Latouchia incerta, Decae & Schwendinger & Hongpadharakiree, 2021

Decae, Arthur E., Schwendinger, Peter J. & Hongpadharakiree, Komsan, 2021, Descriptions of four new trapdoor spider species in the subfamily Ummidiinae from Thailand (Araneae, Mygalomorphae, Halonoproctidae), Zootaxa 4984 (1), pp. 300-323 : 312-315

Latouchia incerta spec. nov.

Figs 8 A−J, 9A−J, 12, 15C−D

Type material. THAILAND: Buri Ram Province: Holotype ♂ (PS-008, sample TH-04/19, MHNG), Buri Ram District, Khao Kradong Forest Park, 14.9378°N, 103.0937°E, 180–300 m elevation, P.J. Schwendinger leg. 16.+ 18.12.2004 . Paratypes: 2 ♀ (1 ♀: PS-010, sample TH-04/19, MHNG; 1 ♀: PS-011, sample TH04/19, THNHM), with same data as for holotype . 1 ♀ (PS-012, sample TH-05/18, MHNG), from type locality, P.J. Schwendinger leg. 15.12.2005 . 1 ♀ (PS-013, sample TA-13/04, MHNG) from type locality, 280 m elevation, P.J. Schwendinger leg. 3.1.2014.

Additional material examined. THAILAND: Surin Province: 1 ♂ (PS-009, sample TH04/18) Prasat District, Khao Phanom Sawai Forest Park, 14.7601°N, 103.3659°E, 200 m elevation, collected as juvenile 15.12.2004, matured 10.3.2006. 1♀ (sample TA-13/08), 4 ♂ (PS-032 to PS-035, sample TA-13/08; matured 10.1., 17.1., 14.2. and 19.2.2014, respectively), Surin District, near Ramkamhaeng University Campus , 14.9166°N, 103.4572°E, 150 m elevation, 12.12.2013 . 1♀ (sample TL-15/09), Surin District, forest near Surin Central Prison , 14.8766°N, 103.4566°E, 150 m elevation, 9.7.2014 (all specimens P.J. Schwendinger leg.; all MHNG).

Etymology. The specific epithet is a Latin adjective, meaning “uncertain, unreliable, undecided” etc., pointing towards the somewhat uncertain placement of this species in the genus Latouchia .

Diagnosis. Different from all known Latouchia species for which sufficient information is available, with the exception of L. schwendingeri Decae, 2019 , L. huberi Decae, 2019 and L. maculosa spec. nov., by the distinctly racemose spermathecae ( Figs 9 E−J). Different from L. huberi by the short, not columnar spermathecae ( Figs 9 E−J cf. Decae 2019: figs 46−47); from L. schwendingeri by the non-pyriform proximal part of the palpal organ and the long, sharply pointed embolus ( Figs 8 F−J cf. Decae 2019: figs 23−26); from L. maculosa spec. nov. by short and wide spermathecae ( Figs 9 E−J cf. Figs 11 E−L), by the more sturdy embolus with a distinctly bent tip (at an angle of about 45°, n = 2) furnished with a subterminal protuberance connected to the pointed tip by a thin membranous keel ( Figs 8 F−J cf. Figs 10 F−J).

Description. Male (holotype). Specimen preserved for 16 years in 70% ethanol in good condition except for the shrunken opisthosoma ( Fig. 8A ). General colouration: carapace reddish brown, darker along its edges; chelicerae light brown; opisthosoma dorsally dark grey, with fine light grey speckles, its ventral side anterior of epigastric furrow, book-lung covers and spinnerets cream-coloured; legs yellowish brown, anterior ones slightly darker than posterior ones; palps darker brown than legs; sternum and labium yellow.

