Ants (Formicidae) and Spiders (Araneae) listed from the Metropolitan Region of Salvador, Brazil

: We present an ant and spider species list from five localities of the Metropolitan Region of Salvador (MRS). The MRS is placed in an Atlantic Forest area classified as dense broadleaf forest, considered to be of high biological importance and priority for conservation. We determined 198 species of ants (8 of these are considered to be synanthropic and/or exotic), distributed across nine subfamilies. We determined 164 species of spiders (14 of them being synanthropic and/or exotic), distributed across thirty families. Therefore, this survey shows that the urban environment of the MRS still harbors a large number of native fauna species.


Introduction
Among the major causes of biodiversity loss are changes in natural environments caused by cities emergence (McKinney 2002, McKinney 2006, Faeth et al. 2011. Urban environments favor species that are adapted to degraded environments (McKinney 2006;Shochat et al. 2010;Faeth et al. 2011), although, they can also contribute to the maintenance of native biodiversity (Dearborn and Kark 2010;Kowarik 2011) and rare and threatened species as well (Lundholm and Richardson 2010;Kowarik 2011). For integrated urban planning (Niemela 1999), faunal inventories focusing on management and conservation of biodiversity are of remarkable importance (Byrne 2007) since the first step to conserve a certain area is, undoubtedly, to know its fauna and flora (Pearson 1994).
Regarding the fauna of urban environments, arthropods deserve main attention for several reasons: (1) they provide a picture of the global biological diversity of a certain area; (2) generally, these species have short reproductive cycles and rapidly respond to anthropogenic disturbances; (3) they are easily sampled; (4) they characterize different tropic levels and (5) they are important elements to infer sociologic, agronomic and economic conditions (McIntyre 2000). However, for arthropods, specifically ants and spiders, previous studies investigating patterns of distribution in urban habitats are scarce (McIntyre 2000, Pacheco andVasconcelos 2007;Faeth et al., 2011).
Ants add a large portion of the total animal biomass in most tropical terrestrial ecosystems (Hölldobler and Wilson 1990), representing a dominant group of invertebrates in tropical regions with 15,626 described species and subspecies (Bolton 2013). By feeding on a wide variety of living and dead organisms, ants play a Abstract: We present an ant and spider species list from five localities of the Metropolitan Region of Salvador (MRS). The MRS is placed in an Atlantic Forest area classified as dense broadleaf forest, considered to be of high biological importance and priority for conservation. We determined 198 species of ants (8 of these are considered to be synanthropic and/or exotic), distributed across nine subfamilies. We determined 164 species of spiders (14 of them being synanthropic and/or exotic), distributed across thirty families. Therefore, this survey shows that the urban environment of the MRS still harbors a large number of native fauna species. the following localities: Salvador, Lauro de Freitas, Simões Filho, Camaçari and Mata de São João. In Salvador, we also sampled vacant lots and gardens/residential backyards in residential areas. In the forest remnants we collected ants and spiders in a total of 100 sampling points, besides 20 points in vacant lots and others 20 in gardens/residential backyards (Table 1). Per sampling point we collected these invertebrates using: Winkler traps (50x50 cm samples of soil or leaf litter for 24 h), diurnal manual sampling (15 minutes) and entomological umbrella (three shrubs with 1 m² of fabric) (Bestelmeyer et al. 2000). We used the same sampling scheme and effort in the three habitat types (forests fragments, vacant lots and gardens/residential backyards).
Specimen collection was approved and received license

Ants
Previous studies (using different methodologies and duration of sampling) conducted in urban environments of the Atlantic Forest ecoregion recorded 86 (Munhae et al. 2009), 67 (Iop et al. 2009), 55  and 33 species (Dáttilo et al. 2011), 21 species in cities of the Amazonian rainforest (Marques et al. 2002) and 143 species in urban sites of Cerrado (Pacheco and Vasconcelos 2007). Besides revealing the highest record of ant diversity for an urban matrix in Brazil, this study presents an ant diversity similar and even higher to other studies conducted in natural habitats of the Atlantic Forest (Feitosa and Ribeiro 2005, Santos et al. 2006, Rosumek et al. 2008, Coelho et al. 2009, Figueiredo et al. 2012.
In the MRS, the subfamilies Formicinae, Myrmicinae and Ponerinae showed the greatest number of species that are among the subfamilies with the highest species richness in the world (Bolton 2013). It is worthy to note that this pattern is maintained in urban or disturbed natural sites (Iop et al. 2009, Dáttilo et al. 2011.

Spiders
In the MRS, we recorded 5.1% of the spider richness of Brazil ). Studies performed (using different methodologies and sampling time) in Atlantic Forest fragments inserted in urban centers recorded: 170 species in Salvador (Melo et al. 2011), 166 species in João Pessoa , 151 species in Recife (Peres et al. 2007) and 46 species in São Paulo (Candiani et al. 2005). A survey conducted in a fragment of Atlantic Forest in the RMS, but outside the urban matrix, found 130 species (Pinto-Leite et al. 2008). These results show that a richness of 164 species found in the MRS is rather similar to the values observed in other metropolis of the Brazilian Northeast.
In the MRS, Araneidae, Salticidae and Theridiidae presented the highest number of species. This group of spiders are among the richest spider families in the world (Platnick 2013), and particularly for non-natural areas or disturbed environments, the pattern is maintained (Candiani et al. 2005, Peres et al. 2007, Melo et al. 2011.

Synanthropic and Exotic Species
In the MRS, 22 species are synanthropic and/or exotic (Tables 2 and 3). This high number of species could be related to environmental disturbances originated by cities inserted in either biome (Kowarik 2011), which favor introduction and prevalence of non-native and synanthropic species (McKinney 2006). Such species are good competitors that efficiently exploite resources from urban or highly impacted environments (McKinney 2006).
Exotic ants recorded here originated, in general, from Asia or Africa (Delabie 1993), while introduced spider species are from Europe and Asia . In our survey, it is to be noted that the exotic ant Monomorium pharaonis Linnaeus, 1958 was not recorded, nor either the spider Physocyclus globosus Taczanowski, 1874. We know that these species are frequent in the state of Bahia (M. pharaonis) and at Salvador (P. globosus), where they are easily found in house interiors (Delabie 1993, Delabie et al. 1995, Brazil et al. 2005, however, these sites were not sampled in this study. Despite the high incidence of exotic and synanthropic ants and spiders recorded, these species only represented 6% of the total species collected in the MRS (362 ant and spider species). In conclusion, our survey shows that the urban environment of the MRS still harbors a large number of native fauna species.        Table 3. Spider species collected in the Metropolitan Region of Salvador between July and October of 2012 in the cities: Salvador (SA), Lauro de Freitas (LF), Simões Filho (SF), Camaçari (CA) and Mata de São João (MSJ). Habitats types: Forest Fragments (FF), Vacant Lots (VL) and Garden/residential Backyards (GB). *Exotic species. †Synanthropic species.