Capobula, Haddad & Jin & Platnick & Booysen, 2021

Haddad, Charles R., Jin, Chi, Platnick, Norman I. & Booysen, Ruan, 2021, Capobula gen. nov., a new Afrotropical dark sac spider genus related to Orthobula Simon, 1897 (Araneae: Trachelidae), Zootaxa 4942 (1), pp. 41-71: 46-51

publication ID

https://doi.org/10.11646/zootaxa.4942.1.2

publication LSID

lsid:zoobank.org:pub:79353662-7653-4F41-8B39-40E6E4B2E005

DOI

http://doi.org/10.5281/zenodo.4596095

persistent identifier

http://treatment.plazi.org/id/03D67155-FFAA-FFAC-FF25-FC83A42228C9

treatment provided by

Plazi

scientific name

Capobula
status

gen. nov.

Genus Capobula   gen. nov.

Type species: Orthobula infima Simon, 1896a  

Diagnosis. Capobula   gen. nov. can be recognized from all other trachelid genera except Orthobula   by the combination of a large number of paired ventral spines on the anterior tibiae, metatarsi and tarsi, the absence of ventral cusps in both sexes, the deep pits on the carapace, and the presence of a large ventral sclerite on the abdomen of males. Although Spinotrachelas Haddad, 2006   and Poachelas   also have heavily spined anterior legs, both have ventral cusps on the anterior legs, lack carapace pits, and lack a ventral abdominal scutum ( Haddad 2006; Haddad & Lyle 2008). Female Capobula   gen. nov. can be recognized by the laterally positioned, teardrop-shaped primary spermathecae that are in the same transverse plane as the copulatory openings, while in Orthobula   the spermathecae are oval and positioned posteriorly, close to the midline of the epigyne, and far from the anteriorly positioned copulatory openings (e.g. Marusik et al. 2013: figs 19–22). Further, Capobula   gen. nov. lack pits along the midline of the carapace ( Figs 3–11 View FIGURES 3–10 View FIGURES 11–19 ), which are present in Orthobula   (e.g. Marusik et al. 2013: figs 1, 4; Ramírez 2014: fig. 6A). Capobula   gen. nov. can be separated from Orthobula   by the male palpal tegulum being pear-shaped and approximately as broad as the cymbium, and the embolus with a broad base, clear bend near its midpoint, and tip directed retrodistally (e.g. Fig. 52 View FIGURES 47–53 ). In Orthobula   the tegulum is subtriangular and strongly swollen basally towards the prolateral side, and the embolus usually straight, narrow, finely coiled and directed distally (e.g. Marusik et al. 2013: figs 11–16).

Etymology. The genus name is a combination of Cape, referring to the Western and Eastern Cape Provinces of South Africa from where the majority of the species have been recorded, and Orthobula   , to which it is closely related. Gender is feminine.

