First record of Tmesiphantes Simon, 1892 (Araneae, Theraphosidae) in Peru: a new species and its phylogenetic placement

: The tarantula genus Tmesiphantes Simon, 1892 includes 20 valid species distributed in Argentina and Brazil. These spiders are distinguished from other Theraphosinae genera by the presence of an incrassate femur III, more evident in males, urticating hair types III and IV on the abdominal dorsum, few cuspules on the labium (0 to 30), maxillae with a maximum of 200 cuspules and sternum rounded. From recent examination of material from Peru, we discovered specimens that share all the morphological characters of Tmesiphantes , but did not fi t with any known species. In the present study T. intiyaykuy sp. nov. is diagnosed, described, and illustrated. This new species resembles T. caymmii in the circular patch with stiff setae on midventral abdomen but can be distinguished by the shape of the palpal bulb and spermathecae. Also, we performed a phylogenetic analysis using morphological characters to infer the taxonomic placement of the new species. The analysis included 26 terminal species and 36 characters. Representatives of Tmesiphantes formed a monophyletic group and T. intiyaykuy sp. nov. is close related with T. caymmii . A dichotomous identifi cation key and a geographic distribution map were constructed for recognized species of Tmesiphantes .


INTRODUCTION
Among mygalomorph spiders, Theraphosidae is the most diverse family with 1032 species known to date (World Spider Catalog 2022). Theraphosidae includes spiders commonly known as tarantulas, and are distributed worldwide mainly in tropical and subtropical areas. The subfamily Theraphosinae is endemic from the New World and comprises more than 60 formally genera described (World Spider Catalog 2022). This subfamily is a monophyletic group characterized by the following synapomorphies: presence of urticating setae type III, male palpal bulb with subtegulum extended over the tegulum, embolus with keels and tarsal clavate trichobotria in a straight row (Raven 1985, Pérez-Miles et al. 1996, Bertani 2001, Bertani & Guadanucci 2013, Guadanucci 2014, Fabiano-da-Silva et al. 2019. The genus Tmesiphantes Simon, 1892 belongs to the subfamily Theraphosinae and comprises small to medium-sized spiders with an incrassate femur III. Representatives of this genus are also recognized by the few cuspules (less than 30) on the labium and maxillae. In particular, males are characterized by the following combination of characters: tibial spur consisting of two separated (not fused) branches and a well-developed retrolateral branch, which can have a rigid spine on the apex, the prolateral branch shorter than retrolateral, and can have an adjacent short spine; and male palpal bulb embolus, which can be twisted or straight, bearing prolateral keels only (superior and inferior). Females are characterized by a spermathecae composed of two receptacula with a subapical constriction (Pérez-Miles et al. 1996, Yamamoto et al. 2007, Fabiano-da-Silva et al. 2019 Yamamoto et al. 2007;T. brescoviti (Indicatti et al. 2008); T. buecherli (Indicatti et al. 2008); T. caymmii Yamamoto et al. 2007;T. crassifemur (Gerschman & Schiapelli, 1960); T. guayarus; T. hypogeus Bertani et al. 2013;T. mirim Fabiano-da-Silva et al. 2015;T. mutquina (Perafán & Pérez-Miles, 2014); T. nordestinus; T. nubilus Simon 1892; T. obesus (Simon, 1892); T. perp Guadanucci & Silva 2012;T. raulseixasi;T. riopretano Guadanucci & Silva, 2012;T. uru (Perafán & Pérez-Miles, 2014), and T. yupanqui (Perafán & Pérez-Miles, 2014). At present, the genus Tmesiphantes is distributed along the major Brazilian biomes and northeastern Argentina in the Yungas ecoregion (Fabiano-da-Silva et al. 2019). Fabiano-da-Silva et al. (2019) diagnosed the genus Tmesiphantes as being distinguishable from other Theraphosinae genera by a distinctly incrassate femur III, more evident in males, and females of T. amazonicus, T. uru, and T. yupanqui; urticating hair types III and IV on abdominal dorsum; few cuspules on labium (0 to 30), up to 200 cuspules on maxillae and a rounded sternum. Additionally, the male palpal bulb embolus varies from straight to slightly curved with prolateral keels only (superior and inferior), which follows the torsion of the embolus; the tibial apophysis consists of two separated (not fused) branches: retrolateral and prolateral branches (absent in T. guayarus). Finally, females possess spermathecae composed of two long and slender receptacles, always with a conspicuous subapical constriction at the subapical region.
From the examination of material deposited at the Museo de Biodiversidad del Perú, a new species of Tmesiphantes was discovered, and is herein described and illustrated. Moreover, a new phylogenetic approach including this new species, and discussion of its position, is presented. This is the most western record of the genus Tmesiphantes in South America and the first record for Peru.
The material examined in the present study is deposited in the MUBI, Museo de Biodiversidad del Perú (curator: José A. Ochoa).
All measurements are in millimeters. Total length was taken from the dorsal view and does not include the chelicera and spinnerets. Carapace length was measured from the clypeus margin to the posterior margin. Palp and leg segments were measured between the joints in dorsal view: femur, patella, tibia, metatarsus, and tarsus. The male palpal bulb and female spermathecae were dissected and stored in small vials containing 70% ethanol. Legs measurements were taken with a digital caliper to the nearest 0.001 mm and other measurements and photographs were obtained with a Zeiss Stemi 305 stereomicroscope, Zeiss AxioCam, and ZEN Imaging software v.

