Liphistius ferox Schwendinger & Huber

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 : 392-398

Liphistius ferox Schwendinger & Huber , sp. nov.

Figs 1 , 3 A-B, 10-12

Holotype: MHNG-ARTO-0028317 (sample MT-14/10); male (matured 2.X.2014); Myanmar, Kayin State, Thandaung Lay (19°01’15”N, 96°35’00”E), 140 m; 16.VII.2014; leg. P.J. Schwendinger & S. Huber.

Paratypes: MHNG-ARTO-0028318 and MHNGARTO-0028319 (sample MT-14/10); 1 male (matured 1.IX.2014) and 1 female (allotype, MHNGARTO-0028319); collected together with the holotype. – BRCM, MHNG-ARTO-0028321 and MHNG-ARTO-0028322; 2 males (matured 7.X.2014, 18.IX.2016) and 1 female (sample MT-14/04); Myanmar, Kayin State, along road from Thandaung Lay to Thandaung Gyi, 850 m (19°01’54”N, 96°38’29”E); 12./14./16.VII.2014; leg. P.J. Schwendinger & S. Huber. – MHNG-ARTO-0028323 to MHNG-ARTO-0028333, BRCM (samples MT-14/07); 1 male (matured 10.IX.2014) and 11 females (samples MT-14/05 and MT-14/06); along same road, 1150 m (19°04’15”N, 96°40’37”E); 12./14./16.VII.2014; leg. P.J. Schwendinger & S. Huber. – MHNG-ARTO-0028335 to MHNG-ARTO-0028340 (samples O-234A and MT-14/07); 1 male (matured IV.2019) and 5 females; Myanmar, Kayin State, Mt Naw Bubaw (19°04’39”N, 96°41’12”E), 1350-1410 m; 12./14.VII.2014; leg. P.J. Schwendinger & S. Huber.

Other material: MHNG (sample MT-14/07); 3 juveniles; Myanmar, Kayin State, Mt Naw Bubaw (19°04’39”N, 96°41’12”E), 1350-1410 m; 12./14. VII.2014; leg. P.J. Schwendinger & S. Huber. – BRCM; 1 female; Myanmar, Kayin State, on roadside about 7 km E from border between Bago Region and Kayin State, Thaundaung Gyi Township (19°01’56.3”N, 96°38’39.2”E), 850 m; 6.VIII.2018; leg. H. Ono. – BRCM; 1 female; Myanmar, Kayin State, 21 miles E of Taungoo, Thaundaung Gyi Township, near Taw Pya Gyi Village (19°02’35.5”N, 96°39’38.1”E), 940 m; 6.VIII.2018; leg. H. Ono.

Etymology: The Latin adjective “ferox” (= wild, ferocious) refers to the exceptionally aggressive behaviour of these spiders.

Diagnosis: Distinguished from all other species of the birmanicus -group by the combination of very large size and uniformly dark body colouration in both sexes. Genital morphology similar to that of L. tung ◄ sp. nov., i.e. both species possessing a long paraembolic plate in males ( Fig. 10 A-D and Fig. 8A , H-I; short in other species of the birmanicus -group) and lacking anterolateral processes on the ventral side of the poreplate in females ( Figs 11-12 and Fig. 9 ). Different from L. tung sp. nov. by much larger body size (CL in males 11.47-12.67, CW 10.45-11.47 versus 6.30- 6.70 and 5.70-6.26 in L. tung sp. nov.); sclerotised embolus part with only 2 longitudinal ribs reaching apex, one of them with a triangular distal protrusion pointing retrodorsad ( Fig. 10 E-H); retrolateral side of sperm duct opening angular in distal view ( Fig. 10H ; in L. tung sp. nov. with 4-5 normal ribs and concave retrolateral side of sperm duct opening, Fig. 8 C-D, F-I); proventral process of contrategulum relatively larger than in L. tung sp. nov. ( Fig. 10H cf. Fig. 8 C-D); tibial apophysis only slightly set back from distal margin of tibia ( Fig. 10J ; much further set back in L. tung sp. nov., Fig. 8B ). Females different from those of L. tung sp. nov. by anterior lobes of poreplate folded ventrad and more widely separated from each other ( Figs 11-12 cf. Fig. 9 ).

