Leptothele chang Schwendinger, 2020

Schwendinger, Peter J., Lehmann-Graber, Christina, Hongpadharakiree, Komson & Syuhadah, Nurul, 2020, New euagrid spider species from Thailand and Malaysia, and new localities of Leptothele bencha (Arachnida: Araneae), Revue suisse de Zoologie 127 (2), pp. 423-453 : 431-435

Leptothele chang Schwendinger , sp. nov.

Figs 1 G-H, K, 5-7

Holotype: MHNG (sample THMA-00/08); male (matured 24.I.2001); THAILAND, Trang Province, Nayong District, Tham Khao Chang Hai , 7°35’24”N, 99°40’05”E, 50 m; 1. & 5.VIII.2000; leg. P.J. Schwendinger.

Paratypes: MHNG; 3 males (matured 13.I., 8.II., 10.IX.2001) and 13 females (allotype moulted 17.I.2001); same collecting data as for holotype. – THNHM; 1 male (matured 2.IV.2001) and 1 female; same collecting data as for holotype.

Etymology: Thai: chang (pronounced with a high tone and a long “a”) = elephant. The epithet refers to the type locality, the Tham Khao Chang Hai (= cave of the mountain in which an elephant vanished) and to the size of the new species: it is the larger one of the two known Leptothele species. In colloquial Thai a big or tall person is often referred to as “tua chang” = with the body of an elephant.

Diagnosis: Distinguished from L. bencha by larger size and paler body colouration. Males with longer bulbous part of palpal organ ( Fig. 6 A-E cf. Fig. 3A, D, G; H being an exception), with 2-3 ventral megaspines on tibia II ( Fig. 6 G-K; in L. bencha normally two, Fig. 3 B-C, E-F, four being an exception, Fig. 3 I-J), with wrinkles in front and behind subdistal-ventral ridge on tibia II ( Fig. 6 H-K; wrinkles absent in L. bencha ), and with a less pronounced, lower and basally wider ventral process on metatarsus II ( Fig. 6G cf. Fig. 3B, E, I ). Females with relatively shorter and wider spermathecae, median receptacles with very long and thin stalks ( Fig. 7 cf. Fig. 4 ).

Description: MALE (holotype). Colour in alcohol (slightly darker in life) mostly light brown; sternum, opisthosoma and ventral side of body and limbs slightly lighter; prolateral zone of palpal coxae and all membranes cream-coloured; eye mound black ( Fig. 5 A-B).

Body 6.70 long. Carapace 2.58 long, 2.30 wide, oval, almost flat, thoracic part slightly higher than cephalic part, quite densely covered with fine, slightly wavy hairs, longest and strongest ones on posterior margin; a few bristles in front of eye mound; two long bristles in front of pitlike fovea.

Eyes on low mound; eye group 0.26 long, anterior eye row slightly procurved, 0.45 wide, posterior eye row slightly recurved, 0.48 wide. Eye diameters and interdistances: AME 0.09, ALE 0.17, PME 0.10, PLE 0.11; AME- AME 0.02, PME-PME 0.13. MOQ 0.20 long, 0.20 wide anteriorly, 0.35 posteriorly.

Chelicerae weak, without intercheliceral tumescence, each groove with 10 teeth on promargin and a short row of tiny medioproximal denticles. Palpal coxae 0.65 long, 0.35 wide; anterior lobe indistinct, with serrula composed of a band of denticles (see Fig. 1K showing female paratype); no cuspules. Labium 0.15 long, 0.50 wide, without cuspules; anterior edge distinctly setose, followed by pallid zone without setae; posterior part pigmented, with few short setae. Sternum 1.30 long, 1.20 wide, cordate; labiosternal suture fused with anterior pair of sigilla, three pairs of free sigilla indistinct and marginal.

Palps ( Fig. 6 C-E): Measurements: total length 3.75 (1.35 + 0.90 + 0.90 + 0.60). Several long strong bristles dorsally and ventrally on all articles, especially on femur and tibia; tarsus with two dorsodistal spines, plus one weak spine (or strong bristle) on each side disto-laterally. Trichobothria: 6+ 7 in two rows on tibiae, 8 in an irregular row on tarsi. Palpal organ with a narrow kidney-shaped subtegulum, a much longer and wider, asymmetrically pyriform tegulum, and a quite long (about as long as tegulum), thin embolus tapering to a slightly curved tip.