Morphology: Carapace ( Fig. 8A ) coriaceous, slightly longer than wide (CW/CL = 0.9); its cephalic part only very slightly elevated, with a weak saddle-shaped depression behind eye group; thoracic part sloping down from fovea to posterior margin at a 30° angle. Clypeus very narrow; ocular tubercle dome-shaped; eye group trapezoidal, slightly more than twice as wide as long (EL/PR = 0.45); AME slightly more than their diameter apart from each other (disAME/diaAME = 1.13); PR slightly procurved. Chelicerae with rastellum on low process; fangs smooth. Palpal coxae with short rounded prolateral-distal lobe; cuspules absent. Sternum anteriorly narrowed; central sigillum indistinctly developed. Labium without cuspules; labiosternal suture shallow. Palps ( Fig. 8B ) slender, strongly elongated; femur distinctly longer than tibia (PFem/PTib = 1.5), with dorso-distal group of short, strong spines; tibia not inflated (TibW/PTib = 0.2); cymbium aspinose, with few clavate dorsal trichobothria. Palpal organ ( Figs 8 F−J) with proximal part pyriform; embolus sturdy, proximally widest and distally tapering to a pointed tip connected by a membranous keel to a small subterminal protuberance ( Fig. 8J ); distal part of embolus slightly curved in pro- and retrolateral view ( Figs 8G, I ), bent at an angle of about 45° in ventral and dorsal view ( Figs 8F, H ).

Tarsi of legs I ( Fig. 8C ) and II not inflated, with ventral scopula, without spines, carrying few clavate dorsal trichobothria; metatarsi with prolateral-distal spines; tibiae and patellae ventrally and prolaterally with strong straight spines (reduced on leg II); femur with a group of short spines dorso-distally. Legs III and IV elongated; tibia III unmodified ( Figs 8 D−E); slender spines on metatarsi, tibiae and femora, short strong spines on patellae. Leg formula 4123. PTC of anterior legs with a short comb of teeth proximally; PTC of posterior legs with one or two teeth. Opisthosoma ovoid, anteriorly narrowed, not warty, clothed with curved bristles. Spinnerets: PLS and PMS close to each other; PMS cylindrical, with light-coloured apical spigot field, slightly more than their diameter apart from each other; PLS short, conical, with macrospigots on ventral side of median article only.

Measurements. TBL 10.0; CL 4.8; CW 4.2; CP 2.9; AR 0.88; PR 0.92; EL 0.41; diaALE 0.23; diaPLE 0.14; diaAME 0.16; diaPME 0.11; disALE 0.49; disPLE 0.67; disAME 0.18; disPME 0.36; SL 2.9; SW 2.2; LL 0.7; LW 0.8; palp 11.1 (0.7 + 3.2 + 2.6 + 4.6); leg I 14.7 (1.7 + 3.2 + 3.0 + 2.2 + 4.6); leg II 13.3 (1.7 + 3.0 + 2.5 + 1.9 + 4.2); leg III 12.0 (2.1 + 3.2 + 2.0 + 1.6 + 3.1); leg IV 15.5 (2.2 + 4.0 + 3.2 + 2.0 + 4.1); BuL 1.30; BuW 0.53; EmL 0.57.

Female (paratype; PS-010). Specimen preserved for 16 years in 70% ethanol in good condition except for small damage to dorsal cuticle of opisthosoma. General colouration: carapace yellow, with dark-coloured margin; chelicerae light brown; legs and palps yellowish brown; sternum and labium uniformly yellowish brown; opisthosoma with dorsal side dark purplish grey, ventral side as in male.