Description of male (holotype): Colour in alcohol (much darker in life, as in Fig. 3A ): Mostly uniformly brown, ventral side of body slightly lighter than dorsal side; prolateral part of palpal coxae, proximal part of chelicerae and membranous cuticle of opisthosoma light brown; all opisthosomal tergites uniformly dark brown; legs and palps without annulations; palpal tarsus and sclerites of palpal organ dark brown; eye mound very dark.

Setae on carapace: Few short, blunt-tipped setae on coxal elevations and on lateral margin of carapace; strongest setae on posterior margin, longest setae on and behind eye mound; no setae anterior to fovea.

Cheliceral teeth: 12 small teeth of different sizes on promargin of each cheliceral groove.

Scopula: Distally divided by a short glabrous longitudinal stripe and proximally with a median row of stiff bristles on all tarsi; distinct but weak in distal 3/4 of ventral side of leg tarsus I; equally weak and covering distal 4/5 of tarsus II; slightly denser and more clearly outlined, covering 5/6 of tarsi III-IV.

Tarsal claws: Paired claws with 4-5 teeth on tarsi I-III, 3-5 teeth on tarsus IV; unpaired claw of tarsus I with 1 denticle, of tarsi II-III with 1-2 denticles, of tarsus IV bare.

Palp: Tibial apophysis of moderate size, widely triangular in ventral view, slightly set back from distal margin of tibia ( Fig. 10J ), carrying 5 apical megaspines: ventral one rather weak, longer than the others and ending in a filiform tip, following 3 megaspines shorter and stronger, dorsalmost megaspine shortest and weakest; 3 ventral megaspines situated on a common base, 2 dorsal ones each on a separate base ( Fig. 10K ; see also Variation). Distal margin of tarsus slightly invaginated ( Fig. 10F ). Paracymbium quite short, somewhat quadrangular, longer than wide in ventral view, moderately deep, its distal side only indistinctly conical, no retrolateralproximal heel ( Fig. 10A ); cumulus developed as a slightly elevated and quite long, low mound carrying a densely packed group of 9 long strong bristles ( Fig. 10A ). Subtegulum with indistinct but recognizable apophysis ( Fig. 10A, G ). Tegulum wide, with slightly bent, adpressed, moderately serrate proximal edge ( Fig. 10B, G ); distal margin not elevated, overhung by unpigmented retroventral margin of embolus complex; with a short subdistal ridge (not to be misinterpreted as an elevated distal tegular edge) and two longer more proximal ridges ( Fig. 10G ). Pigmented bridge between tegulum and contrategulum on retrodorsal side of palpal organ well developed ( Fig. 10 G-H). Contrategulum with quite large (in comparison with other species of the same group), conical proventral process ending in a rounded apex in distal view ( Fig. 10H ); a few wrinkles on dorsal surface and a well-developed proximal ledge on retrodorsal side ( Fig. 10F , H-I); distal edge of contrategulum widely arched and carrying pronounced ridges below narrowly rounded dorsal apex ( Fig. 10 H-I). Para-embolic plate large, toungue-shaped, inclinded prodorsad, its widely rounded apex with a small indentation ( Fig. 10 A-B; see also Variation). Retroventral edge of embolus complex elevated into a short, widely arched keel ( Fig. 10 AB). Embolus proper with sclerotised part strengthened by only 2 longitudinal ribs reaching apex and carrying tiny denticles distally, ventral rib with a triangular distal protrusion pointing prodorsad ( Fig. 10 E-H); retrolateral side of sperm duct opening (i.e. inner side of sclerotised embolus part) angular in distal view ( Fig. 10H ; concave in other congeners, e.g. Fig. 15A ); membranous part of embolus proper distinctly shorter than sclerotised part, both narrowly divided; at base of membranous embolus part a fairly long and strongly pigmented area with numerous longitudinal wrinkles, its distal margin strongly oblique; embolic folds short and indistinct ( Fig. 10 E-F).