Legs 2134. Leg I 8.80 long (2.45 + 1.30 + 1.90 + 1.90 + 1.25); leg II 8.18 long (2.35 + 1.20 + 1.53 + 1.80 + 1.30); leg III 8.85 long (2.30 + 1.10 + 1.80 + 2.25 + 1.40); leg IV 11.13 long (2.85 + 1.25 + 2.50 + 2.98 + 1.55). All tarsi evenly deep for entire length (not bulged on ventral side), not pseudosegmented and without spines ( Fig. 5H ); with a few scopuliform hairs (see Fig. 10 C-E for Malayathele cameronensis sp. nov.) in distal portion, on anterior tarsi more distinct than on posterior tarsi. Metatarsal preening combs absent. Leg I: Metatarsus with 1/2 proximoventral spines and 2 distoventral spines; tibia not incrassate, not ventrally flattened, carrying 1 prolateral spine and 14/16 ventral spines; patella with a row of bristles retroventrally-distally ( Fig. 6F ); femur in median third with a short band of hooked spinules retrodorsally ( Fig. 5G ). Leg II: Ventral side of metatarsus with a low, basally wide, mound-like process in proximal third ( Figs 5E , 6 G-I). Tibia slightly incrassate, without band of elongate spinules on prolateral side ( Figs 5E , 6G ); ventral spur low, carrying 2/3 megaspines; low, sharp transversal ridge subdistally on ventral side of tibia lying in a lanceolate area covered by wrinkles ( Fig. 6 G- I). Band of hooked spinules proventrally on femur short, distant from distal margin of leg article ( Fig. 5F ).

Spines, trichobothria and claws of legs. All femora with numerous long strong bristles dorsally; I: patella d1; tibia p1, v14/16; metatarsus v3/4. II: patella d1; tibia p2, v2/3 (megaspines); metatarsus p2, v3. III: patella d3; tibia d2, p2, r1/2, v6; metatarsus d6, v6. IV: patella d3; tibia d1, p2, r2, v5/6; metatarsus d7/8, v5/7. Trichobothria: 7+ 7 in two rows on tibiae, 12 in a single row on metatarsi, 8 in a single row on tarsi. Paired tarsal claws with 11-14 teeth in one row on anterior legs, 9-11 on posterior legs; unpaired claw with 6 teeth on legs I-III, 5 on leg IV.

Opisthosoma 3.45 long, 2.25 wide; densely covered with fine adpressed grey hairs interspersed with longer brown bristles (longest on anterior margin). PMS 0.50 long, 0.10 wide in the middle, separated from each other by 0.90; PLS 3.65 long (proximal article 1.10 long and 0.30 wide, median article 1.15 long and 0.20 wide, distal article 1.4 long and 0.13 wide in the middle), separated from each other by 0.68. Distal article of PLS with a pseudosegmentation at mid-point (see Fig. 5I showing male paratype).

FEMALE (allotype). Colour in alcohol (slightly darker in life) mostly light reddish brown; chelicerae distinctly darker, opisthosoma and ventral side of body and limbs (especially sternum) lighter ( Fig. 5 C-D).

Body 9.63 long. Carapace 3.54 long, 3.07 wide, oval, almost flat, thoracic part as high as cephalic part, with hairs as in male. Eye group 0.29 long, anterior eye row slightly procurved, 0.55 wide, posterior eye row slightly recurved, 0.63 wide. Eye diameters and interdistances: AME 0.11, ALE 0.17, PME 0.11, PLE 0.12; AME- AME 0.06, PME-PME 0.24. MOQ 0.23 long, 0.26 wide anteriorly, 0.47 posteriorly.

Chelicerae stronger than in male, each groove with 12/13 teeth on promargin and a short row of 13/14 tiny medioproximal denticles. Palpal coxae 0.96 long, 0.59 wide; anterior lobe indistinct, serrula as in Fig. 1K ; no cuspules. Labium 0.22 long, 0.68 wide, without cuspules. Sternum 1.65 long, 1.71 wide, cordate, with distinct labiosternal suture (fused with anterior pair of sigillae) and three free pairs of indistinct marginal sigilla.

Palps 5.81 long (1.89 + 1.09 + 1.40 + 1.43). Spination: several long strong bristles dorsally and ventrally on all articles, especially on femur and tibia; tarsus with 8/9 spines ventrally. Trichobothria: 6/7+6/ 7 in two rows on tibiae, 8 in an irregular row on tarsi.

Legs 2134. Leg I 9.28 long (2.67 + 1.52 + 1.99 + 1.89 + 1.21); leg II 8.94 long (2.55 + 1.43 + 1.86 + 1.89 + 1.21); leg III 9.58 long (2.55 + 1.40 + 1.93 + 2.33 + 1.37); leg IV 11.73 long (3.04 + 1.55 + 2.61 + 2.98 + 1.55). Tarsi without spines and without discernible scopuliform hairs. Metatarsal preening combs absent.

