The species of Grammostola (Araneae: Theraphosidae) from Central Argentina: taxonomy, distribution, and surface ultrastructure of coxal setae

Abstract

Three species of Grammostola (Araneae, Mygalomorphae, Theraphosidae) from central Argentina are redescribed and illustrated and their geographic distributions are reported. A new synonymy between G. vachoni Schiapelli & Gerschman 1961 and G. schulzei (Schmidt 1994) n. syn. is proposed. We did not find zones of co-occurrence with the three species but, in several localities, we found two Grammostola species in sympatry. The surface ultrastructure of three types of coxal setae was studied by scanning electron microscopy (SEM). Two morphological types of spiniform setae were found on the coxae. The first type consisted of short and strong piriform setae, with the surface completely covered by ridges, and the second type consisted of long and thinner spiniform setae, with a piriform basal portion. The basal portion of the setae had ridges, the central portion was smooth and the apical zone had numerous short barbs with curved tips. The different types of setae found in these Grammostola species are clearly distinguished, and could be new useful character to diagnose at least these species. In combination with other characteristics, these characters could probably help to solve the problems in other species of this difficult genus if not also other genera.

The genusGrammostolaSimon 1892 (Araneae: Theraphosidae): a new species from western Argentina, new synonymy and distributional data

“…Previously known from mountains and southeast of Córdoba, Mendoza; in hilly systems of Ventania and Tandilia and meadows in southern Buenos Aires Province; in a hilly system of La Pampa; north and central Río Negro ( Figure 3E) and northeast of Chubut (Ferretti et al 2011). In this contribution: south of Santiago del Estero Province, where some of the mountainous system of the Sierras Pampeanas extended to this Province; mountainous systems of La Rioja Province and San Luis Province ( Figure 3C).…”

“…Males can be recognized from all Grammostola species by a small bristle of erected and stiff setae at the palpal tarsi ( Figure 1G). Additionally, it differs from G. burzaquensis by the absence of the smooth setae on the prolateral and retrolateral aspects of legs and retrolateral palpal maxillae, and by the presence of curved spermathecal receptacles (Ferretti et al 2011). It can be distinguished from G. vachoni by its small size, the shape of the palpal bulb and the absence of the stiff spiniform setae on the prolateral and retrolateral aspects of legs and retrolateral palpal maxillae.…”

“…Grammostola vachoni can be recognized by the following combination of characters: presence of short stiff and long spiniform setae on prolateral and retrolateral coxal aspects of legs I-III, prolateral coxae IV and retrolateral palpal maxillae; male palpal bulb pyriform with narrow bulb base, PI and PS developed, curved and long embolus, bent at the mid portion and strongly bent at the apical portion ( Figure 3A, B); two short and curved spermathecal receptacles; coloration (in vivo) black with prominent lines on patella and numerous long yellowish setae on ventral faces of all legs (Ferretti et al 2011) ( Figure 3D). …”

“…The genus Grammostola Simon 1892 inhabits temperate South America and currently includes 20 species described from Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay (Platnick 2012). This genus represents a taxonomic challenge despite some recent publications (Schmidt 1994a(Schmidt , 1999Ferretti et al 2011). described Grammostola fossor Schmidt 2001 as a new fossorial species from Río Negro Province, Argentina on the basis of male and female specimens collected in 1998 from Cerro Colorado, Sierra Colorada.…”

“…described Grammostola fossor Schmidt 2001 as a new fossorial species from Río Negro Province, Argentina on the basis of male and female specimens collected in 1998 from Cerro Colorado, Sierra Colorada. This locality is approximately 150 km from where Grammostola vachoni Schiapelli and Gerschman 1961 is distributed (Ferretti et al 2011). In a recent study of specimens from the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN-Ar) collection, we compared specimens of Grammostola from southern Argentina with the types of Grammostola vachoni and Grammostola fossor.…”