Afroceto rotunda, 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 : 365-368

Afroceto rotunda sp. n.

Figs 19, 20 , 106–110

Etymology: From Latin rotunda (rounded); refers to the rounded anterior hood of the female epigyne.

Diagnosis: The male of this species resembles A. gracilis sp. n. in genitalic morphology, but can be distinguished by the single loop of the U­shaped seminal ducts, the presence of a ventral distal cymbial spine, and the broader, shorter retrolateral tibial apophysis ( Figs 107, 108 ). The female resembles A. arca sp. n. in genitalic morphology but can be recognised by the round anterior hood with lateral extensions leading to the copulatory openings, and the absence of a transverse duct linking the ST I ( Fig. 109 ).

Description:

Male.

Measurements: CL 2.58, CW 1.83, AL 1.41, AW 0.94, TL 3.99, FL 0.25, SL 1.49, SW 1.24, AME–AME 0.10, AME–ALE 0.06,ALE–ALE 0.45, PME–PME 0.14, PME–PLE 0.18, PLE–PLE 0.71. Length of leg segments (sequence from femur to tarsus, and total): I 2.38+1.08+1.92+1.38+0.88=7.64; II 2.00+0.92+1.62+1.27+0.85=6.66; III 1.23+ 0.65+0.96+1.23+0.46=4.53; IV 1.81+0.77+1.54+1.73+0.54=6.39.

Carapace reddish brown, pale orange posterior to midpoint ( Fig. 19 ); highest point in first third of CL, declining gradually in last two thirds; surface smooth, covered in fine setae; fovea distinct, slightly thickened, at two thirds CL. Ocular region reddish brown with dark brown rings around eyes; AER recurved, AME and ALE subequal in size; clypeus height equal to AME diameter;AME separated by distance equal to 0.84 their diameter; AME separated from ALE by 0.5 AME diameter; PER very slightly recurved, PLE subequal to PME; PME separated by distance equal to their diameter; PME separated from PLE by distance equal to 1.14 PME diameter. Chelicerae brown, slightly darker towards fang base; anterior surface with scattered black setae; two promarginal teeth, proximal tooth largest; two retromarginal teeth, proximal tooth largest. Sternum orange, border brown; surface with scattered long brown setae. Abdomen creamy pale yellow with grey mottling, with dark grey lateral line extending length of abdomen; abdomen broader anteriorly, tapering posteriorly; brown scutum covering entire dorsum; surface smooth, with short, fine setae throughout; venter cream. Legs I to IV uniform pale brown; anterior legs more robust, slightly darker than posteriors; legs with relatively dense scopulae ventrally on metatarsi and tarsi; remaining segments covered in scattered fine setae; leg spines and cusps present. Leg spination: femora: I pl 4, II pl 4; patellae spineless; tibiae: I plv 7 rlv 4 vt 2 cusps, II plv 5 cusps, III pl 1 plv 2 vt 1, IV plv 2 vt 2; metatarsi: I plv 10 rlv 7 vt 1 cusps, II plv 9 rlv 4 vt 1 cusps, III pl 1 rl 1 plv 3, IV pl 1 plv 3; tarsi: I plv 6 rlv 4 cusps, II plv 4 rlv 3 cusps ( Fig. 106 ). Palp brown; sperm duct U­shaped, narrowing towards embolus; embolus originating prolaterally, with narrow, sharply pointed tip directed obliquely towards the retrolateral margin of cymbium; cymbium with one strong prolateral distal ventral spine ( Fig. 107 ); retrolateral tibial apophysis broad, triangular, ending in sharp point ( Fig. 108 ).

Female.

Measurements: CL 2.54, CW 2.00, AL 3.46, AW 1.92, TL 6.00, FL 0.23, SL 1.47, SW 1.25,AME–AME 0.12, AME–ALE 0.06,ALE–ALE 0.45, PME–PME 0.14, PME–PLE 0.16, PLE–PLE 0.69. Length of leg segments (sequence from femur to tarsus, and total): I 2.06+0.98+1.55+1.27+0.84=6.70; II 1.86+0.88+1.39+1.20+0.78=6.11; III 1.27+0.76+ 0.98+1.18+0.47=4.66; IV 1.98+0.78+1.59+1.86+0.56=6.77.

Carapace reddish brown, pale orange posterior to midpoint ( Fig. 19 ); highest point in first third CL, with gradual decline in last two thirds; surface finely granulated, covered in short fine setae; fovea short, distinct, at two thirds CL. Ocular region reddish brown, with black rings around eyes; AER slightly recurved, AME subequal to ALE; clypeus height equal to AME diameter; AME separated by distance equal to their diameter, AME separated from ALE by distance equal to half AME diameter; PER recurved, PME subequal to PLE; PME separated by distance equal to their diameter; PME separated from PLE by 1.17 PME diameter. Chelicerae brown, darker towards fang base; dark long setae on anterior surface, increasing in length towards fang base; three promarginal teeth, median tooth largest, distal tooth smallest; two retromarginal teeth, distal tooth largest. Sternum orange, brown towards borders; surface with scattered long and short dark setae. Abdomen pale yellow with pale mottled grey; abdomen broader anteriorly, tapering posteriorly; surface smooth, covered with short fine setae throughout; venter cream. Legs I to IV uniform pale brown; metatarsi and tarsi with dense ventral scopulae, remaining segments covered with fine, scattered setae. Leg spination: femora: I pl 4, II pl 1; patellae spineless; tibiae: III pl 1 rl 1 plv 4, IV vt 2; metatarsi: III pl 1 plv 1 rlv 1, IV rlv 2. Epigyne sclerotised, with rounded anterior hood, extending laterally to medially situated copulatory openings ( Fig. 109 ); ST II approximately subequal to ST I, both spherical; ST II anterior of copulatory opening, linked by short, broad, curved duct to lateral ST I, posterior to copulatory opening ( Fig. 110 ).

Holotype ♂ and Allotype ♀: SOUTH AFRICA: Northern Cape: “Blesfontein” Farm, nr Sutherland , 32°28.087'S: 20°25.113'E, 1357 m, 30 xi.2008, V. Butler, active search, vlei [wetland] area ( NCA, 2008/2899). Distribution: Known only from the type locality ( Fig. 117 ) .

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 106–110. Afroceto rotunda sp. n. male (106–108) and female (109, 110): (106) schematic representation of cusp arrangement on legs I and II; (107) left palp,ventral view; (108) left palp, retrolateral view; (109) dissected epigyne, ventral view; (110) vulva, dorsal view. Scale bars (107–110) = 0.1 mm.

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