Liphistius birmanicus Thorell, 1897

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, Revue suisse de Zoologie 129 (2), pp. 375-424 : 398-402

Liphistius birmanicus Thorell, 1897

Figs 1 , 3 D-I, 13-14

Liphistius birmanicus Thorell, 1897: 162-169 (description of females). – Pocock, 1900: 156 (English summary of Thorell’s lengthy original description in Latin). – Bristowe, 1933: 1025, figs 6, 7b, 8d, 9a (comparison and illustration of characters of female). – Bristowe, 1938: 661 (misidentification; description of immature male of an unnamed Liphistius species from Moulmein). – Bristowe, 1975: 166-167 (new report based on misidentied specimen belonging to L. bristowei Platnick & Sedgwick, 1984 ). – Haupt, 1983: 280, figs

5c, 6c (illustration of vulval plate of female erroneously referred to as the holotype and later selected as the lectotype by Platnick & Sedgwich, 1984). – Platnick & Sedgwick, 1984: 8-10, figs 7-13 (designation of lectotype; description of incorrectly identified males and females belonging to L. pyinoolwin ). – Schwendinger, 1990: 331-332, figs 1-4 (illustration of copulatory organs of incorrectly identified male and female L. pyinoolwin specimens in AMNH).

Types: MCSNG; female lectotype of L. birmanicus ; Myanmar, Kayin State, Yadò (spelled Ja-dò in Fea, 1896: 457-458, fig. 149), in montibus Carin Asciuii Chebà, 1200-1300 m; 1885-1888; leg L. Fea. – MCSNG; 2 immature paralectotypes of L. birmanicus ; Myanmar, Kayin State, in montibus Carin Chebà sive Biapò, 1000-1200 m; 1885-1888; leg. L. Fea. Not examined.

Remarks: Leonardo Fea (1852-1903) collected the types of L. birmanicus between December 1887 and January 1889 ( Fea, 1897: 391). The original description states that the two juvenile specimens (the paralectotypes from Biapò, given as situated at 900 m altitude in Fea, 1896: 391) have entirely dark legs and palps (“toti nigricantes vel sordide fusci”), whereas the adult female (the lectotype from Yadò) has a carapace that is partly brick-red and partly dark (“cephalothorax praesertim in parte thoracica paullo testaceo-fuscovariatus”) as well as bicoloured legs and palps: mostly dark (“ad maximam partem… nigricantes vel sordide fusci”), with dark brick-red femora and dark brick-red annulations on patellae, tibiae and metatarsi (“patellae, tibiae et metatarsi, et etiam femora supra, vestigiis annuli vel annulorum binorum testaceo-fuscorum praedita”; Thorell, 1897: 166). This indicates that the paralectotypes from Biapò are not conspecific with the lectotype from Yadò, because small females from Yadò have bicoloured legs and palps as do the corresponding large females ( Fig. 3G cf. Fig. 3 E-F, H-I). It is quite likely that the paralectotypes belong to L. ferox sp. nov., because Biapò is much closer to Thandaung Gyi than to Yadò ( Fea, 1896: pl. 3), and because L. ferox sp. nov. has an exceptionally large vertical distribution (from 140 m to 1400 m). It presumably also has a correspondingly large geographical range.

New material: MHNG, BRCM (sample MT-14/33); 6 males (matured 24.IX.2014, 30.X.2014, 15.XI.2014, 27.I.2016, 28.II.2016, 9.XI.2017) and 10 females; Myanmar, Kayin State, farmland and rice fields in the southern part of the Yado (= Yadò) Valley, near the southernmost village called “Preisciò” in Fea (1896: 458, pl. 3), 19°19’50”N, 96°48’29”E, 1100 m; 18.-19. VI.2014; leg. P. Schwendinger & S. Huber. – MHNG (sample MT-14/35); 1 female; Myanmar, Shan State, roadside about 3 km NE of the northern end of the Yado Valley, 19°23’20”N, 96°49’29”E, 1130 m; 19.VI.2014; leg. P. Schwendinger.