Measurements: Total length 28.97; CL 12.59, CW 11.81; opisthosoma 13.28 long, 8.97 wide; eye mound 1.37 long, 1.80 wide; palpal coxa 3.62 long, 2.50 wide; labium 1.12 long, 2.24 wide; sternum 6.03 long, 3.45 wide (1.72 on ventral surface); palp 21.90 long (6.21 + 4.05 + 7.76 + 3.88); leg I 35.09 long (9.66 + 5.17 + 7.41 + 8.88 + 3.97); leg II 36.72 long (9.83 + 5.34 + 7.67 + 9.74 + 4.14); leg III 39.57 long (9.83 + 5.43 +7.93 + 11.55 + 4.83); leg IV 48.45 long (12.07 + 5.69 + 9.57 + 15.09 + 6.03).

Description of female (allotype): Colour in alcohol (distinctly darker in life, as in Fig. 3B ): Mostly dark brown. Eye mound and anterior margin of carapace very dark. Chelicerae dark brown distally, orange-coloured proximally. Carapace without pattern; legs and palps without annulation. Tergites and membranous cuticle of opisthosoma almost equally dark greyish brown. Ventral side of palpal coxae, distal part of labium, ventral plates of opisthosomal segments II-III, and spinnerets orangecoloured. Sternum greyish orange-coloured.

Setae on carapace: Mostly as in male, but setae on posterior margin longer and thinner; 3+4 setae (some very small) in two parallel rows anterior to fovea.

Cheliceral teeth: 14 strong teeth on promargin of right cheliceral groove, 15 on left groove.

Claws: Palpal claws with 2 and 3 worn denticles. Paired tarsal claws of legs I-II with 3 teeth, of leg II with 4 teeth, of legs III-IV with 3-4 teeth; unpaired claw of leg I with 1 denticle, of leg II with 2, of leg III with 1-2 denticles, of leg IV with 0-1 denticle. All tarsi without scopula.

Vulva ( Fig. 11 M-N): Uterus externus with a pair of quite large lateral pockets on dorsal side (see Fig. 11N ; see also Figs 11 I-J, P, 12D, F for other females). Vulval plate slightly wider than long; its lateral folds well-developed and carrying several hairs. Anterior margin of poreplate thick, with a pair of narrow anterior lobes bent ventrad and separated by a shallow, mostly horizontal invagination (but see Variation); no anterolateral processes; posterior margins of poreplate not bulged; CDO small, situated in centre of poreplate; receptacular cluster racemose, distinctly longer than wide, not reaching anterior margin of poreplate. Posterior stalk large and widely oval, narrower than poreplate.

Measurements: Total length 35.34; CL 15.26, CW 13.97; opisthosoma 15.34 long, 13.28 wide; eye mound 1.75 long, 2.13 wide; palpal coxa 5.34 long, 3.79 wide; labium 1.81 long, 3.45 wide; sternum 7.93 long, 4.31 wide (2.59 on ventral surface); palp 25.95 long (8.19 + 5.00 + 6.55 + 6.21); leg I 31.46 long (9.83 + 6.03 + 6.38 + 6.81 + 2.41); leg II 32.93 long (10.17 + 6.21 + 6.38 + 7.41 + 2.76); leg III 35.94 long (10.34 + 6.55 + 6.72 + 8.97 + 3.36); leg IV 47.94 long (13.10 + 6.90 + 9.31 + 13.97 + 4.66).