Spines, trichobothria and claws of legs. All femora with numerous long strong bristles dorsally; I: patella d2; tibia p3, v4/6; metatarsus v6. II: patella d2; tibia p3, v5/6; metatarsus p2, v5/6. III: patella d3; tibia d2, p2/3, r2/3, v5/6; metatarsus d5, p1/2, r1/2, v6. IV: patella d3; tibia d2/3, p2, r3, v5/6; metatarsus d5, p2, r1/2, v6. Trichobothria: 7-8+ 7-8 in two rows on tibiae; 13-16 in one row on metatarsi; 8-9 in one row on tarsi. Paired tarsal claws with 12-15 teeth in a row on anterior legs, 10-12 on posterior legs; unpaired claw with 6 teeth on anterior legs, 5 on posteriors (see Fig. 1 G-H showing female paratype).

Opisthosoma 5.40 long, 3.76 wide, with hairs as in male. PMS 0.68 long, 0.19 wide in the middle, separated from each other by 1.18; PLS 5.49 long (proximal article 1.77 long and 0.43 wide, median article 1.55 long and 0.34 wide, distal article 2.17 long and 0.22 wide in the middle), separated from each other by 1.43. Distal article of PLS with a pseudosegmentation at mid-point.

Spermathecae medium-long and moderately wide; lateral receptacles with narrowly rounded heads and no stalks; median receptacles with globular heads and very long (about twice as long as heads) and thin stalks, their walls not sclerotised ( Fig. 7A ).

Variation: Carapace lengths in males (n = 5) range 2.30-2.73, carapace width 2.03-2.43. In the largest female the carapace length is 3.57, the carapace width 3.10; the smallest reproductive female (constructed three egg sacs) has a carapace length of 2.48 and a carapace width of 2.26. Two males (including the holotype) have three ventral megaspines on the left tibia II and two megaspines on the right tibia II; the other three males have two megaspines on both tibiae II. Variation in the number of ventral megaspines (two probably being more common than three) on tibia II in this species appears to be much greater than in L. bencha (only a single, asymmetrical case among 24 specimens examined, and that is a very unusual tibia II with a very low ventral spur carrying four megaspines). A similar tibia II megaspine variation is known from Phyxioschema suthepium (45 males with 2+2, 2 with 2+3, 1 with 3+3; n = 48), P. huberi (5 males with 2+2, 3 with 3+3, 1 with 3+4, 1 with 4+5; n = 10) and P. eripnastes (3 males with 2+2, 1 with 2+3; n = 4) ( Schwendinger, 2009). There are 11-16 ventral and 1-2 prolateral spines on tibia I, and metatarsus I has mostly two (on one leg three) distal spines, 0-2 median spines and 1-2 proximal spines. One male paratype has three dorsodistal spines (two strong, one weak) on both palpal tarsi, all other males have only two such spines. Variation in the shape of the vulva of four females is shown in Fig. 7 . The allotype has lateral receptacles without recognizable stalks ( Fig. 7A ), whereas in the other females the stalks are more or less constricted ( Fig. 7 B-D). One of the females examined has a tiny secondary receptacle situated anterior of the median receptacle on one of its spermathecae ( Fig. 7C ).

Distribution and habitat: Leptothele chang sp. nov. is only known from its type locality in southern Thailand ( Fig. 2 , locality 11). Unlike the closely related L. bencha , the new species occurs quite far away from the coast, at the entrance of a limestone cave, but seemingly not in the dark parts of the cave or in the surroundings of the cave.

Biology: The type specimens were all collected from irregular tunnel webs spun between discarded wooden poles in the oligophotic zone and in holes and cracks in dry soil at the entrance of a limestone cave. When collected at the beginning of August, one female had a hemispherical egg sac (containing 28 eggs) suspended in the aerial portion of its web. Another female built an egg sac in captivity at the beginning of October of the same year. Six preserved egg sacs, four of them resulting from mating in captivity during the following year, contain 14- 44 eggs and early instar spiderlings. These egg sacs were built 20-24 days after mating (4 observations). Females built up to three egg sacs and moulted three times per year. Males matured in captivity in January, February, April and November. There appears to be no limited mating period. Mating was performed as described for L. bencha in this text, with the tibia II coupling spurs and megaspines of the male locking onto femora II of the female and pushing them to the side. Then he very abruptly and forcefully pulled her towards him whilst bending her prosoma and anterior limbs backwards into the mating position. The first act of mating lasted only three minutes, but was repeated three times consecutively. The second copula of the same male, but with another female, was performed only once and it lasted for 20 minutes.