Diagnosis: Quite large spiders (CL in males 7.79-9.50, in the largest female 14.73, CW in males 7.29-9.45, in the largest female 13.27) with parts of legs, palps and carapace (especially pars cephalica) of females and late instar juvenile males yellow or orange-coloured ( Fig. 3 E-I; Xu et al., 2021: fig. 2I). Palp of male similar to that of much smaller L. pinlaung male, both possessing a distad-directed proventral contrategular process ( Fig. 13D, F and Fig. 15C ). Different from L. pinlaung by a more oval palpal organ in distal view ( Fig. 13A cf. Fig. 15A ), a wider and shorter pigmented area at base of membranous embolus part ( Fig. 13D cf. Fig. 15C ) and a widely arched retrolateral paracymbium side lacking a proximal heel ( Fig. 13H cf. Fig. 15G ). Vulval plate distinguished from that of uniformly dark brown L. pinlaung female by anterior lobes of poreplate closer to each other and posterior stalk more angular in shape ( Fig. 14 cf. Fig. 16 ).

Additions to description: Males mostly with uniformly dark brown sclerites ( Fig. 3D ; Xu et al., 2021: fig. 2J), apart from an orange-coloured area in posterior portion of cephalic carapace part in some males (see Variation), and with weak scopulae on tarsi I-II, slightly denser ones on tarsi III-IV, covering only distal 1/2 of tarsus I, distal 2/3 of tarsus II, distal 3/4 of tarsus III and distal 4/5 of tarsus IV in most males (see also Variation). Male palp with moderately deep tibial apophysis (depth/ length ratio ~ 1.8), relatively small and triangular in ventral view, only slightly set back from distal margin of tibia (illustrated as distinctly set back in Xu et al., 2021: fig. 8A), carrying four long pointed apical megaspines; distal margin of palpal tarsus widely but shallowly invaginated, with a small knob-shaped process on distodorsal corner ( Fig. 13C ); paracymbium short, somewhat globular in ventral view, its retrolateral surface widely and evenly arched, without a proximal heel ( Fig. 13H ); cumulus slightly elevated, carrying a dense group of several long strong bristles close to each other and arranged in two rows ( Fig. 13H ); subtegulum without apophysis ( Fig. 13E ); tegulum large, its distal margin not elevated, its proximal edge widely arched, finely dentate, bent and overhanging membranous area below it ( Fig. 13 E-G); contrategulum with proventral process conical and inclined distad (almost parallel to axis of embolus proper), its apex narrowly rounded ( Fig. 13A , D-F; Xu et al., 2021: fig. 8D-F); a few oblique wrinkles on dorsal surface ( Fig. 13D ) and a pronounced proximal ledge on retrodorsal side ( Fig. 13A, D, G ); distal edge of contrategulum moderately wide, with a few ridges and a narrowly rounded dorsal apex ( Fig. 13 A-B), prolateral part of edge elevated and developed as a distinct keel ( Fig. 13D ); paraembolic plate short, about as long as retroventral edge of embolus complex and separated from it by a shallow invagination ( Fig. 13 E-F); embolus proper with sclerotised part strengthened by 5-6 longitudinal ribs reaching apex and carrying denticles distally, narrowly divided from distinctly shorter membranous embolus part; short area at base of membranous part strongly pigmented, with numerous longitudinal wrinkles, its distal margin wide and slightly oblique ( Fig. 13D ). Females with few to several hairs on lateral folds of vulval plate; poreplate as long as wide ( Fig. 14 NO), or wider than long ( Fig. 14 A-M), posteriorly wider than anteriorly, with a pair of rather indistinct ( Fig. 14L ) to very wide, rounded lobes ( Fig. 14 N-O) on anterior margin, and with a small pair of anterolateral processes; CDO fairly small, round, quadrangular or triangular ( Fig. 14A, D, G, J, N ); receptacular cluster racemose, slightly to distinctly longer than wide, not reaching anterior margin of poreplate ( Fig. 14 B-C, E-F, H-I, K-M, O; Xu et al., 2021: figs 9-10); posterior stalk narrower than poreplate, axe-blade-shaped, with posterior margin widely arched ( Fig. 14 G-I, L) or trapezoidal, in the latter case posterior margin straight and narrower than median part of posterior stalk ( Fig. 14 A-F, J-K, M-O); transition from poreplate to posterior stalk usually distinctly constricted (see also Variation).