Morphology: Carapace ( Fig. 9A , showing paratype PS-013) longer than wide (CW/CL = 0.9), posteriorly narrowing, surface smooth, with fine bristles in highest part. Clypeus and ocular tubercle as in male; eye group more compact (EL/PR = 0.62) and AME further apart from each other (disAME/diaAME = 0.71) than in male. Chelicerae with rastellum of seven strong teeth placed in a curved row on a low process; fang smooth. Palpal coxae with 11 and 12 cuspules in a compact proximal group; prolateral-distal lobe absent. Sternum with large fig-leaf-shaped cental sigillum. Labium with four distal cuspules; labiosternal suture narrow. Palps as described above for Ummidiinae ; palpal claw with two strong teeth on a common base. Legs I and II as described for Ummidiinae above. Leg III very strong; tarsus with ventro-distal group of stiff bristles; metatarsus with numerous short, strong spines closely grouped in dorso-lateral area (on both sides); tibia shortened (FemIII/TibIII = 2.3) and dorso-proximally narrowing to form a “demi-saddle” ( Figs 9B–C , showing paratype PS-013); groups of short strong spines on dorso-lateral side of tibia and on apical and prodorsal sides of patella; femur aspinose, ventrally inflated. Tarsus of leg IV with ventro-distal group of stiff bristles and few spiny bristles; metatarsus with few stiff bristles on ventral side, otherwise aspinose; patella with dorso-proximal group of short stiff bristles. PTC of all leg tarsi with two proximal teeth on common basis. Leg formula 4123. Opisthosoma narrowing at both ends, without warty bristle sockets. Spinnerets as in male. Spermathecae very short, purse-like and distinctly racemose (cauliflower-shaped, surface with numerous vesicles) ( Fig. 9F ).

Measurements. TBL 16.1; CL 6.9; CW 5.9; CP 4.3; AR 1.12; PR 1.04; EL 0.64; diaALE 0.32; diaPLE 0.24; diaAME 0.15; diaPME 0.18; disALE 0.63; disPLE 0.74; disAME 0.19; disPME 0.44; SL 4.8; SW 3.7; LL 1.2; LW 1.4; palp 11.4 (2.2 + 2.7 + 2.4 + 4.1); leg I 12.2 (1.1 + 1.8 + 2.6 + 2.6 + 4.1); leg II 11.6 (1.2 + 1.9 + 2.2 + 2.5 + 3.8); leg III 12.3 (1.9 + 2.4 + 1.6 + 2.7 + 3.7); leg IV 15.4 (1.8 + 3.2 + 3.1 + 2.7 + 4.6).

Variation. Males (n = 6): TBL 10.0−14.5; CL 4.8−6.5; CW 4.2−5.6; CP 2.9−4.0; AR 0.88−1.22; PR 0.92−1.22; EL 0.41−0.61; diaALE 0.23−0.33; diaPLE 0.14−0.19; diaAME 0.15−0.20; diaPME 0.11−0.17; disALE 0.49−0.64; disPLE 0.67−0.89; disAME 0.09−0.18; disPME 0.36−0.46; SL 2.9−3.9; SW 2.2−3.0; LL 0.7−0.8; LW 0.8−1.1; palp 11.1−13.0; leg I 14.8−18.9; leg II 13.3−17.4; leg III 12.0−15.8; leg IV 15.5−20.5. Males of L. incerta spec. nov. show a remarkable phenotypic diversity in size ( Figs 8A , 12 ). This is remarkable because conspecific males of fossorial mygalomorph spiders of the same generation are generally believed to mature more or less in concert and to swarm during a relatively short mating season. They are therefore expected to be rather uniform in size.

Females (n = 5): TBL 14.1−18.6; CL 5.9−6.9; CW 5.2−5.9; CP 3.7−4.3; AR 1.09−1.20; PR 1.04−1.21; EL 0.57−0.69; diaALE 0.32−0.37; diaPLE 0.22−0.30; diaAME 0.13−0.17; diaPME 0.17−0.24; disALE 0.54−0.63; disPLE 0.74−0.80; disAME 0.13−0.19; disPME 0.37−0.44; SL 4.0−4.8; SW 3.2−3.7; LL 1.0−1.2; LW 1.1−1.4; palp 10.0−11.3; leg I 11.1−12.3; leg II 10.3−11.5; leg III 11.1−12.3; leg IV 13.5−15.2. Variation in the shape of the spermathecae of six females is shown in Figs 9 E−J.

