Thelcticopis birmanica Thorell, 1895

Sankaran, Pradeep M., Sherwood, Danniella & Jäger, Peter, 2024, On the identity of species of the huntsman spider genus Thelcticopis Karsch, 1884 (Araneae: Sparassidae: Sparianthinae) from India, Myanmar, Pakistan, and Sri Lanka, Zootaxa 5463 (3), pp. 301-338 : 307-311

Thelcticopis birmanica Thorell, 1895 stat. rev.

Figs 6–7 , 26

Thelcticopis birmanica Thorell, 1895: 274 (♀). Pocock 1900: 271 (♀).

Thelcticopis canescens Simon : Gravely 1931: 246, ad part.: fig. 7B [doubtful identity] (♀).

Type material. Holotype ♀, MYANMAR: Tanintharyi: Tenasserim [ca. 12°05’7.3’’N, 99°0’40.95’’E; 47 m a.s.l.], date unknown, E.W. Oates leg., old type number: 1971/212 ( NHMUK 1895.9.21.867; examined).

Diagnosis. Females of T. birmanica stat. rev. resemble T. canescens Simon, 1887 , T. folia Jäger & Praxaysombath, 2009 : fig. 106, T. karnyi Reimoser, 1929 : fig. 3, T. kirankhalapi Ahmed et al., 2015 : figs 4A–B, T. klossi Reimoser, 1929 : fig.2, T. virescens Pocock, 1901 ( Figs 22D–E , 24C herein) and T.zhengi Liu, Li & Jäger, 2010 ( Liu et al. 2010: fig. 4F) by the continuous anterior epigynal margin ( Figs 6C , 7A ). The species can be distinguished from T. folia , T. karnyi , T. kirankhalapi , T. klossi and T. zhengi by its median septum 1.5 times longer than wide (vs. as long as wide or slightly wider than long in T. folia and T. zhengi , and vs. 2.2 to 4 times longer than wide in T. karnyi , T. klossi and T. virescens ). In T. kirankhalapi , the median septum is 1.75 times longer than wide, but it can be easily distinguished by its vulva having a simple duct system running from anterior to posterior broad over its entire length, and by its median septum roughly of the same width over its entire length, whereas T. birmanica has narrow ducts in the anterior half, a bend posteriorly, and a median septum narrowing abruptly in the posterior half (cf. Figs 6C–D , 7B vs. Ahmed et al. 2015: figs 4A–B). The species can be distinguished from T. canescens by having an abruptly narrowing median septum in posterior half (continuously tapering in T. canescens ).

Supplementary description. Female (holotype; Figs 6A–B , 7D–E ). Colouration: brown. [after Thorell 1895: carapace red-brown, clothed with grey setae (partly rubbed off); opisthosoma yellow-brown]. Thoracic striae indistinct. Fovea deep, longitudinal, straight. Chelicerae with three promarginal and seven retromarginal teeth ( Fig. 7E ). Body length 17.5. Carapace 6.5 long. Opisthosoma 8.0 long, 6.38 wide. Chelicerae 1.76 long. Eye sizes and interdistances ( Fig. 7D ): AME 0.40, ALE 0.33, PME 0.27, PLE 0.26; AME–AME 0.43, AME–ALE 0.57, AME– PME 0.45, ALE–PLE 0.58, PME–PME 0.90, PME–PLE 0.88. Legs: I 16.70 (5.12, 2.21, 4.30, 3.86, 1.21), II 16.31 (5.09, 2.25, 4.10, 3.63, 1.24), III 13.67 (4.41, 2.31, 2.77, 2.78, 1.40), IV 18.54 (5.84, 2.27, 4.35, 4.55, 1.53). Leg formula: 4123. Spination: legs: femur I–III 323, tibia I–II 000(10), III–IV 0006, metatarsus I–II 0002, III–IV 0006. Genitalia ( Figs 6C–D , 7A–C ): epigynal field longer than wide, with tiny, anterior bands attached to the anterior margin and one slit sensillum close to the field on the right side ( Figs 6C , 7A ). Lateral lobes short, i.e., roughly one third of epigynal field length, sclerotized, widely separated, with posteriad posterior projections ( Figs 6C , 7A ). Median septum with truncated posterior part ( Figs 6C , 7A ). Copulatory ducts sclerotized, widely separated and with spherical structures in anterior half ( Figs 6D , 7B–C ). Spermathecae large and almost touching each other in posterior half ( Figs 6D , 7B ). Fertilisation ducts short and narrow, tips laterad to slightly antero-laterad ( Figs 7B–C ).

