Trachecymbius bosselaersi, Haddad & Lyle, 2024

Haddad, Charles R. & Lyle, Robin, 2024, Three new genera of arboreal dark sac spiders from southern Africa (Araneae: Trachelidae), Zootaxa 5399 (5), pp. 451-504 : 492-493

Trachecymbius bosselaersi sp. nov.

Figs 215 , 222, 223

Etymology. This species is named for Jan Bosselaers, in recognition of his pioneering systematic research on Trachelidae and related spiders.

Diagnosis. The female is easily recognised by the Y-shaped arrangement of the connecting ducts of the spermathecae and the peculiar shape of the ST II, comprising a long slender stalk originating from the copulatory duct and terminating in a globose receptacle anterolaterally ( Figs 222, 223 ). Male unknown.

Female (holotype, Hogsback, NCA 2014/607). Measurements: CL 1.06, CW 0.85, AL 1.32, AW 1.08, TL 2.47, FL 0.05, SL 0.64, SW 0.52, AME-AME 0.03, AME-ALE 0.02, ALE-ALE 0.17, PME-PME 0.08, PME-PLE 0.07, PLE-PLE 0.33. Length of leg segments (sequence from femur to tarsus, and total): I 0.70 + 0.38 + 0.52 + 0.44 + 0.30 = 2.34; II 0.62 + 0.33 + 0.46 + 0.41 + 0.29 = 2.11; III 0.51 + 0.27 + 0.32 + 0.40 + 0.21 = 1.71; IV 0.68 + 0.32 + 0.56 + 0.57 + 0.24 = 2.37.

Carapace deep orange-brown, with faint grey mottling ( Fig. 215 ); carapace surface granulate, more pronounced on slopes; fovea indistinct, shallow, at ⅘ CL. AER procurved; clypeus height equal to ¾ AME diameter; ALE larger than AME; AME separated by distance equal to ½ their diameter; AME separated from ALE by distance equal to ¼ AME diameter; PER strongly recurved; PLE larger than PME; PME separated by distance equal to ⅘ their diameter; PME separated from PLE by distance approximately equal to PME diameter. Chelicerae orange-brown, with faint black mottling; labium and endites pale orange-brown; sternum bright yellow-orange, with black mottling, brown around borders. Abdomen oval, dorsum mottled grey, with pair of comma-shaped cream patches anteriorly and pair of narrow transverse cream bands at midpoint, merging with anterior markings but separated mesally ( Fig. 215 ); five slender cream chevrons in posterior ¼ above spinnerets; two pairs of orange-brown sigilla, first pair oval, at ¼ AL, second pair elongate-oval, at midpoint of abdomen; venter uniform creamy-grey. Legs yellow-brown, I darker than others; all with faint grey mottling. Epigyne with broad, recurved oblique ridges anterolaterally in epigyne, entering shallow atrium, with short copulatory duct bending back on itself and narrowing mesally, entering racket-shaped ST II comprising proximal stalk and globose distal receptacle; connecting ducts emerging from atrium laterally, slender, converging mesally towards posterior, making lateral bend before entering bilobed ST I ( Figs 234, 235 ).

Type material. Holotype ♀: SOUTH AFRICA: Eastern Cape: Amatola mountains, Hogsback, Amatola Forestry Company offices, 32°35.276'S, 26°55.911'E, 1270 m a.s.l., 22.IV.2012, C. Haddad (active search, under overhanging vegetation) ( NCA 2014 /607).

Other material. None.

Distribution. Only known from the type locality ( Fig. 236 ).

Remark. Males and additional female specimens were collected in a canopy fogging sample from Hogsback and imaged, but these specimens seem to have been lost. The male clearly possesses a dorsal scutum, and has a far larger and more pronounced cymbial apophysis than congeners. The shape of the embolus is not dissimilar to T. tyume sp. nov., but is shorter and opposes a small distal tooth-like tegular apophysis. Description of the male requires the discovery of fresh material.

Figures

FIGURE 236. Distribution of Trachecymbius felis sp. nov. (blue circles), T. peterwebbi sp. nov. (green triangle) and T. tyume sp. nov. (yellow triangles) in southern Africa. Black star indicates Hogsback, where T. bosselaersi sp. nov., T. felis sp. nov., T. tyume sp. nov. and T. umbella sp. nov. occur sympatrically.

FIGURES 215–221. Digital microscope photographs of dorsal habitus of Trachecymbius spp. 215. T. bosselaersi sp. nov., female; 216, 217. T. felis sp. nov., male (216) and female (217); 218. T. peterwebbi sp. nov., male; 219, 220. T. tyume sp. nov., male (219) and female (220); 221. T. umbella sp. nov., female. Scale bars = 1.0 mm.

FIGURES 222–223. Trachecymbius bosselaersi sp. nov., female epigyne in ventral (222) and dorsal (223) views. Scale bars = 0.1 mm.

FIGURES 230–235. Trachecymbius tyume sp. nov., male (230, 231) and female (232, 233), and T. umbella sp. nov. female (234, 235): 230. Left palp, ventral view; 231. Same, retrolateral view; 232, 234. Epigynes, ventral view; 233, 235. Same, dorsal view. Scale bars = 0.1 mm.