Three new species of Misionella from northern Brazil (Araneae, Haplogynae, Filistatidae)

Abstract Three new species of the genus Misionella are described from Brazil: Misionella carajas sp. n. and Misionella aikewara sp. n. from caves in the states of Pará and Tocantins and Misionella pallida sp. n. from natural and synanthropic dry areas in the states of Piauí, Maranhão, Rio Grande do Norte and Bahia. These species seem to belong to a distinct group within the genus; the males have an elongate palpal tibia and bulb, a pair of characteristic and hirsute macrosetae in the second metatarsus and the females have internal genitalia with only one pair of spermathecae, with relatively short ducts, lacking the auxiliary receptacles. Their phylogenetic placement and geographic distribution are briefly discussed.


Introduction
The genus Misionella Ramírez & Grismado, 1997 was established to include the species Filistata mendensis described by Mello-Leitão (1920) from Mendes, state of Rio de Janeiro, Brazil. This species is very common in southeastern Brazil and northeastern Argentina, where populations have synanthropic habits, living in the brick walls in houses or on tree bark near buildings or urban squares. Grismado and Ramírez (2000) described M. jaminawa, a second species from the state of Acre, in Brazilian Amazonia.
The species of the genus Misionella resemble those of Pikelinia Mello-Leitão in having enlarged male palpal tibia and second male metatarsi retrolaterally excavated, with short spinules (Figs 1-2) or with excavation absent, but having at least a pair of macrosetae (Fig. 1H). According to Ramírez and Grismado (2000) species of these genera differ by the absence of any projection in the male palpal tibia (Ramírez and Grismado 1997, figs 100-102) and by having two pairs of spermathecae placed side by side in the internal female genitalia (see Ramírez and Grismado 1997, Fig. 103) in Misionella. Following the original diagnosis presented by Ramírez and Grismado (2000) the species here described seem to belong to a distinct group in the genus Misionella. The males of these species lack an apophysis on the palpal tibia, have a characteristic pair of hirsute spines in the second metatarsus (Figs 1G-I) and the females have internal genitalia with only one pair of spermathecae with short ducts (Figs 8C,11C).
In this paper, we describe these three new, morphologically deviant species of Misionella from Brazil, two from caves in the states of Pará and Tocantins and a third from dry areas in the states of Piauí, Maranhão, Rio Grande do Norte and Bahia.

Material and methods
The material examined belongs to the following institutions: Descriptions follow Ramírez and Grismado (1997). Measurements are expressed in millimeters. Leg segment lengths were measured laterally. The illustrations were made in a stereomicroscope with camera lucida. For the illustration of female genitalia, we used dissected organs immersed in clove oil, following Levi (1965). Image stacks were obtained with a Leica M165 C stereoscopic microscope and extended focus images were generated using Helicon Focus 6 (www.heliconsoft.com); female spermathecae were digested with pancreatin and photographed in temporary mounts without a coverslip in lactic acid on an Olympus BH-2 compound microscope. Material for SEM was either air-dried or dehydrated using an ethanol series followed by immersion in HDMS, and sputter-coated with 10 nm of gold or gold-palladium. Micrographs were taken with a Quanta 250 the electron scanning microscope at Laboratório de Biologia Celular Instituto Butantan, LEO 1450VP of the Museu Paraense Emílio Goeldi, or a Philips FEI XL30 TMP at Museo Argentino de Ciencias Naturales "Bernardino Rivadavia".
Natural history. This species is very common in the Carajás area, where 352 adult specimens were collected. 101 males, 251 females and approximately 400 immature (only 164 included here) were sampled in 144 caves, between the years 2006-2010. The caves are formed in iron ore in areas of residual plateau, more specifically on the bases of outcrops of iron ore or 'canga'. The 'canga' are usually covered by open vegetation type called 'metalophylic vegetation', which is characterized by plants able to grow in soils rich in iron and other heavy metals (Pinto-da-Rocha and Andrade 2012; Carmo and Jacobi 2013). The specimens were found in lighter areas as well as in the darker areas of the interior of caves. They were always caught in the refuge of their irregular webs located on the ground and/or walls of the cavities (Figs 13A-C). Two types of refuges were found, one formed by tubes in the interior of the guano (Fig. 13C) and other, with irregular distribution of silk, in the walls or using the nest of wasps as substrate (Fig. 13D). The prey commonly observed were micro-Lepidoptera of the family Tineidae (Fig. 13A) and immature of Hemiptera of the genus Zelurus Silvestre (Reduviidae). Although the new species has been found only inside the caves, the specimens do not show any troglomorphism, except perhaps the elongate legs.
Distribution. The species seems to occur exclusively in caves in the region of the Flona of Carajás, in the municipalities of Parauapebas and Canaã dos Carajás (Fig. 14).  Etymology. The specific name is a noun in apposition and refers to the ethnic group of the region of São Geraldo do Araguaia, where the type locality is located: the Tupi indigenous group Aikewará.

