Afroceto spicula, Lyle & Haddad, 2010

Lyle, Robin & Haddad, Charles R., 2010, A revision of the tracheline sac spider genus Cetonana Strand, 1929 in the Afrotropical Region, with descriptions of two new genera (Araneae Corinnidae), African Invertebrates 51 (2), pp. 321-321 : 368-372

Afroceto spicula sp. n.

Figs 21, 22 , 111–116

Etymology: From Latin spiculum (a dart, an arrow), which refers to the sharp embolus tip of the male.

Diagnosis: Males can easily be recognised by the sharp transverse embolus, the prominent, sharply pointed dorsal tibial apophysis, and the small, dorsally situated retrolateral patellar apophysis that is slightly curved into a point ( Figs 112, 113 ). The female has long coiled copulatory ducts and anterior ST II, leading via a fine duct to the small round posterior ST I ( Fig. 115 ).

Description:

Male.

Measurements: CL 1.90, CW 1.73, AL 2.00, AW 1.33, TL 4.00, FL 0.23, SL 1.23, SW 1.08, AME–AME 0.08, AME–ALE 0.03, ALE–ALE 0.38, PME–PME 0.10, PME–PLE 0.10, PLE–PLE 0.58. Length of leg segments (sequence from femur to tarsus, and total): I 1.70+0.78+1.35+1.15+0.78=5.76; II 1.58+0.78+1.25+1.10+0.75=5.46; III 1.10+0.55+ 0.83+0.95+0.45=3.88; IV 1.63+0.70+1.33+1.45+0.53=5.64.

Carapace light brown, pale orange posterior to fovea ( Fig. 21 ); carapace highest at eye region, first two thirds of carapace with gradual decline, with relatively steep decline in the last third; surface smooth, covered in fine setae; fovea short, distinct, at two thirds CL. Ocular region orange, with dark brown rings around eyes; AER almost straight, AME and ALE subequal in size; clypeus height equal to AME diameter; AME separated by distance equal to 0.75 their diameter; AME separated from ALE by distance equal to half AME diameter; PER slightly recurved, PLE slightly larger than PME; PME separated by 0.8 PME diameter; PME separated from PLE by 0.8 PME diameter. Chelicerae orange to brown, slightly darker towards fang base; anterior surface with scattered black setae; two promarginal teeth, proximal tooth largest; one small retromarginal tooth, situated distally. Sternum pale yellow, border light brown; surface with scattered long brown setae. Abdomen creamy pale yellow, mottled grey posterior to midpoint; abdomen broader anteriorly, tapering posteriorly; scutum nearly covering entire dorsum; surface smooth with short, fine setae throughout; venter cream. Legs I to IV uniform pale yellow; anterior legs more robust than posteriors; legs with dense scopulae ventrally on metatarsi and tarsi; remaining segments covered in scattered dark setae; leg spines and cusps present. Leg spination: femora: I pl 3, II pl 1; patellae spineless; tibiae: I plv 1 cusp, III plv 1 vt 1, IV vt 1; metatarsi: I plv 7 rlv 3 cusps, II plv 3 rlv 1 cusps, III pl 1 plv 2, IV pl 1 rl 1 plv 2 rlv 1; tarsi: I plv 6 rlv 3 cusps, II plv 2 rlv 1 cusps ( Fig. 111 ). Palp yellow; embolus with sharply pointed tip, curving transversely across cymbium to retrolateral margin; sperm duct U­shaped, narrowing towards embolus; tibial apophysis dorsally situated, slightly curved, ending in sharp point; patella with small, slightly curved dorsal apophysis ( Figs 112, 113 ).

Female.

Measurements: CL 2.30, CW 1.98, AL 3.40, AW 2.20, TL 5.80, FL 0.23, SL 1.40, SW 1.18, AME–AME 0.10, AME–ALE 0.03, ALE–ALE 0.43, PME–PME 0.15, PME–PLE 0.15, PLE–PLE 0.65. Length of leg segments (sequence from femur to tarsus, and total): I 2.45+1.03+1.98+1.68+1.20=8.34; II 2.08+0.85+1.58+1.50+1.08=7.09; III 1.53+0.80+ 1.18+1.35+0.63=5.49; IV 2.40+0.98+2.05+2.28+0.88=8.59.