Male. Unknown.

Distribution. Myanmar (Tanintharyi) ( Thorell 1895; Gravely 1931) ( Fig. 26 ).

Remarks. Thorell (1895) described this species based on a female specimen collected from Tenasserim (= Tanintharyi), Burma (= Myanmar). Gravely (1931), with certain hesitation, suggested a possible synonymy of this species with T. canescens , though he did not formally establish it, but this synonymy was subsequently accepted by Roewer (1955). Examination of the holotype of T. birmanica revealed that its epigyne is different from that of T. canescens (as shown in Gravely 1931: fig. 7C based on a female from Tavoy, the type locality of T. canescens ), a species described from Myanmar by Simon (1887b); as already noted by Pocock (1900) and Gravely (1931) the epigyne of T. birmanica presents an epigynal plate with a broad, median cleft accommodating a middle piece with truncated apex vs. narrow, median cleft accommodating a middle piece with rounded apex (cf. Figs 6C , 7A vs. Gravely 1931: fig. 7B). Moreover, Pocock (1900) mentioned that T. birmanica is smaller in size than T. canescens . As a consequence, we remove T. birmanica stat. rev. from the synonymy of T. canescens and consider it as a valid species.

Figures

FIGURES 6A–E. Thelcticopis birmanica Thorell, 1895 stat. rev., holotype female. A–B Habitus (A dorsal, B ventral); C Epigyne, ventral; D Vulva, dorsal; E Labels in the holotype vial. Scale bars: A–D, 1 mm. Photographs by Danniella Sherwood, © The Trustees of the Natural History Museum, London.

FIGURES 7A–E. Thelcticopis birmanica Thorell, 1895 stat. rev., holotype female. A Epigyne, ventral; B–C Vulva (B dorsal, C anterior); D Eye arrangement, dorsal; E Left chelicera, ventral. Abbreviations: AB—anterior band of epigynal field; CD— copulatory duct; EF—epigynal field; FD—fertilisation duct; LL—lateral lobe; MS—median septum; S—spermatheca; SS—slit sensillum. Drawings by Peter Jäger.

FIGURES 22A–F. Thelcticopis virescens Pocock, 1901, non-type male (A, C) (ZSI/WGRC/I.R.INV.26583) and female (B, D–F) (ZSI/WGRC/I.R.INV.26585). A–B Habitus, dorsal; C Left palp, ventral; D–E Epigyne, ventral (D not dissected, E same dissected and cleared in 10% KOH); F Vulva, dorsal. Scale bars: A–C, 2 mm; D–F, 1 mm. Photographs by Pradeep Sankaran.

FIGURES 24A–D. Thelcticopis virescens Pocock, 1901, genitalia of non-type male (A–B) (ZSI/WGRC/I.R.INV.26583) and female (C–D) (ZSI/WGRC/I.R.INV.26585). A–B Left palp (A ventral, B retrolateral); C Epigyne, ventral; D Vulva, dorsal. Abbreviations: aE—apical filiform part of embolus; bE—basal wide flattened part of embolus; bpC—basal process of conductor; C—conductor; CD—copulatory duct; CO—copulatory opening; CS—cymbial scopula; dRTA—dorsal part of RTA; FD—fertilisation duct; GA—glandular appendage; LL—lateral lobe of epigyne; MS—median septum; RTA—retrolateral tibial apophysis; S—spermatheca; Sp—spermophor; T—tegulum; TA—tegular apophysis; VDL—ventro-distal lobe of palpal tibia; vRTA—ventral part of RTA. Arrow indicates beak-like process of conductor. Scale bars: A–B, 2 mm; C–D, 1 mm. Drawings by Pradeep Sankaran.

FIGURE 26. Distribution of species of the genus Thelcticopis Karsch, 1884 in Myanmar, India, Pakistan and Sri Lanka. For species in southern India and Sri Lanka (except for T. kirankhalapi), see Fig. 27.