Plator soastus sp. nov. of the spider family Trochanteriidae Karsch, 1879 is described and illustrated on the basis of female specimens collected in the Swat Valley, representing the first record of the genus in Pakistan and its (north) westernmost record for the whole known range. Material of both sexes of P. pandeae Tikader, 1969 from northern India is also illustrated, and new morphological terms are proposed for certain sclerites of the male palp.
Trochanteriidae Karsch, 1879 is a small family of spiders, currently comprising 50 extant species in six genera, primarily distributed in the pantropical regions, as well as 30 fossil species in six extinct genera from Baltic, Dominican, Rovno and Chiapas ambers (Dunlop et al., 2020; World Spider Catalog, 2022; Azevedo et al., 2022). Trochanteriids have a strongly flattened body, relatively elongated trochanters and noticeably laterigrade legs, and are typically found under bark or stones (Jocqué & Dippenaar-Schoeman, 2006). In Asia, the family is represented by a single genus, Plator Simon, 1880, with 16 species distributed from India to Japan (World Spider Catalog, 2022). Recently, we had the opportunity to examine some material of this genus collected in Pakistan, which represent a new species described and illustrated in this paper. Furthermore, based on material of P. pandeae Tikader, 1969 collected in northern India and using scanning electron microscopy, we propose new terms for certain previously unnamed sclerites of the male palp.
MATERIAL AND METHODS
Specimens were photographed using a Canon EOS 7D camera attached to an Olympus SZX16 stereomicroscope, and a JEOL JSM-5200 scanning electron microscope at the Zoological Museum of the University of Turku. Digital images were stacked using CombineZP and edited using CorelDraw graphic design software packages. Lengths of leg segments were measured on the dorsal side and listed as: total length (femur, patella, tibia, metatarsus, tarsus). The map was prepared using SimpleMappr (Shorthouse, 2010). The material examined is deposited at the Muséum d'histoire naturelle, Genève, Switzerland (MHNG) and at the Manchester Museum of the University of Manchester, UK (MMUE).
Family Trochanteriidae Karsch, 1879
Genus Plator Simon, 1880
Type species: Plator insolens Simon, 1880 from China, by monotypy.
Comments: This genus currently comprises 16 species known from India (5 spp.), China (12 spp.), Korea and Japan (one species each). Thanks to several recent regional revisions (Zhu et al., 2006; Lin & Zhu, 2016; Lin & Li, 2020; Sankaran et al., 2020), the group is relatively well studied, with most of the species (11) properly described on the basis of both sexes. Three species (P. himalayaensis Tikader & Gajbe, 1976a; P. kashmirensis Tikader & Gajbe, 1973; P. solanensis Tikader & Gajbe, 1976b) are known only from females, one only from males (P. kamurai Lin & Li, 2020), and for one species (P. indicus Simon, 1897) there are no illustrations of the copulatory organs available in the literature, albeit having been described from both sexes (World Spider Catalog, 2022). The new species described in this paper represents the first record of the genus for Pakistan and the (north)westernmost record for the whole known range of the genus.
Type material: MHNG; ♀ holotype and 1 ♀, 1 juvenile paratypes; PAKISTAN, Khyber Pakhtunkhwa Province, Swat District, above Utroor, in a forest of fir (Abies) and cedar, under the bark of a very large fallen cedar trunk, 2600 m; 13.05.1983; leg. Cl. Besuchet & I. Löbl.
Etymology: The specific epithet is a name in apposition, i.e. the ancient Greek name for the Swat River.
Diagnosis: The new species is most similar to P. pandeae and P. dazhonghua Lin & Li, 2020 by having anterior epigynal pockets (Ap). From the former species it can be distinguished by the completely fused pockets forming some kind of a narrow hood (vs. only indistinctly connected and forming a much wider structure), by glands (Gl) being as long as the oval receptacles (Re) (vs. glands much shorter than the round receptacles), and by the presence of an epigynal septum (Se) (vs. lacking). From P. dazhonghua it can be distinguished by the different shape of the anterior pockets (fused vs. separate) located at a larger distance from the copulatory openings (Fig. 1H cf. Lin & Li, 2020: fig. 2A), as well as by the considerably shorter copulatory ducts (or secondary spermathecae, sensu Lin & Li, 2020) (Fig. 1I cf. Lin & Li, 2020: fig. 2B).