Carapace dark brown ( Fig. 22 ); first two thirds of carapace rounded, with relatively steep decline in last third; surface smooth, covered in short fine setae; fovea short, distinct, at two thirds CL. Ocular region dark brown with black rings around eyes; AER slightly procurved, AME larger than ALE; clypeus height slightly less than AME diameter;AME separated by distance equal to their diameter, AME separated from ALE by 0.4 AME diameter; PER very slightly recurved, PME larger than PLE; PME separated by distance equal to their diameter; PME separated from PLE by 1.2 PME diameter. Chelicerae brown, darker towards fang base; dark long setae on anterior surface, increasing in length towards fang base; two promarginal teeth, distal tooth largest; two retromarginal teeth, proximal tooth largest. Sternum orange, brown towards borders; long, surface with scattered long dark setae. Abdomen pale yellow with chevron markings, with grey median line, light grey transverse branches and dark grey lines laterally; abdomen broader anteriorly, tapering posteriorly; surface smooth, covered with short fine setae throughout; venter cream. Legs I to IV uniform light brown, with distinct incomplete bands on femora to tibiae and complete bands on distal ends of metatarsi; dense scopulae on metatarsi and tarsi, remaining segments covered with fine, scattered setae; femora with one large incomplete proximal band; patellae with one incomplete proximal band; tibiae with two incomplete bands, proximal and distally situated. Leg spination: femora: I pl 1; patellae spineless; tibiae: III rl 1 plv 2 rlv 2 vt 2, IV pl 1 rl 2 plv 2; metatarsi: III pl 1 plv 2 rlv 2. Palpal spination: femora rlv 2, tibiae do 1. Epigyne sclerotised with semi­circular hoods, covering copulatory openings; entrance ducts coiled, ST II hidden behind hoods; ST I small, globose, posteromedially situated, linked to ST II by long narrow duct ( Figs 114–116 ); anterior portion of spermathecal structures hidden in abdomen in ventral view ( Fig. 114 ).

Holotype: ♂ SOUTH AFRICA: Northern Cape: Oorlogskloof Nat.Res., near Nieuwoudtville [31.4°S: 19.1°E], 21 xii.2000, J. Leroy, sifted from leaf litter under Rhus lancea trees, riverine thickets ( NCA, 2006/1529).

Allotype: ♀ SOUTHAFRICA: Northern Cape: 30 km SE of Britstown,“De Put” Farm , 30°48.433'S: 23°40.600'E, 20–29.i.2006, M. Burger, M. Carstens, K. Jacobs & A. Pretorius, caught in pitfall and funnel traps, SARCA (Grid trap) ( NCA, 2006/1555).

Distribution: Known from the Northern Cape Province, South Africa ( Fig. 117 ).

Genus Patelloceto gen. n.

Etymology: The name is a combination of the patella, referring to the large retrolateral patellar apophysis of the males (longer than the palpal patella), and Cetonana , to which the new genus is related. Gender feminine.

Type species: Patelloceto secutor sp. n.

Diagnosis: This genus superficially resembles Afroceto gen. n. and the South American genus Trachelopachys Simon, 1897 , but can easily be recognised by the unique genitalic morphology: males have a distal femoral apophysis that is sometimes denticulate, a large retrolateral patellar apophysis that is longer than the patella itself, and a large dorsal triangular tibial apophysis. Females can be recognised by the broad membranous median septum separating the small lateral spermathecae, and the long oblique lateral epigynal hoods flanking the copulatory openings.