Cladistic analysis
Cladistic analysis was based on the previous matrix of the genus Tmesiphantes used by Fabiano-da-Silva et al. (2019) with some modifications. The original matrix was modified to include two new characters (35, 36) related to the keels on the embolus and some taxa used as outgroups were also modified. The only outgroup taxon kept from the original matrix was Iridopelma hirsutum Pocock, 1901 (subfamily Aviculariinae). The species used as new outgroups were selected based on their phylogenetic relationships with Tmesiphantes as previously suggested (Pérez-Miles et al. 1996, Yamamoto et al. 2007, Fukushima et al. 2008, Perafán & Pérez-Miles 2014, Fabiano-da-Silva et al. 2019: Catumiri argentinense (Mello-Leitão, 1941) (subfamily Ischnocolinae); Cyriocosmus sp.; Grammostola doeringi (Holmberg, 1881); Homoeomma uruguayense (Mello-Leitão, 1946); Iridopelma hirsutum; and Plesiopelma longisternale (Schiapelli & Gerschman, 1942). A data matrix composed of 36 morphological characters and 26 taxa has been constructed ( Table I 1.5 (Goloboff & Catalano 2016), under maximum parsimony. Multistate characters were treated unordered and follow binary coding, except for characters 13, 17, and 28. Parsimony analysis was made using implied weighting and to decide upon appropriate k-values, we followed the proposal by Mirande (2009) as implemented by Fabiano-da-Silva et al. (2019) for the cladistics of the genus Tmesiphantes. Thus, we selected the commands 3, 10, 70, 95, and 7 for the script iw.run. Nodes without support were collapsed and only best trees were kept. Character optimization and tree editing were performed with the computer software Winclada- ASADO 1.61 (Nixon 2004).

)…………..…………..Tmesiphantes caymmii
Palpal bulb with prolateral inferior keel not serrated (Fig. 4c-e), retrolateral branch of tibial apophysis about equal size of prolateral branch (Fig. 3g-h 1. Presence of a circular patch of short stiff setae on midventral abdomen (Fig. 5e) 2. Receptacles larger than the base with a strong subapical constriction (Fig. 5g), labium with more than 20 cuspules (Fig. 5c) Receptacles of constant width along their length (Yamamoto et al. 2007, Fig. 19), labium with 15 cuspules or less (Yamamoto et al. 2007, Fig. 18 Diagnosis. Differs from the all known species of Tmesiphantes (except from T. caymmii) by the presence of a circular patch of short stiff setae on midventral abdomen (Fig. 3f, 5e). Male differs from T. caymmii by the aspect of the palpal bulb, with inferior prolateral keel (PI) and superior prolateral keel (PS) not so distanced between them and PI not serrated (Fig. 4c-e) (serrated in T. caymmii, Fig. 14-16, Yamamoto et al. 2007), embolus shorter and stout and with a welldeveloped apical keel (A) (Fig. 4c-e) (absent in T. caymmii, Fig. 14-16, Yamamoto et al. 2007), and prolateral branch of tibial apophysis almost the same size as the retrolateral one ( Fig. 3g-h) (prolateral branch much smaller than retrolateral one in T. caymmii, Fig. 17, Yamamoto et al. 2007). Female can be distinguished from the remaining species of Tmesiphantes by the aspect of the spermathecae, which is short with separated (not fused) base, not inclined to the outer side with a strong subapical constriction located near the base. In addition, female differs from T. caymmii by a higher number of labial cuspules with about 30 (15 cuspules in T. caymmii).
Etymology. The specific epithet intiyaykuy means "west" or "sunset" in Quechua language, because the species has its westernmost geographical distribution recorded for the genus.
Distribution and natural history. Tmesiphantes intiyaykuy sp. nov. is known from Cconoc (Fig. 6, 7) and Chilhuismi, Department of Apurimac, Peru, at elevations between 1840-3363 m a.s.l, both are separated by 52 km in a straight line. Specimens were collected during dry and wet season, in stony and rocky areas, relatively flat, with sandy and clayey areas on the river bank of the Apurimac River. The retreat was sparsely-silked under a large angular rock lying on the surface of the ground among low scrub brush and Pepsis sp. (Pompilidae) were observed hunting Tmesiphantes intiyaykuy sp. nov. (R. West 2017, pers. com.). This species inhabits Inter-Andean dry forest, with presence of low forests, with dense to semi-open deciduous canopy 10-15 meters high, with numerous saplings, shrubs and bushes, with several tree and shrub cacti. The common floristic composition includes the genus Acacia, Anadenanthera, Aralia, Caesalpinia, Cedrela, Eriotheca, Erythrina, Eriotheca, Escallonia, Fourcraea, Kageneckia, Poissonia, and Prosopis. In general, the habitat has human settlements along the main road, and agriculture activities. The taxa from clade A share the keels on embolus oriented in a 90° angle with the proximal-distal axis of the bulb and those from clade B are characterized by a long embolus inserted in a straight orientation into the tegulum and PS and PI keels not pronounced. The clade C (Tmesiphantes raulseixasi, T. perp, T. nubilus and T. amadoi) appeared as monophyletic only in one tree (Fig. 1a) and the species share the embolus with two curvatures (spiral shape). The remaining species that do not show the synapomorphic character state of clades A, B and C were T. amazonicus, T. aridai, T. buecherli, T. bethaniae, T. caymmii, T. intiyaykuy sp. nov. and T. riopretano, thus they did not fall into any of these groups. This was also reported by Fabiano-da-Silva et al. (2019)    variation makes difficult to achieve any decision regarding their phylogenetic position. The new species described in the present work, Tmesiphantes intiyaykuy sp. nov. and T. caymmii are sister groups supported by the presence of a circular patch with stiff setae on midventral abdomen and this relation was supported in all trees (Fig. 1).

DISCUSSION
This close relation was not expected given the geographic distribution of clades and species (Fabiano-da-Silva et al. 2019). The distance among these two species is about 3,600 km and they occupy very distinct habitats, Figure 6. Tmesiphantes intiyaykuy sp. nov., habitat at type locality.