Squamate Reptiles from municipality of Barcarena and surroundings , state of Pará , north of Brazil

The local climate is hot equatorial with Köppen classification type Am. The mean annual temperature is 27°C with minimal thermal amplitude. Annual rainfall exceeds 2,500 mm, with a rainy season between January and June and dryer months towards the end of the year (Souza and Lisboa 2005). The study area encompasses an area of about 1,316.2 km2 currently composed of secondary forests (copse) at different successional stages. Most of the primitive vegetation has been replaced by subsistence agricultural species by means of deforestation. Lowland forests, flooded forests, upland forests, sandy meadows and sandy river beaches also make up the plant cover of the municipality (Souza and Lisboa 2006).


Introduction
The herpetofauna of the Brazilian Amazonia encompasses about 78% of the reptile species from the whole Amazonia region (Ávila-Pires et al. 2007).A considerable part of the 721 reptile species occurring at Brazil (Bérnils 2010), is present in the Amazon Rainforest (Ávila-Pires et al. 2007) and these numbers are growing every year due to the regular descriptions of new species (e.g.Prudente and Santos-Costa 2006;Passos and Fernandes 2008;Santos Jr. et al. 2008;Zaher et al. 2008).
However, the gaps of knowledge concerning the Amazonian herpetofauna include several aspects like as composition and geographic distribution, endemism and population dynamics (Azevedo-Ramos and Galatti 2002).In addition, knowledge of species distribution enables descriptions patterns of geographic distributions and their ecological meaning (e.g.inferences of environmental variables; Silva-Jr et al. 2009) and/or historical events (Cadle and Greene 1993).
This study represents an important contribution towards the understanding of the Amazonian herpetofauna considering that the study area is located in the deforestation arc and that the Amazon Rainforest is one of the Brazilian biomes with the highest rates of deforestation of native forests (Nepstad et al. 1999).
Here we provide a checklist of the amphisbaenia, sauria and Serpentes species for an area of the Amazonia forest, located in the municipality of Barcarena, northeast of the state of Pará, Brazil.The species list was based on data obtained from the inventories of the herpetofauna conducted in Barcarena and the herpetological collection of the Museu Paraense Emílio Goeldi (MPEG).
L) Surroundings areas of Barcarena.In these areas we included specimens collected by incidental encounters where specific data and geographical coordinates are missing.
Sampling methods included pitfall traps with drift fences, time-limited searches, and incidental encounters (Martins and Oliveira 1998).The pitfall traps were installed in areas G, H and I in two distinct sets.The first set was a 300 m line, with thirty 60 L buckets, 10 m apart from one another and connected by a plastic fence guide.The second set consisted of four 60 L buckets, seven meters apart from one another connected by a plastic fence guide, forming a "Y" shape.In areas J and K we installed three sets of traps, each 100 m long, containing twenty paired 60 L buckets interconnected by a plastic fence guide, 10 m apart from one another.The traps were checked daily.
The buckets remained open until the end of each field trip.Thus, in total, each set of traps remained open for 37 days, totaling 2,544 bucket-hours.
The time-limited search was made in A to H areas.The search lasted 4 h per day (2 h in the morning and 2 h at night), and was done by two people.Thus, in total, each area had the same sampling effort of 336 man-hours (16 man-hours/day × 21 days).
Incidental encounters are represented by all specimens found in the study site that do not fit in the other two methods mentioned above, including specimens that had been run over.
We complete the data with specimens deposited in the Herpetological Collection of the Museu Paraense Emílio Goeldi (MPEG), between 1980 and 2000.