Description: Medium sized spiders, 3.4–8.1 mm in length; male smaller, more robustly built than female, with legs and abdomen thicker and more compact than female. Carapace convex, highest immediately posterior to eye region; ocular region narrowest, broader medially and concave posteriorly; carapace bright orange to red­brown; carapace covered in fine setae; fovea short, distinct and slightly thickened; ocular region darkened with dark rings around eyes. Anterior eye row slightly recurved; posterior eye row recurved. Chelicerae usually with two or three promarginal teeth, and two retromarginal teeth; labium usually longer than broad; endites straight along lateral margin, serulla distinct. Sternum shield-shaped, longer than broad; short and/or long fine setae scattered across smooth surface; colouration pale yellow to orange brown, darker towards border. Legs with paired tarsal claws situated between a dense claw tuft; ventral cusps present on anterior tibiae, metatarsi and tarsi of males only, absent in females; cusps shape usually elongate with sharply rounded point ( Fig. 129 ); cusp arrangement differs between species and individuals; leg spines present, one prolateral spine on femur I, sometimes found on other femora of remaining legs; limited number of scattered spines on posterior legs, especially when compared with the genus Afroceto ; legs I to IV generally pale yellow to light brown, femora of all legs often darker than other leg segments. Abdomen broader anteriorly and tapering posteriorly; integument pale yellow to cream, with paired sigilla; males have large scutum covering abdomen dorsally, scutum in females reduced in size, usually only covering first fifth of abdomen. Female epigyne analogous structures, long oblique lateral epigynal hoods ( Fig. 131 ) that flank small copulatory openings; small, lateral ST separated by a broad membranous median septum; distance between ST varies among species ( Figs 136 , 144 ); ST I large, situated posteriorly to ST II ( Figs 137 , 145 ). Male palps with limited variation in structures; distal femoral apophysis present, but varying in size between species; retrolateral patellar apophysis is longer than the patella, extending to or past tegulum base ( Figs 135 , 140 , 143 ); triangular tibial apophysis dorsally situated, varying is size; embolus short, with two­three spines situated near embolus tip ( Figs 134 , 139 , 142 ).

Species included: P. denticulata , P. media and P. secutor (all new).

Figures

Figs 1–22. General appearance of Afroceto gen. n. species: A. martini (Simon, 1897) comb. n. female (1) and male (2); A. arca sp. n. female (3) and male (4); A. bulla sp. n. female (5); A. bisulca male (6); A. capensis sp. n. female (7) and male (8); A. coenosa (Simon, 1897) comb. n. female (9); A. corcula sp. n. female (10); A. croeseri sp. n. female (11) and male (12); A. flabella sp. n. male (13) and female (14); A. gracilis sp. n. male (15); A. plana sp. n. male (16) and female (17); A. porrecta sp. n. male (18); A. rotunda sp. n. male (19) and female (20); A. spicula sp. n. male (21) and female (22).

Figs 111–116.Afroceto spicula sp.n.male (111–113) and female (114–116): (111) schematic representation of cusp arrangement on legs I and II; (112) left palp, ventral view; (113) left palp, retrolateral view; (114) undissected epigyne,ventral view; (115) dissected epigyne,ventral view; (116) vulva, dorsal view. Scale bars (112–116) = 0.1 mm.

Fig. 117. Distribution of Afroceto rontunda sp. n. and A. spicula sp. n. in South Africa.

Figs 123–131. Scanning electron micrographs of Patelloceto secutor sp. n. male (123–130) and female (131): (123) tibia I, cusp arrangement; (124) metatarsus I, cusp arrangement; (125) tarsus I, cusp arrangement;(126) tibia II, cusp arrangement; (127) metatarsus II, cusp arrangement; (128) tarsus II, cusp arrangement;(129) individual leg cusp on tibia II; (130) right palp, prolateral view; (131) epigyne, ventral view.

Figs 132–137. Patelloceto secutor sp. n. male (132–135) and female (136–137): (132) schematic representation on cusp arrangement on legs I and II; (133) left palp, prolateral view; (134) left palp, ventral view; (135) left palp, retrolateral view; (136) epigyne, ventral view; (137) vulva, dorsal view. Scale bars (133–137) = 0.1 mm.

Figs 141–145.Patelloceto media sp. n. male (141–143) and female (144–145): (141) schematic representation on cusp arrangement on legs I and II; (142)left palp, ventral view; (143) left palp, retrolateral view; (144) epigyne, ventral view; (145) vulva, dorsal view. Scale bars (142–145) = 0.1 mm.

Figs 138–140. Patelloceto denticulata sp. n. male: (138) schematic representation of cusp arrangement on legs I and II; (139) left palp, ventral view; (140) left palp, retrolateral view. Scale bar (139, 140) = 0.1 mm.