Variation: For carapace measurements and prefoveal setae counts see Table 1 . All spiders examined have well-developed AME. Large and small specimens of both sexes lack annulations on legs and palps. In all males examined the extent and density of the scopulae are the same; all have a very similar shape of their proventral contrategular process, all have only two longitudinal ribs reaching the apex of the sclerotised embolus part (one of the ribs with a triangular distal protrusion), and all have an angular inner side of the sclerotised embolus part. The ventral part of the tibial apophysis carries a group of 3-4 rather long apical megaspines on a common base, the dorsal part a group of 1-2 rather short megaspines on a separate base; both bases are separated by a distinct invagination ( Fig. 10 KM). The indistinctly elevated cumulus carries 6-9 long and very strong bristles (some of them almost as thick as the megaspines on the tibial apophysis). All but one male (matured 1.IX.2014) have a more or less distinctly developed, short subdistal ridge on the tegulum that can be misinterpreted as an elevated distal margin ( Fig. 10G ). There is some variation in the number of ridges on the surface of the tegulum and in their lengths. The distal margin of the large para-embolic plate is widely rounded or has one or more angles in most specimens ( Fig. 10 C-D); it is slightly invaginated on the left palp of the holotype ( Fig. 10 A-B). The pigmented area at the base of the membranous embolus part has a distal margin that varies between straight, slightly invaginated, slightly inclined and asymmetrically angular. Variation in details of the male palp is illustrated in Fig. 10 . Variation in the shape of the vulval plate is considerable and shown in Figs 11-12 . The anterior lobes of the poreplate (which are mostly quite small) are completely bent ventrad, towards the receptular cluster, in the allotype ( Fig. 11M ), less distinctly so in other females examined ( Figs 11B, D, F, H, L, O , 12 B-C, E), and the invagination between these lobes is more or less straight and horizontal, but always wide and shallow; all females lack anterolateral processes on the poreplate; the posterior margins of the poreplate are mostly indistinct, bulging only in one female and there probably deformed on one side ( Fig. 11F ), therefore not typical for the species. The receptacular cluster is much longer than wide in most females, in one specimen even reaching the anterior margin of poreplate ( Fig. 11H ); only in one of the females examined is the receptacular cluster only slightly longer than wide ( Fig. 12C ). The posterior stalk usually has a short anterior constriction, except for one female which obviously has deformed posterior poreplate margins ( Fig. 11 E-F; the same appears to be the case, but only on one side and therefore probably also representing a deformation or an excessive sclerotisation, in a second female, Fig. 11 G-H). The shape of the posterior stalk varies from widely oval (e.g. Fig. 11M ) to narrowly (e.g. Fig. 12C ) or widely axeblade-shaped (e.g. Fig. 11O ). The lateral folds of the vulval plate carry few to many hairs.

Relationships: The new species possesses unique and autapomorphic characters on the sclerotised part of its embolus proper, i.e. only two longitudinal ribs, one of them with a triangular distal protrusion ( Fig. 10 E-H); the retrolateral surface of sperm duct opening compressed and angular in distal view ( Fig. 10H ). It clearly is not very closely related to L. birmanicus , despite close geographical proximity and similar body size. Similarities in the morphology of male and female copulatory organs (especially the presence of a large para-embolic plate and the absence of anterolateral processes on the poreplate) indicate a much closer relationship between L. ferox sp. nov. and L. tung sp. nov. than between L. ferox sp. nov. and L. birmanicus . However, the geographical separation of L. ferox sp. nov. and L. tung sp. nov. by about 400 km severely challenges a possible sister relationship between these two species.

Distribution: The type specimens were collected along the road from Thandaung Lay (also called Pathi

Village) in the lowlands at 140 m altitude, past a station at 850 m, to Thandaung Gyi Village at about 1150 m, and further up to below the summit of Mount Naw Bubaw at 1350-1410 m ( Fig. 1 ). This is the largest known altitudinal range for any Liphistius species. The paralectotypes of L. birmanicus from the Biapo Mountains near Leiktho (spelled “Leito” in Fea, 1896), about 15 km north of Thandaung Gyi and Naw Bubaw, presumably also belong to L. ferox sp. nov. (see Remarks under L. birmanicus ).

Biology: The specimens examined were collected from earth banks on both sides of a road running through secondary forest and evergreen hill forest. All burrows were simple and unbranched, closed by a single trapdoor. The largest trapdoor in females was 4.3 cm long and 6.5 cm wide, those of penultimate males 2.8-3.5 cm long and 3.9-5.0 cm wide. Most burrow entrances had 6-8 signal lines attached, the longest measuring 8 cm, a single burrow was equipped with nine signal lines.

Males matured in captivity between early September and early October, only a few months after being captured. The maturation date in June 2019, after almost five years of captive rearing, is not likely to correspond to conditions in nature. No egg cases were found in mid-July; they are presumably constructed in December (as in conspecific species in northern Thailand). Large females usually moulted once per year, between July and February; smaller females moulted for a second time between March and May. Two spiders, a female from Thandaung Gyi at 1150 m and a juvenile male from Naw Bubaw at 1400 m, carried ectoparasitic mites of the genus Ljunghia (see Halliday & JuvaraBals, 2016) on them. The mites left bite marks on the carapace and chelicerae (in the proximal and distal portions) as observed in other Liphistius spp. , and additionally also on the soft and flexible membranes between coxae, trochanters and femora of the palps and of the first pair of legs. The latter has not been observed in other such cases. Previously there was only evidence that these mites pierce strongly sclerotised parts of the spider exoskeleton to feed, an unusual behaviour so far unexplained.