Misionella aikewara
Diagnosis. Males of Misionella aikewara can be distinguished from M. carajas and M. pallida by the shorter palpal tibia and elongated paraembolic lamina (Figs 4E-G, 11D-E). Females can be recognized by the elongated receptacles curved distally and separated at the base (Fig. 11F).
Variation. 5 females: total length 3-4.5; carapace 1.4-2; femur I 1.7-2.2. Natural history. Eleven specimens were collected, only one male, eight females and two immature, in four limestone caves located in municipalities very close to the border of the states of Pará and Tocantins (Fig. 14). In general, the walls of the caves had high humidity with pools and/or running water therein. These caves have high number of micro-habitats such as roots, guano and crevices. The specimens of M. aikewara sp. n. were located in lighter areas as well as in the darker areas of the interior of caves. The webs are irregular, as in Misionella carajas sp. n., and the capture was always performed in the refuge of their webs located on the walls and cracks in the cavity (Fig. 13E). All specimens were found inside caves and do not show any kind of troglomorphism.
Natural history. This species has been collected several times in both natural and synanthropic habitats in northeastern Brazil. The species seems to naturally occur in Caatinga vegetation, a type of seasonally dry tropical forest. In synanthropic conditions, females can be found in their webs in the corners and cracks of windows and doors (L.S. Carvalho, pers. comm.). Males have been collected in pitfall traps in Caxias, in the state of Maranhão.

Discussion
Phylogenetic placement. The three new species herein described superficially resemble Filistatoides F.O. Pickard-Cambridge due to the elongate palps and bulbs, and by the female genitalia with a single pair of spermathecae (see Gray 1995;Ramírez and Grismado 1997). However, they share two derived states with the South American genera Pikelinia and Misionella: the cymbium fused to the tegulum (Fig. 6C, D) and the second metatarsus of males modified and bearing retrolateral macrosetae (Figs 1G-I, 2A, 4C-D, 5D-F, 7). Currently, Misionella is defined by the presence of a modified metatarsus II combined with the absence of a tibial apophysis in the male palp (Ramírez and Grismado 1997), both characters being present in the three new species. However, several undescribed filistatid species not treated here have intermediate morphologies between Misionella and Pikelinia (Magalhaes, unpublished data), blurring the limits between the two genera. The three species newly described apparently form a monophyletic group, supported by the unilobulate spermathecae, long bulbs, and the absence of pigment rings in the legs. Their placement in Misionella is not satisfactory, and a new genus could be proposed. However, as stressed above, the limits between South American filistatid genera are currently somewhat dubious, and several genusdefining characters are apparently homoplastic. A new phylogenetic analysis of the Filistatidae is in progress by the second author, and we think it is more prudent not to erect a new genus at the moment. Biogeography. Filistatids are known to occur mainly in arid and semi-arid environments. To date, Misionella have been an exception as they seem to prefer more humid habits: M. mendensis occurs in the Cerrado (a savannah) and the Atlantic Forest, and M. jaminawa is Amazonian (Ramírez and Grismado 1997;Grismado and Ramírez 2000). On the other hand, Misionella pallida sp. n. seems to be restricted to the western border of the Caatinga, a seasonally dry tropical forest with a semi-arid climate (Pennington et al. 2000). Misionella carajas sp. n. and M. aikewara sp. n. occur in the humid Amazon, but they are restricted to caves. Caves often have different microclimatic conditions than the surroundings, and sometimes harbor relict species (e.g. Malek-Hosseini et al. 2015). It has been hypothesized that the limits of the seasonally dry tropical forests of Brazil have changed in response to recent climatic fluctuations (Pennington et al. 2000;Magalhaes et al. 2014). Thus, it can be hypothesized that the ancestors of M. carajas sp. n. and M. aikewara sp. n. also lived in dry conditions, and that they reached their current distribution during an event of expansion of the dry forests, being subsequently 'trapped' in the caves as the dry forests receded. A dated phylogeny of South American prithine would help shed some light on these questions. and F. Tricárico, at the MACN Microscopy Laboratory of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", for SEM images. Thanks to Sergei Zonstein, an anonymous reviewer and Cor Vink for their comments on the manuscript. Robson Zampaulo provided information on caves and biology, and L.S. Carvalho provided specimens and natural history data of M. pallida. This study was financially supported by Vale S.A., OAPBio, CNPq 443270/2015-5 grant to IC, CNPq 301776/2004-0 and FAPESP 2011/50689-0 grants to ADB, a CONICET doctoral fellowship to ILFM and grants PIP 2012-0943 from CONICET and PICT 2011-1007 from FONCyT.