Parabomis Kulczyński, 1901

Dippenaar-Schoeman, Anna S. & Foord, Stefan H., 2020, Revision of the Afrotropical crab-spider genus Parabomis Kulczyński, 1901 (Araneae: Thomisidae), Zootaxa 4899 (1), pp. 161-174 : 162-163

Parabomis Kulczyński, 1901

Parabomis Kulczyński, 1901: 3 , 30, figs 25–27; Simon 1903: 1011; Lessert 1919: 181; Ono 1988: 207; Dippenaar-Schoeman 2014: 244.

Type species. Parabomis levanderi Kulczyński, 1901 .

Diagnosis. Parabomis shares with the other four African genera of the Bominae the globular body shape, small size and very short legs without spines. They share with Thomisops and Holopelus the peg-like setae on the promargins of the chelicerae, which are absent in Avelis and Felsina . It can be distinguished from Avelis , Thomisops and Holopelus by the high carapace (carapace height> carapace length), the very broad sloping clypeus, as well as the eyes that are grouped far apart,> 0.6 × clypeus width ( Fig. 1 ). Parabomis male palps differ from those of the other African genera in having both a ventral apophysis and strongly developed retrolateral apophysis on the tibia. The marginally sclerotized atrium of Parabomis differs from Holopelus and Thomisops in the absence of a hood, and from Avelis in the absence of a median septum.

Description. Female. Total length varies between 3.1–3.6 mm. Carapace cream to brown, sometimes tinted with green ( Fig. 3 ), frequently mottled with white in eye region and on clypeus, with darker patches laterally, as seen in live specimens ( Figs 1–3 ). Carapace as wide as long, anteriorly only slightly narrower than posteriorly; thoracic region high and convex, with distinct posterior declivity; declivity edge with semicircular carina with row of polyp-like tubercles, each bearing a short club-shaped seta; integument granulose, with scattered small tubercles, bearing very short, thick, flat-lying setae, more numerous laterally (very distinct in P. pilosus sp. nov. ( Fig. 1 )). Eyes small; both eye rows recurved, with AER shorter than PER and strongly recurved; lateral eyes on small tubercles, with posterior tubercle slightly larger than anterior tubercle; AME closer to ALE than to each other; ALE same size as AME; PME closer to PLE than to each; PME slightly smaller than PLE; MOQ much wider than long, slightly wider anteriorly than posteriorly. Clypeus distinct, strongly sloping, protruding slightly over cheliceral base; edge curved. Chelicerae flattened anteriorly; promargin bearing densely packed bristle-like setae. Labium longer than wide. Sternum cream to dark; narrow-oval, prolonged posteriorly to form an obtuse point between legs IV; integument granulose. Legs same color as carapace, varying from cream to pale brown, in some species mottled with white, with articulation areas of each leg segment frequently with distinct white rims; legs short and thick; patellae nearly as long as metatarsi; tibiae longer than metatarsi; macro-setae absent, legs bearing short hair-like setae; tarsi with numerous teeth on paired claw; metatarsi and tarsi in some species with strong erect setae ventrally. Abdomen creamish white to brown, with darker hue in dorsal depressions ( Figs 1–3 ); rounded, wider than long; shape varying from ball-shaped (when swollen with food or eggs) ( Fig. 17 ) to slightly flattened, with lateral and transverse striae sometimes forming deep depressions; striae bearing small tubercles, each with translucent club-shaped seta; abdomen closely pressed against cephalothorax, fitting into posterior declivity; ventral region pale. Epigyne with marginally sclerotized atrium, of which shape varies from sub-oval, triangular to bell-shaped; spermathecae simple, longer than wide, bilobed sac-like structures, short, simple copulatory ducts, with intromittent orifices uncovered and situated in anterior part.

Male: Total length varies between 1.7–2.03 mm. Males resemble females but differ as follows: smaller in size; carapace and legs darker than female, usually uniformly brown; abdomen dorsum darker, shield-like in appearance, white laterally; dorsal depressions dark; legs slightly more slender than females; tibiae, metatarsi and tarsi bearing long dense setae ventrally. Palp: femur and patella not modified; tibia with two apophyses, VTA smaller than RTA, both fused; RTA about same length as tibia, apex pointed; shape varying between species; cymbium as long as wide, tutaculum absent; tegulum round, lacking apophyses; embolus filiform at tip, originating at 9h00 position.

Distribution. Parabomis is endemic to the Afrotropical Region and was previously known from Bioko Island ( Fernando Poo), Cameroon, Eritrea, Equatorial Guinea ( Spanish Guinea), Namibia and Tanzania. New records: Botswana, Ghana, Guinea, Kenya, Malawi, Nigeria, Rwanda, South Africa, Zanzibar and Zimbabwe.

Figures

FIGURES 1–3. Habitus of live Parabomis spp. 1–2 P. pilosus sp. nov., female; 3 P. martini Lessert, 1919, female. 1–2 courtesy of J. Wilkinson; 3 courtesy of L. Wiese.

FIGURES 15–20. Parabomis megae sp. nov. 15 Male habitus, dorsal view; 16 Female habitus, dorsal view; 17 Female habitus, dorsal view; 18 Left palp, ventral view; 19 Epigyne, ventral view; 20 Epigyne, dorsal view. Scales: 1 mm.