Variation: For carapace measurements and prefoveal setae counts see Table 1 . In all specimens the AME are distinctly developed. The number of setae anterior to the fovea ranges 11-25 in males and it is over 40 (continuous with other setae on pars cephalica of carapace) in all females. Three males have a distinct orange-coloured area in the posterior portion of the pars cephalica; in one male this area is only indistinct; in the remaining two males it is not visible. In the female from the Shan State the carapace has a larger orange-coloured area than in females from Yado, with the W-shaped dark marking behind its eye mound only continuous in the middle, the lateral parts developed as series of dark spots. In males the extent of the tarsal scopulae is slightly variable: I - 1/2-2/3, II - 2/3-3/4, III - 3/4-4/5, IV - 4/5. Variation in details of the male palp is given in Fig. 13 . In one of the males examined the tibial apophysis is slightly further set back from the distal margin of the palpal tibia than in other males, but not as far as illustrated in Xu et al., 2021: fig. 8A. Variation in the shape of the vulval plate is considerable (see Fig. 14 ; Xu et al., 2021: figs 9-10). The anterior margin of the poreplate is indistinctly ( Fig. 14 J-K) to deeply invaginated ( Fig. 14 N-O); the poreplate is usually clearly wider than long ( Fig. 14 AM), in one female as long as wide ( Fig. 14 N-O); the anterior lobes of the poreplate are indistinct ( Fig. 14 JK) to very distinct ( Fig. 14 N-O); the CDO is small ( Fig. 14A ) to very small ( Fig. 14N ), round in most females, developed as a longitudinal slit or triangle in two specimens ( Fig. 14D, G ); the pores on the dorsal side of the poreplate are quite large ( Fig. 14A, J ) to small ( Fig. 14N ); the lateral margins of the poreplate vary from widely arched ( Fig. 14 J-K) to almost straight ►

( Fig. 14 N-O); the posterior stalk is constricted at the base, trapezoidal, posteriorly narrower than medially in most females, axe-blade-shaped in two specimens ( Fig. 14G, L ), or widely connected to the poreplate without a constriction in another specimen ( Fig. 14M , presumably deformed). It should be noted that almost all vulval plates had more or less distinct dark soiling, especially along the posterior margins of the poreplate (removed by forceps in the illustrated vulvae). These are remnants of old cuticle, and the older the spider, the denser and thicker these remaining fragments of old cuticle are. In one of the large females this presumably caused deformation at the posterior poreplate margin and at the base of the posterior stalk ( Fig. 14M ; see also Xu et al., 2021: fig. 9F, I). Tiny fragments of old cuticle are also visible inside the lateral folds of the vulval plate in some specimens (e.g. Fig. 14B , I-M). The anterolateral processes on the ventral side of the poreplate are always present, but not always very pronounced ( Fig. 14B ).

Relationships: Males of L. birmanicus and L. pinlaung share a strongly distad-directed proventral process of the contrategulum, which is unique within the genus and indicates a close phylogenetic relationship (in addition to geographical proximity) between these two species despite pronounced differences in body size and colouration. Judging from the body colouration of females and juveniles and from vulval plate morphology it is quite likely that L. birmanicus is even more closely related to L. hpruso than to L. pinlaung . However, as long as the male of L. hpruso remains unknown or until molecular data of these three species are available for comparison, the relationship between these species cannot be confirmed. For a morphological distinction between L. birmanicus and L. hpruso see Taxonomic remarks under the latter species.

Distribution: Liphistius birmanicus is known from the mountainous area where the Kayin State, the Kayah State and the Shan State meet ( Fig. 1 ). The report of a damaged immature L. birmanicus male from Moulmein (= Mawlawmyine) by Gravely (1915: 260; see also Bristowe, 1938: 661) is most likely incorrect. Liphistius males and females collected at two localities near Mawlawmyine belong to the bristowei -group.

Biology: The specimens examined were collected from earth banks on the sides of rice fields, vegetable fields and ditches. Most burrows were simple and unbranched, closed by a single trapdoor; one penultimate male had two doors. The largest trapdoor in females was 3.5 cm long and 5.1 cm wide, those of penultimate males 2.0- 2.4 cm long and 3.2-3.6 cm wide. Burrow entrances had 6-8 relatively thick and short signal lines attached, the longest measuring 6 cm.