Habitat and biology. The specimens examined were collected from roadsides and earth banks in seasonally dry deciduous forests between 150 and 300 m elevation. At Khao Kradong L. incerta spec. nov. and C. isan spec. nov. occur together, their burrows only a few metres away from each other. The type specimens of L. incerta spec. nov. were taken from relatively long (up to 10 cm), densely lined burrows closed by a single, rather thick (cork-type) trapdoor with a maximum length of 1.2 cm and a maximum width of 1.3 cm. This burrow structure is different from that of the co-occurring Conothele isan spec. nov. The males from Khao Phanom Sawai and Surin, however, were taken from much shorter burrows (2.5–4.5 cm long) which had thinner trapdoors, 0.85–1.0 cm long and 0.9–1.1 cm wide. The burrow structure of this species thus appears to be quite variable.

The six available males matured in captivity in Geneva between mid-January and early March. The phenology seems to be quite similar to that of C. isan spec. nov. The spiders quite effectively prevented attempts to force open the trapdoor by vigorously pulling it shut from inside. Outside their burrows spiders of both sexes responded aggressively to any disturbance and were ready to bite. Males took a defence posture by raising their long pedipalps high (almost vertical) above the body ( Figs 15 C−D).

Figures

FIGURES 8A−J. Latouchia incerta spec. nov., holotype male. A Habitus, dorsal. B Left palp, retrolateral. C Tarsus and distal part of metatarsus of left leg I, retrolateral. D–E Left tibia and patella III (D prolateral, E retrolateral). F−I Right palpal organ, clock-wise rotated by 90° (F ventral, G prolateral, H dorsal, I retrolateral). J Embolus tip, retrolateral. Abbreviatons: el—elongated articles of palp, k—keel of embolus tip.

FIGURES 9A−J. Latouchia incerta spec. nov., females (A−D, I paratype PS-013; E Surin, prison, 150 m; F paratype PS-010; G paratype PS-012; H paratype PS-011; J Surin, Ramkhamhaeng, 150 m). A Habitus, dorsal. B–C Right tibia and patella III (B prolateral, C retrolateral). D Spinnerets, ventral. E−J Variation in the monopartite spermathecae of six specimens (note short, compact racemose structures). Abbreviatons: ds—demi-saddle, ms—macro spigots on medial article of PLS, sf—distal spigot field on PMS.

FIGURES 10A−J. Latouchia maculosa spec. nov., holotype male. A Habitus, dorsal. B Left palp, retrolateral. C Tarsus and distal part of metatarsus of left leg I, retrolateral. D–E Left tibia and patella III (D prolateral, E retrolateral). F−I Right palpal organ, clock-wise rotated by 90° (F ventral, G prolateral, H dorsal, I retrolateral). J Embolus tip, dorsal.Abbreviations: bt—bent tip of embolus, el—elongated articles of palp, sp—sharp point of embolus tip.

FIGURES 11A−L. Latouchia maculosa spec. nov., females (A−E paratype PS-026; F paratype PS-027; G Huay Yang, 90 m; H paratype PS-036; I Pala-U, 290 m, J−L presumably conspecific specimens from north of Prachuap Khiri Khan Province, not listed). A Habitus, dorsal. B–C Right tibia and patella III (B prolateral, C retrolateral). D Spinnerets, ventral. E−L Variation in the monopartite spermathecae of eight different specimens (note long, conical, racemose structures). Abbreviations: ds—demisaddle, ms—macro-spigots on distal and medial article of PLS.

FIGURES 12A–D. Latouchia incerta spec. nov., males, variation in the habitus of four ethanol-preserved non-type specimens. Scale line: 10 mm.

FIGURES 15A−D. Living male spiders in laboratory setting. A−B Latouchia maculosa spec. nov., habitus (A adult male, B subadult male; note opisthosomal pattern referred to by the species name ‘maculosa’). C−D L. incerta spec. nov. (C defence behaviour of adult male, lateral, note strongly raised palps; D the same in rear view).