Liphistius pinlaung Aung, Xu, Lwin, Sang, Yu, Liu, Liu & Li 2019
Creators: name: Schwendinger, Peter J.
name: Huber, Siegfried
name: Lehmann-Graber, Christina
name: Ono, Hirotsugu
name: Aung, Mu Mu
name: Hongpadharakiree, Komsan
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Liphistiidae
Liphistius
Liphistius pinlaung

description: Liphistius pinlaung Aung, Xu, Lwin, Sang, Yu, Liu, Liu & Li, 2019
Figs 1, 3C, 15, 16 A-J
Liphistius pinlaung Aung, Xu, Lwin, Sang, Yu, Liu, Liu & Li, 2019: 34-37, figs 4-5 (description of males and females).
Types: CBEE; male holotype (XUX-2018-164), 1 male and 5 female paratypes (XUX-2018-162, 167, 169, 169A, 169B, 169J); Myanmar, Shan State, Pinlaung Township, about 14 km to Pinlaung from Pekon, 20.02°N, 96.79°E, 1410 m; 19.VII. 2018; leg. D. Li, F.X. Liu, X. Xu and L. Yu.
New material: MHNG, BRCM (sample MT-14/31); 10 males (matured 20.VI., 21.VI., 28.VI., 20.VIII., 17.IX., 23.IX.2014, 23.XI., 2x end of XII.2014, 4.VII.2015) and 10 females; Myanmar, Shan State, 1.5 km W of Pinlaung, near Wingabar Taung and Tong Htiwaw (= Taung Hti Bwar) Temple, 20°04’29”N, 96°46’13”E, 1470 m; 16.VI.2014; leg. P. Schwendinger & S. Huber.
Diagnosis: Medium-sized species with uniformly dark body in both sexes. Copulatory organs quite similar to those of L. birmanicus. Palpal organ distinguished by having a fairly circular outline in distal view (Fig. 15A; in L. birmanicus oval and relatively wider, Fig. 13A) and a relatively longer and narrower pigmented area with a more steeply inclined distal margin at base of membranous embolus part (Fig. 15C; in L. birmanicus much wider, its distal margin horizontal or only slightly inclined, Fig. 13D). Vulval plates usually, but not in all cases, with a relatively wider poreplate than in L. birmanicus and with an axe-blade-shaped or widely elliptical posterior stalk with a widely arched posterior margin (Fig. 16; posterior stalk angular, mostly with a straight posterior margin in L. birmanicus, Fig. 14).
Additions to description of male: Tarsal scopulae: I - thin, covering 3/4 of ventral side, distinct in distal half, more or less distinct in proximal half; II - thin but slightly denser than on tarsus I, covering distal 5/6 of ventral side; III-IV - denser than on tarsi I-II, covering 5/6 of ventral side. Male palps with tibial apophysis quite distinctly set back from distal margin of tibia (more so than in the L. birmanicus males examined; but see Xu et al., 2021: fig. 8A-B), triangular in ventral view, depth/length ratio ~ 1.9 (see Aung et al., 2019: fig. 4D-E); paracymbium quite short, its distal surface indistinctly conical, its retrolateral surface flat, with a moderately developed, widely rounded retrolateralproximal heel (Fig. 15G); very strong bristles on low cumulus overlapping strong bristles on ventral side of palpal tarsus (Fig. 15G); contrategulum with quite large, distad-directed proventral process (Fig. 15A, C-E; very similar to that of L. birmanicus, Fig. 13A, D-F), with a pronounced proximal ledge on retrodorsal side (Fig. 15A), and with a moderately wide distal edge with a few weak ridges and a narrowly rounded dorsal apex (Fig. 15 A-B); tegulum large, with finely dentate and bent proximal edge (Fig. 15D, F), distal margin not elevated [in some specimens a fairly long ridge is present just below the distal margin (in addition to a long median ridge) which can be misinterpreted as an elevated edge, Fig. 15F]; para-embolic plate short, about as long as retroventral edge of embolus complex and separated from it by a shallow invagination (Fig. 15D); embolus proper narrowly divided, its sclerotised part strengthened by 4-5 longitudinal ribs reaching apex and carrying denticles distally; area at base of membranous embolus part quite long and narrow, distinctly pigmented, with numerous longitudinal wrinkles, its distal margin widely truncate and steeply inclined (this area is much wider in L. birmanicus, its distal margin is not or only slightly inclined, Fig. 13D).