The first three males matured in captivity between early September and mid-November, only a few months after being captured. Two maturations of males, in January and February, occurred about 1.5 years after capture and presumably do not correspond with such events in nature. No egg cases were found in the field in late June; they are presumably constructed in December (as in conspecific species in northern Thailand). Most large females moulted twice per year.

One of the males examined (matured 30.X.2014) had parasitic mites ( Ljunghia sp. ) sitting on its carapace (especially in the fovea), on the membranous cuticle behind the carapace, on opisthosomal tergites I-II (where mite exuviae were attached) and on the labium and sternum. As usual, the mites left numerous bite marks on the carapace, but not on the chelicerae (or on any other body parts).

Figures

Fig. 1. Localities of species in the Liphistius birmanicus-group in northern Thailand, eastern Myanmar and southern China. Blue lines indicate major rivers, black lines national borders, grey lines major roads.

Fig. 3. Habitus of some species of the Liphistius birmanicus-group. (A) Liphistius ferox sp. nov., male paratype (matured 1.IX.2014) from Pathi Village. (B) Same species, female paratype from Thandaung Gyi. (C) Liphistius pinlaung, female from near Tong Htiwaw Temple. (D) Liphistius birmanicus from Yado, male (matured 20.IX.2017). (E) Same species, large female n°1. (F, H) Same species, large female n°2. (G) Same species, small female. (I) Same species, large female n°3. Not to scale.

Fig. 13. Liphistius birmanicus, left palps of two males from the type locality; male matured 27.I.2016 (A-B), male matured 15.XI.2014 (C-H). (A) Palpal organ, distal view (dorsal side up). (B) Dorsal part of contrategulum, distal and slightly prolateral view. (C) Distal part of tarsus, prodorsal view; knob-shaped process on distodorsal corner indicated by short arrow. (D) Palpal organ and distal margin of tarsus, prolateral view. (E) Same, ventral view; bent proximal edge of tegulum indicated by long arrow. (F) Distal part of palpal organ, retroventral and slightly proximal view. (G) Palpal organ, retrolateral view. (H) Proximal part of tarsus, ventral view. Scale line 1.0 mm.Abbreviation: cp - proventral contrategular process.

Fig. 15. Liphistius pinlaung, left palps of two males: matured 23.XI.2014 (A-B), matured 4.VII.2015 (C-G). (A) Palpal organ, distal view (dorsal side up). (B) Dorsal part of contrategulum and embolus proper, distal and slightly prolateral view. (C) Palpal organ and distal margin of tarsus, prolateral view. (D) Palpal organ, ventral view; bent proximal edge of tegulum indicated by arrow. (E) Distal part of palpal organ, retroventral view. (F) Tegulum, retrolateral view. (G) Proximal part of tarsus, ventral view.All to same scale; scale line 1.0 mm. Abbreviation: cp - proventral process of contrategulum.

Fig. 14. Liphistius birmanicus, vulval plates (all taken from exuviae) of ten females from the type locality (A-M) and of one female from the Shan State (N-O); dorsal view [A, D (with uterus externus attached), G, J, N], ventral view (B-C, E-F, H-I, K-M, O). (A-B) Moult of 6.II.2021. (C) Moult of 27.XII.2020. (D) Moult of 20.XI.2021. (E) Moult of 19.II.2021 (same specimen as D). (F) Moult of 21.II.2021. (G-H) Moult of 25.XII.2020. (I) Moult of 14.V.2021. (J-K) Moult of 20.III.2021. (L) Moult of 26.X.2017. (M) Moult of 24.VIII.2017. (N-O) Moult of 2.IV.2018. Arrows indicating paired lateral pockets of membranous uterus externus. Scale lines 1.0 mm.

Fig. 16. Liphistius pinlaung (A-J) and Liphistius sp. (specimen from Kalaw; K-L), vulval plates of seven females (all taken from exuviae), dorsal view (A, D, G, I, K) and ventral view (B-C, E-F, H, J, L). (A-B) Moult of 10.II.2019. (C) Moult of 7.XII.2018. (D-E) Moult of 10.IV.2021. (F) Moult of 21.X.2018. (G-H) Moult of 16.V.2020. (I-J) Moult of 8.III.2020. (K-L) Moult of 15.VIII.2017. Scale lines 1.0 mm.