1824), Lygophis meridionalis (Schenkel, 1901), Erythrolamprus typhlus (Linnaeus, 1758), Philodryas argentea (Daudin, 1803), Siphlophis cervinus (Laurenti, 1768), and Thamnodynastes sp.). The composition and structure of snake assemblages between forested and open were different, with five functional groups of snakes in forest areas, and three groups in open areas, based on habit and habitat. In all, 19 species were exclusive to forest areas, 10 were exclusive to open areas and 26 species were recorded in both areas. Our results revealed greater richness for forested areas, probably due to greater habitat heterogeneity. The species composition for forested area in Marajó was similar to that found in other Amazonian assemblages, while that for open areas was more similar to the Pantanal region than other open area assemblages. The general structure of the snake assemblage of Marajó was dominated by anurophagous, terrestrial and diurnal species. Terrestrial, arboreal and semi-arboreal snakes showed a seasonal offspring production pattern, while the pattern for aquatic and semi-aquatic species was aseasonal. The structure of assemblages was influenced by both historical and ecological factors.

Corallus hortulanus é uma serpente conhecida por apresentar grande variação no padrão de coloração e desenho. Apesar de estudos relacionados ao seu policromatismo, nenhum deles abordou a variação geográfica no padrão de cor desta espécie. O objetivo deste estudo foi descrever a variação cromática das populações de C. hortulanus na Calha sul do Rio Amazonas e verificar a correlação entre a distribuição geográfica e a variação encontrada. A partir da análise do padrão de desenho e cor de 112 espécimes de C. hortulanus procedentes dos interflúvios (área entre dois rios) da Calha Sul foram descritos seis morfotipos. Dos seis morfotipos descritos, a cor marrom-acinzentado e o padrão de desenho losango alongado foram os mais comuns entre as populações analisadas. Dois morfotipos apresentaram uma tendência de correlação com a distribuição geográfica, estando relacionados aos rios Madeira e Juruá, embora o número de amostras tenha sido pequeno. A distribuição dos padrões morfológicos de C. hortullanus na Bacia Amazônica revelou que existe fluxo gênico entre as populações, independentemente da distância geográfica e das barreiras naturais. Provavelmente, o padrão de cor e desenho seja uma resposta fenotípica às pressões nos diferentes ambientes ocupados pela espécie.

The Amazon tree boa Corallus hortulanus is known for featuring a wide variation in color pattern and design markings. Although there are studies on its polychromatism, none of them addresses the geographic variation in the color pattern of this species. The aim of this study was to describe the chromatic variation found in the populations of C. hortulanus from the southern Amazon Basin and its relationship with geographic distribution of the species. Analysis of both design markings and color patterns on 112 C. hortulanus specimens from the southern Amazon Basin interfluves resulted in the identification of six distinct morphotypes. Grayish-brown coloration and elongated diamond-shaped patterns were the most frequent patterns. Two morphotypes showed a tendency of correlation with the geographical distribution of those species found in Madeira and Juruá Rivers. The small sample size does not allow for a robust conclusion on the possible cause of geographic variation. The distribution of morphological patterns of C. hortullanus in the Amazon Basin suggest that there is gene flow between populations, regardless of geographical distance and natural barriers. The variation in color pattern and markings may represent a phenotypic response to the characteristics of different habitats occupied by the species.

This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS), pitfall traps with drift fences (PFT), and incidental encounters (IE). During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10), Liophis poecilogyrus (Schlegel, 1837) (n = 9), Liophis viridis Günther, 1862 (n = 8) and Thamnodynastes sp. (n = 8) were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2). The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.

Dois acidentes por coral verdadeira são descritos em Belém, Pará. O primeiro caso foi decorrente de envenenamento por Micrurus surinamensis, no qual a vítima necessitou ventilação mecânica por insuficiência respiratória. O segundo, causado por Micrurus filiformis, apresentou apenas manifestações leves. Ambos os pacientes receberam soro antielapídico específico e evoluíram sem complicações. Acidentes por coral verdadeira na região Amazônica são raramente descritos e podem cursar com um largo espectro de alterações, que variam desde quadros de envenenamento muito leves até manifestações com risco de óbito.

Two cases of proven coral snake bites were reported in Belém, Pará State, Brazil. The first case was a severe one caused by Micrurus surinamensis. The patient required mechanical ventilation due to acute respiratory failure. The second case showed just mild signs of envenomation caused by Micrurus filiformis. Both patients received specific Micrurus antivenom and were discharged without further complications. Coral snake bites are scarcely reported in the Amazon region and there is a broad spectrum of clinical manifestations, varying from extremely mild to those which may rapidly lead to death if the patient is not treated as soon as possible.

Um inventário estruturado de serpentes foi realizado na Base Operacional Geólogo Pedro de Moura (BOGPM), localizada na Bacia Petrolífera de Urucu, Município de Coari, Amazonas, nos anos de 2003, 2004 e 2007. Nas quatro expedições realizadas (51 dias de coleta) foram registradas 47 espécies de serpentes, pertencentes a sete famílias e 33 gêneros. Foram utilizados quatro métodos complementares de amostragem de serpentes: armadilha de interceptação e queda, encontros ocasionais, procura limitada por tempo a pé e procura limitada por tempo de carro. Das 47 espécies coletadas, Liophis reginae (n= 14), Philodryas viridissima (n= 9), Philodryas boulengeri (n= 7) e Oxybelis fulgidus (n= 7) foram as mais abundantes em toda região. O maior número de espécies e espécimes foi registrado pela procura limitada por tempo de carro (52,8%). Estudos anteriores indicam que as localidades ao sul do Rio Amazonas (como região Leste do Pará, Usina Hidrelétrica de Tucuruí, Estado do Pará, e de Samuel, Estado de Rondônia) apresentam maior riqueza quando comparadas às regiões ao norte do Amazonas (como Município de Manaus, Reserva do INPA-WWF e Usina Hidrelétrica de Balbina, Estado do Amazonas). Desta forma, é possível inferir que o levantamento das serpentes da região de Urucu ainda não esteja completo, sendo necessário um maior esforço de coleta para que novos registros sejam adicionados para a área.

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.

Survey of 30 stoniach and/or gut contents of the five species of Siphlophis Fitzinger, 1843 revealed predominance of mostly diurnal species of lizards. Remains of nocturnal prey and snakes were also found. For the first time, one frog and one bat are recorded as preys of one species (S. cervimis Laurenti, 1768). Predation on mollusks and birds is not confirmed herein.