Description. Small spiders, 1.70–2.35 mm in total length; carapace bright orange to deep red-brown ( Figs 3–10 View FIGURES 3–10 ); carapace oval, broadest at middle of coxae II, eye region narrow, fovea indistinct, a short shallow depression ( Fig. 11 View FIGURES 11–19 ); posterior margin very slightly concave; carapace surface finely granulose, with series of deep pits forming striae, pits absent from midline of carapace ( Figs 11, 12 View FIGURES 11–19 ), each pit with central pore; surface sparsely covered with scattered fine curved setae ( Figs 12, 13 View FIGURES 11–19 ). All eyes surrounded by black rings ( Figs 3–10 View FIGURES 3–10 ); anterior eye row procurved in anterior view, recurved in dorsal view, anterior median eyes approximately ¾ anterior lateral eye diameter; anterior median eyes separated by approximately ½ their diameter, nearly touching anterior lateral eyes ( Figs 13, 14 View FIGURES 11–19 ); posterior eye row recurved in dorsal view, posterior median eyes oval, posterior lateral eyes round; posterior median eyes approximately 1¼ times posterior lateral eye diameter; MOQ narrower anteriorly than posteriorly, length and posterior width approximately equal. Chilum indistinct, a tiny transverse sclerite; cheliceral promargin and retromargin with two teeth each, cheliceral escort seta present ( Figs 15, 16 View FIGURES 11–19 ); fang with distinct serrula ( Fig. 16 View FIGURES 11–19 ); endites convergent, not sexually dimorphic, slightly notched laterally ( Fig. 17 View FIGURES 11–19 ), with distinct serrula comprising sharp, ventrally curved denticles ( Fig. 18 View FIGURES 11–19 ); dense maxillar hair tuft on mesal margins ( Fig. 17 View FIGURES 11–19 ); labium trapezoidal, slightly wider than long. Pleural bars sclerotised, isolated; sternum shield-shaped, longer than broad, surface smooth with deep pits without pores, sparsely covered in long straight setae ( Figs 19 View FIGURES 11–19 , 20 View FIGURES 20–29 ); precoxal triangles present, intercoxal sclerites present between all coxal pairs. Leg formula 4132, sparsely covered in long fine setae; femora I with mesal convex curvature, all femora strongly constricted proximally, with sparse ventral tubercles in basal half ( Figs 21, 22 View FIGURES 20–29 ); patellae with small lyriform organ on prolateral side ( Fig. 23 View FIGURES 20–29 ), patellar indentation on retrolateral side narrow, with lyriform organ at proximal end ( Figs 24, 25 View FIGURES 20–29 ); anterior legs with strong paired ventral spines on tibiae, metatarsi and tarsi ( Figs 26–29 View FIGURES 20–29 ); metatarsi IV with sparse chemosensory setae and trichobothria dorsally, ventral preening brush at distal end ( Fig. 30 View FIGURES 30–38 ); tarsi with sparse tactile hairs, few dorsal trichobothria and chemosensory setae ( Figs 31, 32 View FIGURES 30–38 ); trichobothria with sunken distal plate, distal margin of hood overlapping plate, hood with four curved ridges, roughly concentric ( Fig. 33 View FIGURES 30–38 ); tarsal organ oval, very slightly elevated from integument, surface finely wrinkled, opening oval and distally placed ( Figs 31, 34 View FIGURES 30–38 ); paired tarsal claws short, with two teeth and moderately dense tenant setae forming claw tufts in between ( Figs 35, 36 View FIGURES 30–38 ); palpal claw simple, sharply curved distally ( Fig. 37 View FIGURES 30–38 ). Abdomen oval, clearly larger in females than males, with dorsal scutum in males only; dorsum with very sparse fine setae and two pairs of sigilla, prominent in females, barely distinguishable on scutum in males ( Figs 3–10 View FIGURES 3–10 , 38 View FIGURES 30–38 ); venter without post-epigastric sclerites, with large ventral sclerite in males that is wider than long, absent in females; small, weakly sclerotized inframamillary sclerite present in females, indistinct in males. Spinnerets (observed in C. infima   comb. nov. only): female ( Figs 39, 41–43 View FIGURES 39–46 ): anterior lateral spinnerets of female each with one major ampullate gland spigot, one nubbin and approximately ten piriform gland spigots; posterior median spinnerets of female each with one small minor ampullate gland spigot and five large cylindrical gland spigots; posterior lateral spinnerets of female each with two large cylindrical gland spigots and approximately ten aciniform gland spigots; male ( Figs 40, 44–46 View FIGURES 39–46 ): anterior lateral spinnerets of male each with one major ampullate gland spigot and five piriform gland spigots; posterior median spinnerets of male each with only one minor ampullate gland spigot and one tartipore evident; posterior lateral spinnerets of male each with only a single tartipore discernible. Female epigyne with small paired copulatory openings positioned anteriorly in epigyne ( Fig. 47 View FIGURES 47–53 ), in same transverse plane as teardrop-shaped laterally positioned primary spermathecae (e.g. Figs 54 View FIGURES 54–58 , 59 View FIGURES 59–64 ); copulatory ducts directed posteriorly along midline, with membranous anterior bursae originating near initial part of ducts; posteriorly, copulatory ducts bend laterally to enter spermathecae along their mesal margin (e.g. Figs 55 View FIGURES 54–58 , 60 View FIGURES 59–64 ); secondary spermathecae not distinguished. Male palpal femur, patella and tibia all with ventral apophyses ( Figs 48–52 View FIGURES 47–53 ), patella with lyriform organ associated with apophysis ( Figs 49, 50 View FIGURES 47–53 ); tegulum pear-shaped, broadest basally, tapering distally, slightly broader than cymbium, with narrow sperm duct running down centre of tegulum in ventral view, with single basal loop (e.g. Fig. 57 View FIGURES 54–58 ); embolus distal, curving retrodistally ( Fig. 53 View FIGURES 47–53 ), tegulum without any other structures.

Composition. Capobula infima ( Simon, 1896a)   comb. nov. (type species) and four new species, C. capensis   spec. nov., C. montana   spec. nov., C. neethlingi   spec. nov. and C. ukhahlamba   spec. nov.

Distribution. Only known from South Africa and the enclave of Lesotho.