Results and Discussion
We recorded 59 species of squamate reptiles for the municipality of Barcarena and surrounding areas, belonging to 17 families and 44 genera represented by Amphisbaenia with one family (one genera and two species); Sauria with nine families (15 genera and 17 species); and Serpentes with seven families (28 genera and 40 species) (Table 1).Amongst the lizards, Polychrotidae with four species (23% of total number of species) and Teiidae with three species (17% of total number of species) were the families with highest species richness, followed by Gymnophthalmidae, Sphaerodactylidae and Tropiduridae with two species each (12% of total species).For the families Gekkonidae, Iguanidae, Phyllodactylidae and Scincidae only one species was recorded (6% of total species).
The most abundant species of lizards were Gonatodes humeralis, Anolis fuscoauratus, Kentropyx calcarata and Mabuya nigropunctata.Gonatodes humeralis, one of the most common lizards in the Amazon region, is diurnal and inhabits various types of environments (e.g.terra firme, floodplains, or igapó; primary or secondary forest; gallery forest).It is an abundant species in disturbed Amazonia Rainforest and gallery forests of Central Brazil (Ávila-Pires 1995; Vitt et al. 2008).Similarly to G. humeralis, Anolis fuscoauratus is commonly found in the Amazon region and in disturbed areas.This species is distributed throughout most of northern South America east of the Andes and the Atlantic Forest of eastern Brazil (Vitt et al. 2008).Kentropyx calcarata and Mabuya nigropunctata are heliothermic lizards that inhabit the interior of tropical rainforests, although they can often be found in forest edges and clearings.Both species have wide distribution throughout the Brazilian Amazonia, also occurring in the Brazilian Atlantic Forest (Vitt et al. 1997;2008).
For the family Amphisbaenidae only Amphisbaena amazonica and Amphisbaena mitchelli were recorded for the area.This low number is probably related to the fossorial habits of these species, which makes them difficult to sample.Amphisbaena amazonica can be found throughout the Brazilian Amazonia and in the southeast of Colombia (Gans 2005), and open areas of the Brazilian Cerrado (savannah-like vegetation) (Colli et al. 2002), whilst A. mitchelli is reported for the state of Pará (Vanzolini 2002).
In total, we collected 40 species of snakes distributed in seven families and 27 genera.The family Dipsadidae (sensu Zaher et al. 2009) with 17 species (41% of the total number) and Colubridae with 10 species (26% of the total number) had the highest species richness, followed by the families Boidae and Elapidae, with five species each (13% of the total).Only one species was recorded for the families Typhlopidae (Typhlops reticulatus), Aniliidae (Anilius scytale) and Viperidae (Bothrops atrox).
Bothrops atrox was the most abundant snake species in the region of Barcarena, followed by Oxybelis aeneus and Siphlophis cervinus.Although snakes are relatively The large number of records of Bothrops atrox for the studied region was expected because, according to Duellman (1978), Cunha and Nascimento (1978), Dixon and Soini (1986) and Martins and Oliveira (1998) this species is one of the most abundant in the Amazon region.
The low abundance of Typhlops reticulatus and Anilius scytale is due in part to the fossorial or semi-fossorial habit of these species, making it difficult to visualize and capture them.The record of Typhlops reticulatus is consistent with the known distribution, which extends from eastern and southern Venezuela (the whole northern part of South America east of the Andes) to the Brazilian Amazonia, as well as an isolated population in northeastern Brazil (Dixon and Hendricks 1979;Cunha and Nascimento 1993;Rodrigues and Juncá 2002).Anilius scytale is also a species commonly found in the Amazonia Rainforest (Dixon and Soini 1977;1986;Duellman 1978; Cunha and Nascimento   1978;1981;1993;Martins and Oliveira 1998;Maschio et al. 2007), although it has also been recorded in deforested areas, in areas of Cerrado (states of Goiás and Mato Grosso, Brazil), and in humid forest enclaves within the Caatinga region (State of Ceará, Brazil) (Silva-Jr 2001).
Of the 243 species of Squamata present in the Brazilian Amazonia (Ávila-Pires et al. 2007), 24% were recorded for the region of Barcarena and surrounding areas, for which the vast majority of snakes (71%), lizards (76%) and amphisbaenians (100%) was recorded in secondary forest and open disturbed areas.The primary forest was responsible for 23% of the species of lizards and 12% of the snakes, whilst in the other environments (Igarapés and beaches) 14% and 2% of snakes were recorded, respectively.
These results reflect the general state of environmental change that is occurring in the whole region, which is why this inventory is an important contribution to the knowledge and conservation of the Squamata fauna in the Amazon Rainforest biome.
List | Volume 7 | Issue 3 | 2011 Abstract: We present the first species list of squamate reptiles of the municipality of Barcarena and surroundings, in state of Pará, north of Brazil.The study area is dominated by secondary florest at different successional stages.The list was drawn up as a result of data obtained from specimens deposited in the Herpetological Collection of the Museu Paraense Emílio Goeldi and inventories of the herpetofauna conducted in the Barcarena region.This list comprises 17 families (Amphisbaenia: Amphisbaenidae; Sauria: Gekkonidae, Gymnophthalmidae, Iguanidae, Phyllodactylidae, Polychrotidae, Scincidae, Sphaerodactylidae, Teiidae, Tropiduridae; Serpentes: Aniliidae, Boidae, Colubridae, Dipsadidae, Elapidae, Typhlopidae and Viperidae), 44 genera and 59 species of squamate reptiles.Silva et al. | Squamata from Barcarena and surroundings, Pará, Brazil Check List | Volume 7 | Issue 3 | 2011

Figure 1 .
Figure 1.Map showing the city boundaries (dashed) of Barcarena, State of Pará, Brazil and the localities sampled in the region (A to K).

Figure 2 .
Figure 2. The environments sampled in the region of Barcarena and surroundings, State of Pará, Brazil.A, Primary forest; B, Disturbed area; C, Igarapé; D, Beach.