Diversity of scorpions ( Chelicerata : Arachnida ) in the Atlantic Forest in Pernambuco , northeastern Brazil

This study was conducted to measure the biodiversity of scorpion species in the remnants of the Brazilian northeastern Atlantic Forest, an important center of biodiversity and endemism. Collections were performed in twelve forest fragments in Sirinhaem municipality, Pernambuco State, through active searches at night by using UV lamps between 19:00h and 21:00h during the new moon phase in December 2012 and January 2013. A total of 1,125 specimens from two genera and five species were collected: Tityus pusillus Pocock, 1893; Ananteris mauryi Lourenco, 1982; Tityus brazilae Eickstedt & Lourenco, 1984; Tityus neglectus Mello-Leitao, 1932; and Tityus stigmurus (Thorell, 1876), all belonging to the family Buthidae C.L. Koch, 1837. The most abundant species was T. pusillus (90.7%), followed by A. mauryi (7.1%). Tityus brazilae , T. neglectus, and T. stigmurus together represented less than 3% of the individuals sampled.


Introduction
There are approximately 1,900 known species of scorpions (Stockman and Ythier 2010) that are distributed worldwide except in Antarctica (Sissom 1990).Approximately 50% of these species occur in Neotropical regions (Lourenço 2002a), including Brazil, where roughly 130 species are recorded (Porto et al. 2010).Although scorpions constitute a successful group of invertebrates in all environments where they live, the group is poorly sampled and little is known about their diversity in most ecoregions, particularly in the Brazilian Atlantic forest (Dias et al. 2006).The Brazilian Atlantic Forest, an important center of biodiversity and endemism, has suffered a significant loss of its native vegetation cover and currently has only a few remnant fragments of its original forest.These fragments are isolated from one another and are mostly surrounded by crops or pasture land (Mittermeier et al. 2005).Approximately 83% of the remnant fragments are <50 ha and only 1% are >100 ha (Ribeiro et al. 2009).They are composed of secondary forests with different levels of regeneration (Ribeiro et al. 2009).Although predators regulate many arthropod populations and can be food for invertebrates and vertebrates (Polis 1990), few ecological surveys highlighting scorpion species composition in the remnants of the Atlantic Forest have been performed (Dias et al. 2006;Yamaguti and Pinto da Rocha 2006;Bertani et al. 2008;Porto et al. 2010;Lira et al. 2013;Porto et al. 2013).Most studies on arthropod diversity in this environment have been restricted to insects (Santos et al. 2012;Souza et al. 2013), spiders (Melo et al. 2011), and harvestmen (Resende et al. 2012a(Resende et al. , 2012b)).
Since no taxonomical or ecological records on scorpion fauna were available from the Brazilian northeastern area.The scorpions were located by actively searching for them between 19 h and 21 h for one night for each remnant.Each transect was covered twice (round-trip) for 1 h by a pair of collectors equipped with ultraviolet lights (Figure 2).Active searches were made during the new moon phase, from December 2012 to January 2013 (the dry season).Each scorpion collected was individually stored in a vial containing 70% ethanol.The specimens were identified according to Lourenço (2002b).Voucher specimens (CA-UFPE #601 to 623) were deposited in the Arachnological Collection of the Universidade Federal de Pernambuco, Recife.All scorpions were collected by the permission of Instituto Chico Mendes de Conservação de Biodiversidade (ICMBIO) #36336-1.The data corresponded to active individuals in the leaf litter, barks, logs, and bromeliads.Specimens were either outside or just emerging from the refuges, as suggested by McReynolds (2008).

Results
A list of species and their occurrences is presented in Table 1.A total of 1,125 scorpions were collected.They were from two genera and five species, all belonging to the family Buthidae C.L. Koch, 1837.Four species were from the genus Tityus C.L. Koch, 1836 (T.brazilae Lourenço & Eickstedt, 1984;T. pusillus Pocock, 1893;T. neglectus Mello-Leitão, 1932;T. stigmurus (Thorell, 1876) and one belonged to the genus Ananteris Thorell, 1981(A. mauryi Lourenço, 1982).Photographs of the collected species are shown in Figures 3  and 4. Tityus pusillus and A. mauryi were recorded in all twelve fragments (Table 1).The former was the most common species, representing 90.7% of the total collected scorpions, followed by A. mauryi, representing 7.1%.The other three species together represented only 2.2% of the scorpions collected.The least common species was T. stigmurus, which was found only in one fragment.No single fragment had more than three scorpion species (Table 1).
Tityus pusillus and Ananteris mauryi were collected exclusively in the leaf litter, while T. brazilae was found under bark in cracks, and inside their retreats showing extended pedipalps and open chela.T. neglectus and T. stigmurus were found in logs and leaf litter.

