First record of Stenochrus portoricensis Chamberlin , 1922 ( Arachnida : Schizomida : Hubbardiidae ) for caves in Brazil : evidence for a troglophile status of an exotic species

New records of Stenochrus portoricensis Chamberlin, 1922 are given, the first south-american record in caves and the first to Goiás state in the Cerrado phytogeographical domain. Records of nine specimens (all females) in isolated regions from surface environment and deep zones in the cave suggest the status of troglophile (facultative cave-dwelling organisms) to this species. All specimens were found in places well preserved, without anthropization, differently from the observed to other records of the species in Brazil. Finally, we reinforce the need of replications on inventory studies of subterranean fauna.

The order Schizomida Petrunkevic, 1945 comprises 46 genera and 274 species, distributed in two families: Protoschizomidae and Hubbardiidae.The most widespread and speciose family is Hubbardiidae, with 44 genera and 249 species (Harvey 2011).Among the so-called smaller arachnid orders, schizomids are the most diverse (Harvey 2007).These arachnids are distributed worldwide in tropical and subtropical regions (Tourinho and Kury 1999).
There are 13 species of schizomids recorded in Brazil, distributed in five genera mainly in Amazonian region (Armas 2010;Santos et al. 2013).Stenochrus portoricensis Chamberlin, 1922, is one of these species, originally described from Mexican and Caribbean regions and found in other countries, such as Nicaragua, USA, Bermuda, Dominican Republic, Colombia, Virgin Islands.However, this species has been recorded in other regions as well as in greenhouses in England, Czech Republic, Slovakia and Poland, where S. portoricensis is considered an exotic species (Christophoryová et al. 2013;Zawierucha et al. 2013).In Brazil, S. portoricensis can be found in anthropized places in São Paulo, Rio de Janeiro and Bahia states, close to Atlantic Forest fragments or in its boundaries, in humid habitats and also in urban areas (Tourinho and Kury 1999;Santos et al. 2008;Kury et al. 2010).For central Brazil, we have records at Tocantins state, and, in this case, many individuals were recorded in very anthropized places, typical urban area (Kury et al. 2010).Considering the occurrence in subterranean environments, S. portoricensis has been recorded in Cuba, Belize, Guatemala, Jamaica, Puerto Rico and Mexico (Reddell 1997).Our record represents the first one for caves in South America and the first one for Goiás state.
We recorded the species within the limits of Terra Ronca State Park (46°10′-46°30′ S, 013°30′-013°50′ W), in São Domingos county, Goiás state, central Brazil (Figure 1).The region lies in the Cerrado phytogeographical domain (the savannah-like vegetation) interspersed by fragments of dry vegetation (Caatinga).The climate is characterized by a tropical semi-humid with four to five dry months per year (Nimer 1989).São Domingos is a carbonate karst area with continuous limestone outcrops and huge cave systems, reaching 30 km of development (linear measurements).After three collecting occasions, we recorded S. portoricensis in a single cave from São Domingos karst, the Terra Ronca II cave, part of a huge cave system named Terra Ronca-Malhada (Figure 2).Terra Ronca II cave has more than 7 km of extension, crossed by a subterranean river and many bank rivers with available micro-habits for fauna establishment.Specimens were collected in the twilight (crepuscular light) and aphotic (permanent darkness) zones, in sectors isolated from the epigean (=superficial) environment.The collections were carried out in the beginning of the rainy season (October 2012).We found the specimens in humid bank rivers, under small rocks with soil composed by sand, silt and vegetal debris, in an extremely humid environment (relative air humidity > 80%).In total, nine individuals (all females) were collected through visual inspection and fixed in ethanol 70%.
Specimens were examined under stereoscope and verified in relation to the diagnosis of the species.Reference material was consulted.Illustrations (photography) were taken with a FujiFilm X10 attached to a Leica MZ16 stereoscope (Figure 3a and 3b) and Olympus BX40 microscope (Figure 3c

NOTES ON GEOGRAPHIC DISTRIBUTION
such a preserved habitat, which suggests the need for more careful collections searching for these tiny arachnids.Indeed, we emphasize the necessity of more replications in the collections, since we recorded this population after the third occasion visiting the Terra Ronca II cave.

ACKNOWLEDGMENTS
We wish to thank Camile Sorbo Fernandes, Tamires Zepon, Luíza Bertelli Simões and our field guide, Ramiro Hilário, for helping in field work.Grupo Bambuí de Pesquisas Espeleológicas (GBPE) allowed the use of Terra Ronca-Malhada cave system map; Camile S. Fernandes edited Figure 3a New record: This record represents the first one for Goiás state, Brazilian caves and occurrence in transitional vegetation (Cerrado-Caatinga transition).Considering the records in caves and epigean environment around the world, the large distance from the cave entrance and also the high abundance, S. portoricensis must be considered a troglophile, a facultative cave-dwelling, at least for the São Domingos karst area.Indeed, the specimens were recorded in a very preserved cave, without any apparent impact, such as deforesting or pollution of soil and watercourses and without touristic activity.This is the first occasion that this exotic species is recorded in ; Diego M. von Schimonsky provied the map of cave location.MEB thanks the financial support of Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, process number 22.952262°, -43.160867° alt.2-15 m.Standard abbreviations cited are: UFSCar (Universidade Federal de São Carlos); MNRJ (Museu Nacional, Rio de Janeiro); LES (Laboratório de Estudos Subterrâneos).