Taxonomic remarks: As can be seen from the relatively light body colouration and from the partly collapsed paracymbium, the male holotype was obviously killed and preserved very soon after its final moult. Metatarsus and tarsus of both its legs IV were very pale when still alive, and additionally deformed (due to a weak sclerotisation of the new cuticle) in the preserved specimen (Aung et al., 2019: figs 2D, 4B). These leg articles obviously got stuck in the exuvia during the final moult, and were not able to become fully pigmented and sclerotised before the spider was killed. Therefore the light-coloured left metatarsus and tarsus IV of the holotype are an artefact caused by a moulting accident, and they are not a diagnostic character of the species as incorrectly stated by Yu et al. (2021: 37, incorrectly spelled “ L. pinglaung ”). The fact that the proventral process of the contrategulum is distad-directed, which is characteristic for L. pinlaung as well as L. birmanicus, is not mentioned in the original description or visible in the corresponding illustrations (Aung et al., 2019: 36, fig. 4).
Variation: For carapace measurements and prefoveal setae counts see Table 1. In all specimens the AME are distinctly developed. In all males examined the extent of the tarsal scopulae is essentially the same, but in some specimens the proximal borders of the scopulae are less distinctly outlined than in others. Variation in details of the male palp is given in Fig. 15. The number of very strong bristles on the cumulus ranges 4-7: in most males examined (apart from one) they overlap strong bristles on the ventral side of the palpal tarsus (Fig. 15G). In five males examined there is a more or less distinct ridge below the distal margin of the tegulum of both palps (and in one male on only one palp; Fig. 15F), which can be misinterpreted as an elevated distal edge. A real elevated distal tegular edge is present in L. platnicki sp. nov. (Fig. 23 I-M), in L. nabang (Yu et al., 2021: fig. 3A-B, D-E) and in males of other species groups. Small females have distinctly annulated legs, in large females the annulations have become indistinct. Variation in the shape of the vulval plate is considerable, especially in shape and size of the anterior lobes and the distance between them, and in the shape of the posterior stalk (Fig. 16 A-J; Aung et al., 2019: fig. 5). The posterior margin of the posterior stalk is mostly straight in all three female paratypes illustrated in Aung et al. (2019: fig. 5), much like in females of L. birmanicus (Fig. 14), whereas in the females examined by us it ranges from straight (Fig. 16 D-E), to widely rounded (Fig. 16 I-J) and very widely V-shaped (Fig. 16C). The poreplate of the smallest female examined has an exceptionally small receptacular cluster and relatively large pores (some much larger than the CDO; Fig. 16 I-J). This appears to be a general feature of young (immature?) females rather than a case of individual variation in this species. The same female also has a single hair between the poreplate and the posterior stalk, which is unusual for species of the birmanicus -group (but see vulval plates of some species in Peninsular Malaysia, Schwendinger, 2017: figs 7, 9, 13, 14I-J).
Relationships: Despite pronounced differences in body colouration of females and juveniles, similarities in male (especially in the distad-directed proventral contrategular process) and female copulatory organs indicate a close relationship between L. pinlaung and L. birmanicus. Liphistius hpruso may also be very closely related, but that needs to be confirmed by the discovery of its male or by genetic analysis.
Distribution: Liphistius pinlaung is known from two localities near Pinlaung Village in the western part of the Shan State (Fig. 1).
Biology: The specimens examined were collected from earth banks on the sides of a road and of rice fields. All burrows were simple and unbranched, closed by a single trapdoor. The largest trapdoor in females was 2.0 cm long and 2.5 cm wide, those of penultimate males 1.2- 1.7 cm long and 1.7-2.4 cm wide. Burrow entrances had 6-8 signal lines attached, the longest measuring 5 cm. The first three males matured within two weeks after being captured, a fourth one over three months later; maturation in November of the following year and of July of the year after that are presumably due to conditions in captivity. Most females moulted twice per year, in June to July and again in October to December; old females moulted only once per year.
description: Published as part of Schwendinger, Peter J., Huber, Siegfried, Lehmann-Graber, Christina, Ono, Hirotsugu, Aung, Mu Mu & Hongpadharakiree, Komsan, 2022, A taxonomic revision of the Liphistius birmanicus-group (Araneae: Liphistiidae) with the description of five new species, pp. 375-424 in Revue suisse de Zoologie 129 (2) on pages 402-404, DOI: 10.35929/RSZ.0083, http://zenodo.org/record/7761487