Discussion
In northeastern Brazil, 28 species of scorpions are found.Sixteen species have been recorded in the Atlantic Forest (Lourenço 2002b, Dias et al. 2006;Porto et al. 2010).In this study, one-third of these species was found in Pernambuco.Dias et al. (2006) found four scorpions species in an urban Atlantic Forest fragment, all of which were also found in this study.
Tityus pusillus was the most common species in all fragments analyzed in the present work.The sedentary habit and microhabitat preference of the surface litter of this species are in agreement with Lira et al. (2013) and may facilitate sampling by active search, making this species more visible and easier to capture.Tityus pusillus  has also been recorded in the Atlantic Forest of Bahia (Porto et al. 2010, Brazil and Porto 2011) and Paraíba (Dias et al. 2006), as well as in the Caatinga (Bahia and Piauí) (Porto et al. 2010, Brazil andPorto 2011).These findings indicate a wide distribution of this species in the northeast region and a high ecological plasticity, since they were recorded from different environments such as rain forest and dry forest.
Ananteris mauryi, the second most common species in the present work, shows an errant habit, inhabiting the lower layers of leaf litter, as described previously by Lira et al. (2013).They also show metasomal autotomy (Lira et al. 2014).This species was originally described from PEC.Later, it was found in the states of Bahia and Sergipe (Lourenço 2002b;Brazil and Porto 2011).Using  Tityus brazilae was found in four out of the twelve fragments.A previous study reports its presence in the Atlantic Forest from Rio de Janeiro to Paraíba (Brazil and Porto 2011).We observed a sit-and-wait behavior with extended pedipalps and open chela, which corroborated with the observations of Lira and DeSouza (2014).Despite their large size (50-70 mm) (Lourenço 2002b), this behavior makes them difficult to be seen and captured.Therefore, it is likely that their presence and abundance are underestimated.

FRAGMENTS AREA SCORPION SPECIES Ananteris mauryi Tityus brazilae Tityus neglectus Tityus pusillus
Another large species (54-78 mm), Tityus neglectus, was found in three out of the twelve fragments.This species has a wide distribution in the northeast, and occurs from the state of Bahia to Rio Grande do Norte (Lourenço 2002b;Santos et al. 2003;Dias et al. 2006).It is associated with bromeliads and soil (Lourenço and Eickstedt 1988;Santos et al. 2003).Despite the specificity of its microhabitat described in the literature, specimens collected in this study were collected from the leaf litter or logs.This suggests that sampling may have occurred during the reproductive period when individuals leave their microhabitats in search of mates.We also collected more males than females, which supports this hypothesis (data not shown).
Tityus stigmurus was the least common species and it was collected from the smallest fragment.Which may represent the less conserved.As a synantropic scorpion, this species may be adapted to a more disturbed environment.This species is found in most northeastern states of Brazil and Minas Gerais (De Souza et al. 2009;Brazil and Porto 2011).It has been responsible for the highest number of scorpion stings in the region, including child mortality (Albuquerque et al. 2013).
Despite the great difference in size of the fragments, there were no distribution patterns among scorpions.No scorpion species was found only in the larger fragments and no fragment contained more than three species.Unlike other groups, such as dung beetles and ants, where the fragment size is important for species richness (Filgueiras et al. 2010;Leal et al. 2012), environmental quality seems to be more important for scorpions.However, further studies are needed to confirm this.Polis (1990) suggests that the presence of six species is an indicator of high scorpion diversity.Therefore, the five species reported in the Trapiche landscape suggests high scorpion richness in this area.This fact underscores the importance of conservation of forest remnants to maintain scorpion fauna.Thus, the results presented here contribute to the knowledge of the diversity of scorpions in the Atlantic forest of Pernambuco and can serve as a basis for future research on the impact of fragmentation on the population, distribution, and ecology of scorpions.

Figure 1 .
Figure 1.Map showing the distribution of forest remnants in Trapiche Mill and the position of the 12 studied fragments.