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. 10. Liphistius ferox sp. nov., left palps of four males; holotype (A-B, E-K), male from Naw Bubaw, matured IV.2019 (C, M), male from Thandaung Gyi, matured 7.X.2014 (D), male from Thandaung Gyi, matured 18.IX.2016 (L). (A) Tarsus and palpal organ, ventral view. (B) Distal part of palpal organ, ventral view; bent and adpressed proximal edge of tegulum indicated by arrow. (C-D) Embolus complex, ventral view. (F) Embolus proper, prodorsal view. (G) Palpal organ, retroventral view. (H) Palpal organ, distal view (dorsal side up). (I) Dorsal part of contrategulum, distal and slightly prolateral view. (J) Distal part of tarsus, ventral view. (K-M) Same, retrolateral and slightly proximal view. Scale lines 1.0 mm (A; B, F-G; C-E; H-I; J; K-M). Abbreviations: tp - triangular distal protrusion of longitudinal rib on sclerotised part of embolus proper; so - angular retrolateral side of sperm duct opening.

Fig. 8. Liphistius tung sp. nov., left palps of male holotype (A-C, G, I-J) and of male paratype (D-F, H). (A) Tarsus and palpal organ, ventral view. (B) Distal part of tibia and proximal part of tarsus, ventral view. (C-D) Palpal organ, distal view (dorsal side up). (E) Distal edge of contrategulum, distal and slightly prodorsal view. (F) Palpal organ, retrolateral view. (G) Same, retroventral view. (H-I) Distal part of palpal organ, ventral and slightly proximal view. (J) Distal part of tarsus and palpal organ, prolateral view. Arrows indicating bent and salient proximal edge of tegulum. Scale lines 1.0 mm (A-B; C-J).

Fig. 11. Liphistius ferox, vulvae of seven females; dorsal view (A, C, E, G, I, K, N, P), ventral view (B, D, F, H, J, L-M, O). (A-B) Thandaung Gyi, moulted 21.VII.2015; with uterus externus attached (in B hidden on other side). (C-D) Thandaung Gyi, moulted 8.1.2015. (E-F) Thandaung Gyi, moulted 15.VII.2015; with uterus externus attached (in F only pocket of one side visible). (G-H) Thandaung Gyi, moulted 16.VII.2015; vulval plate. (I-J) Same female; isolated uterus externus. (K-L) Naw Bubaw, moulted 26.II.2015. (M) Allotype; Thandaung Lay, moulted 10.VII.2015, vulval plate. (N) Same female; isolated uterus externus. (O) Thandaung Gyi, moulted 20.IX.2014; vulval plate. (P) Same female; isolated uterus externus. Arrows indicating paired lateral pockets of still attached membranous uterus externus. Scale lines 1.0 mm.

Fig. 12. Liphistius ferox, vulvae of three females; dorsal view (A, D, F), ventral view (B-C, E). (A-B) Thandaung Gyi, moulted 26.X.2014; vulval plate. (C) Thandaung Gyi, moulted 11.1.2015; vulval plate. (D) Same female; isolated uterus externus. (E) Thandaung Gyi, moulted 6.XII.2014; vulval plate. (F) Same female; isolated uterus externus. Scale lines 1.0 mm.

Fig. 9. Liphistius tung sp. nov., vulval plates of four females; dorsal view (A, C, E, G) and ventral view (B, D, F, H). (A-B) Allotype (taken from specimen). (C-D) Large paratype (taken from specimen). (E-F) Medium-sized paratype (from exuvia 18.IV.2013). (G-H) Small paratype (from exuvia 28.III.2012). Arrow indicating pronounced step between anterior lobes and lateral margin of poreplate. Scale lines 1.0 mm.

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.