Figures

Fig. 1. Photos of unpaired leg claws, lateral view (A-J), and of serrula on palpal coxa, anteroventral view (K-L). (A) Masteria cf. cavicola (Simon, 1892), female (in MHNG; 13.IV.1977; leg. P. Strinati & V. Aellen) from a cave near Bagio, Luzon, the Phillipines, leg II. (B) Same, leg IV.(C) Phyxioschema huberi Schwendinger, 2009, exuvia of female paratype, leg I. (D) Same, leg IV. (E) Leptothele bencha, female from Ko Sirey, leg I. (F) Same, leg III. (G) Leptothele chang sp. nov., exuvia of female paratype, leg I. (H) Same, leg III. (I) Malayathele ulu sp. nov., exuvia of female paratype, leg I. (J) Same, leg IV. (K) Leptothele chang sp. nov., exuvia of female paratype. (L) Malayathele kanching sp. nov., exuvia of female paratype. Not to scale.

Fig. 6. Leptothele chang sp. nov.; male paratype (A-B, J-K) and male holotype (C-I). (A) Right palpal organ, ventral view. (B) Left palpal organ and palpal tarsus, prolateral view. (C) Right palpal organ and palpal tarsus, ventral view. (D) Left palpal organ and palpal tarsus, ventral view. (E) Right palpal organ and palpal tarsus, prolateral view. (F) Patella to metatarsus of left leg I, ventral view. (G) Patella to metatarsus of left leg II, prolateral view. (H) Same, ventral view. (I) Same of right leg II, ventral view. (J) Right tibia II, ventral view. (K) Left tibia II, ventral view. Scale lines 1.0 mm (A-E; F-K).

Fig. 3. Leptothele bencha; males from Ko Sirey (A-B), Ko Tarutao (C-F, G, showing two specimens), Ko Libong (H) and Ko Sukon (I- J). (A, D, H) Distal part of palp, ventral view. (B, E) Right tibia and metatarsus II, prolateral view. (C) Left tibia and metatarsus II, ventral view. (F) Right tibia and metatarsus II, ventral view. (G) Palpal organ, ventral view. (I) Left tibia and metatarsus II of aberrant specimen, prolateral view. (J) Same, ventral view. Scale line 1.0 mm.

Fig. 7. Leptothele chang sp. nov.; vulvae of female allotype (A) and of three female paratypes (B-D), dorsal view. (A) Drawn from exuvia of allotype; cuticular gland duct bases visible. (B-D) Drawn from dissected paratypes; gland duct bases not visible but gland pores instead. (C) Right lateral receptacle carrying a tiny secondary receptacle. Scale lines 0.1 mm.

Fig. 4. Leptothele bencha; vulvae of six females, dorsal view. (A) Female from Ko Libong. (B-C) Two females from Ko Tarutao. (D) Female from Ko Lanta. (E-F) Two females from Ko Siray. Scale lines 0.1 mm.

Fig. 5. Leptothele chang sp. nov.; male holotype (A-B, E-H), female allotype (C-D) and male paratype (I). (A, C) Habitus, dorsal view. (B, D) Habitus, ventral view. (E) Femur to metatarsus of right leg II, prolateral view. (F) Right femur II, proventral view. (G) Right femur I, retrodorsal view. (H) Tarsus I, lateral view. (I) Distal part of median article and entire distal article of PLS, lateral view; arrow indicating pseudosegmentation. Not to scale.

Fig. 10. Malayathele cameronensis sp. nov., male holotype. (A) Left leg I, retrolateral view; one ventral spine on tibia fallen off. (B) Left leg II, prolateral view. (C) Unpaired claw and scopuliform hairs of left leg II, prolateral view. (D) Ventrally bulged tarsus of left leg II, prolateral view. (E) Scopuliform hair on left tarsus II. Not to scale.

Fig. 2. Localities of Leptothele spp. and Malayathele spp. on the Thai-Malay Peninsula. The coast of Sumatra is omitted. 1 - Ko Sirey (L. bencha); 2 - Ko Yao Noi (L. bencha); 3 - Khao Phanom Bencha (L. bencha, type locality); 4 - Thab Khaek - Hang Nak Hill and Khlong Jilat (L. bencha); 5 - Ban Chong Phlie (L. bencha); 6 - Ko Lanta (L. bencha); 7 - Ko Muk (L. bencha); 8 - Ko Libong (L. bencha); 9 - Ko Sukon (L. bencha); 10 - Ko Tarutao (L. bencha); 11 - Tham Khao Chang Hai (L. chang sp. nov., type locality); 12 - Ulu Groh (M. ulu sp. nov., type locality); 13 - Chenderiang (Malayathele sp.); 14 - Cameron Highlands (M. cameronensis sp. nov., type locality; M. ulu sp. nov.); 15 - Fraser’s Hill (M. maculosa sp. nov., type locality); 16 - Genting Highlands (M. maculosa sp. nov.); 17 - Templer Park (M. kanching sp. nov.; type locality); 18 - Ulu Gombak (M. kanching sp. nov.); 19 - Jeram Pasu Waterfall (Malayathele sp.); 20 - Singapore (Euagridae/Dipluridae gen. sp.).