Description: FEMALE (holotype). Habitus as in Fig. 1E-G. Total length 8.15. Carapace 2.65 long, 3.95 wide. Eye sizes: anterior median eye 0.17, anterior lateral eye 0.14, posterior lateral eye 0.20, posterior median eye 0.11. Carapace, sternum, labium, maxillae and chelicerae light brown. Legs of same color as carapace, without annulations. Legs I-II with numerous (especially leg I) and legs III-IV with a few erect ventral spiniform setae. Abdomen greyish dorsally, ventrally with dark patches on pale beige ground colour. Spinnerets uniformly light greyish brown. Measurements of legs: I 8.85 (3.09, 1.35, 1.94, 1.57, 0.90), II 12.17 (4.12, 1.62, 2.95, 2.32, 1.16), III 12.06 (4.11, 1.53, 2.92, 2.55, 0.95), IV 10.11 (3.43, 1.10, 2.40, 2.25, 0.93).
Epigyne as in Fig. 1H-J; plate 1.25 times wider than long, epigynal fovea shallow, more than three times wider than long, with weakly developed septum (Se, Fig. 1J); anterior pockets (Ap) fused and forming some kind of a hood; copulatory openings (Co) slit-like, transverse, located near lateral margin of fovea; copulatory ducts (Cd) large and broad, as wide as receptacles (Re); glands (Gl) long, more than four times longer than wide, slightly longer than receptacles; receptacles positioned in transverse plane, separated by about their length. MALE. Unknown.
Distribution: Known only from the type locality in the Swat District, northern Pakistan (Fig. 4).
Plator pandeae Tikader, 1969
Figs 1A-D, 2-4
Plator pandeae Tikader, 1969: 253, figs 4-7 (♀). – Hu & Li, 1987: 360, figs 30.1-4, 31.1-4 (♂♀). – Hu, 2001: 279, fig. 160.1-4 (♂♀). – Zhu et al., 2006: 42, figs 20-24 (♂♀). All Chinese references refer to the same specimens. – Sankaran et al., 2020: 137, figs 10-14, 19-24 (♂♀; including a re-examination of type material).
Material: MMUE; 1 ♂, 1 ♀, 6 juveniles; INDIA, Himachal Pradesh, Kothi Village and environs, 32°18′N, 77°11′E, 2300-2600 m, under bark of spruce tree; 29.05-8.06.1999; leg. Y.M. Marusik.
Description: See Sankaran et al. (2020). Here we provide a detailed description of the palp and the epigyne, with an emphasis on information lacking in previous publications, and comment on the structure of the female tarsal claws.
MALE. Habitus as in Fig. 1B. Palp as in Figs 2-3; tibia large, almost as long as cymbium, twice longer than wide, with long and gradually tapering tibial apophysis having a slight curvature; cymbium almost triangular in lateral view (Fig. 2B); tegulum large, as long as cymbium in retrolateral view (Fig. 2B), wider than long in prolateral view (Fig. 2C); subtegulum (St) discoid, observable only in prolateral view (Figs 2C, 3C); tegulum with spine-like apophysis (Ta) (Fig. 3A); conductor (Cn) large, membranous, with a distoprolateral extension (Fig. 3C); embolus (Em) complex, with large base, tooth-like (in ventral view) distal ridge (Et) and concave mesal extension (Me) (Fig. 3A-C); embolus proper (Ep) (i.e. part containing opening of sperm duct) ribbon-shaped, circumflexing conductor, with serrated distal margin (Fig. 3A, C).
FEMALE. Habitus as in Fig. 1A. Palp with dentate claw having four small denticles in proximal half and bent at almost right angle (Fig. 3F). Tarsal claw of leg I with single series of four denticles in proximal half (Fig. 3G); denticles relatively larger than those of palpal claw.
Epigyne as in Figs 1C-D, 3E; epigynal fovea and septum indistinct; anterior part with a widely separated pair of pockets (Ap) connected by indistinct bridge but not fused; copulatory openings (Co) slit-like; copulatory ducts (Cd) longer than wide, with short glands (Gl) close to receptacles; receptacles (Re) globular, contiguous and located posteriorly.
Distribution: This species is currently known from four localities, three in India and one in southern Tibet, China (Fig. 4).
The first author is grateful to Lionel Monod and Peter J. Schwendinger for help during his visit to the MHNG and for providing the studied material. The comments of Pradeep M. Sankaran (Sacred Heart College, Cochin, India) and of the subject editor (Peter J. Schwendinger) on an earlier draft of the manuscript are also acknowledged.