Austrachelas merwei, Haddad, Charles R., Lyle, Robin, Bosselaers, Jan & Ramirez, Martin J., 2009

Haddad, Charles R., Lyle, Robin, Bosselaers, Jan & Ramirez, Martin J., 2009, A revision of the endemic South African spider genus Austrachelas, with its transfer to the Gallieniellidae (Arachnida: Araneae), Zootaxa 2296, pp. 1-38 : 20-21

Austrachelas merwei n. sp.

( Figs 5, 6 , 36–41 , 60–63 )

Diagnosis. Females of this species are recognised by the broad tongue-like anterior hood of the epigyne ( Fig. 60 ), and males by the narrow RTA of the palp with a curved tip, and the distal margin of the embolus, with a single prolateral process ( Figs 41 , 62 ).

Etymology. Named for Marius van der Merwe, who collected all the known material of this species.

Female. Measurements: CL 2.15–3.17, CW 1.63–2.33, FL 0.18–0.33, AL 2.95–5.48, AW 1.60–2.75, SL 1.30–1.83, SW 1.05–1.30, TL 5.35–9.10, AME–AME 0.05, AME–ALE 0.04, ALE–ALE 0.29, PME–PME 0.07, PME–PLE 0.10, PLE–PLE 0.45.

Length of leg segments (sequence from femur to tarsus, and total): I 2.20 + 1.23 + 1.60 + 1.23 + 0.78 = 7.04; II 2.03 + 1.18 + 1.47 + 1.18 + 0.78 = 6.64; III 1.80 + 0.95 + 1.05 + 1.40 + 0.65 = 5.85; IV 2.40 + 1.25 + 1.87 + 2.03 + 0.93 = 8.48.

Carapace deep orange-brown, slightly paler along midline ( Fig. 5 ); AER procurved, laterals slightly larger than medians; AME separated by distance equal to ½ their diameter, AME separated from ALE by distance equal to ½ AME diameter; clypeus height equal to 1¼ AME diameter at AME, equal to ½ ALE diameter at ALE; PER very slightly recurved, nearly straight, laterals larger than medians ( Fig. 36 ); PME separated by distance equal to ¾ their diameter, PME separated from PLE by distance equal to PME diameter. Chelicerae deep orange-brown; promargin with four teeth, second tooth largest, remaining teeth subequal in size; proximal and second teeth close together, separate from closely situated third and fourth teeth by small gap; retromargin with single small denticle, situated near third promarginal tooth. Legs all orange in colour, slightly darker distally. Leg spination: femora: I pl 1 do 1, II pl 1–2 do 1, III pl 2 do 2 rl 1, IV do 2 rl 1; patellae: spineless; tibiae: I & II spineless, III pl 2 rl 2 plv 2 rlv 1 vt 2, IV pl 2 rl 2 plv 2 rlv 2 vt 2; metatarsi: I & II spineless, strongly scopulate, III & IV scopulate in distal half, III pl 5 rl 4 plv 1 rlv 1 vt 2, IV pl 6 rl 5 plv 2 rlv 2 vt 2; palp: femora do 2, patellae pl 1, tibiae pl 2 rl 2, tarsus pl 3 do 1 rl 2 plv 1 rlv 1. Abdomen pale grey dorsally, with mottled pale grey chevron ( Fig. 5 ), cream laterally and ventrally; dorsum and venter lacking scutum or other sclerites. Female epigyne with distinctive lateral hoods and tongue-like anterior hood ( Figs 38 , 60 ); copulatory openings anterolaterally situated, entering ST 2 via narrow entrance ducts; ST 2 anteriorly situated, oval with lateral oval expansions, with looping tube leading to large posteriorly situated ST 1 ( Fig. 61 ).

Male. Measurements: CL 2.48–3.05, CW 1.83–2.23, FL 0.23–0.28, AL 3.20–3.65, AW 1.68–1.95, SL 1.43–1.57, SW 1.05–1.15, TL 5.80–6.83, AME–AME 0.06, AME–ALE 0.03, ALE–ALE 0.30, PME–PME 0.07, PME–PLE 0.09, PLE–PLE 0.47.

Length of leg segments (sequence from femur to tarsus, and total): I 2.30 + 1.23 + 1.78 + 1.18 + 0.87 = 7.36; II 2.13 + 1.15 + 1.60 + 1.28 + 0.90 = 7.06; III 1.78 + 0.90 + 1.10 + 1.43 + 0.73 = 5.94; IV 2.43 + 1.15 + 1.78 + 2.13 + 0.93 = 8.42.

Carapace uniform orange-brown, slightly paler along midline ( Fig. 6 ); AER strongly procurved, laterals slightly larger than medians; AME separated by distance equal to ½ their diameter, separated from ALE by distance equal to ¼ AME diameter; clypeus height equal to AME diameter at AME, equal to ¾ ALE diameter at ALE; PER very slightly recurved, nearly straight, laterals larger than medians ( Fig. 39 ); PME separated by distance equal to ½ their diameter, PME separated from PLE by distance equal to PME diameter. Chelicerae deep orange-brown; promargin with four teeth, proximal tooth smallest, second tooth largest, third and fourth teeth progressively smaller; retromargin with one small denticle, situated near third promarginal tooth. Legs all deep orange, paler yellow-orange distally. Leg spination: femora: I pl 1 do 1, II pl 1 do 1, III pl 3 do 2 rl 2, IV do 2; patellae: spineless; tibiae: I & II spineless, III pl 2 rl 2 plv 2 rlv 1 vt 2, IV pl 2 rl 2 plv 2–3 rlv 2 vt 2; metatarsi: I & II spineless, strongly scopulate, III & IV scopulate in distal half, III pl 5 rl 4 plv 1 rlv 1 vt 2, IV pl 6 rl 5 plv 2 rlv 1 vt 2. Abdomen grey with indistinct pale grey chevron dorsally ( Fig. 6 ), cream laterally and ventrally; dorsum with small anterior scutum, venter without sclerites. Male palpal tibia with single triangular retrolateral apophysis with curved tip; median tegular apophysis broad, hook-like; embolus arc-shaped, with distinct distal angle, and single tooth-like prolateral embolar process ( Figs 41 , 62, 63 ); palpal spination: femora do 2.

Type material: Holotype Ƥ: SOUTH AFRICA: KwaZulu-Natal Province, Ngome State Forest, 27°49'S, 31°26'E, VIII.1992, M. van der Merwe (pitfall traps, dense forest) (NCA 94/448). Allotype 3: same locality as Holotype, XII.1992, M. van der Merwe (pitfall traps, open forest) (NCA 94/398).

Paratypes: All from type locality, collected by M. van der Merwe using pitfall traps: Dense forest: III.1992, 13 (NCA 94/418); V.1992, 13 (NCA 94/411); V.1992, 13 (NCA 94/434); V.1992, 33 (NCA 94/ 446); VI.1992, 13 (NCA 94/397); VI.1992, 13 (NCA 94/419); XII.1992, 1 Ƥ (NCA 94/405); Open forest: III.1992, 23 (NCA 94/423); IV.1992, 33 (NCA 94/427); IV.1992, 43 (NCA 94/429); IV.1992, 1 Ƥ (NCA 2005/2033); V.1992, 13 (NCA 94/409); V.1992, 33 (NCA 94/428); VI.1992, 13 (NCA 94/44); VI.1992, 13 (NCA 94/400); VII.1992, 1 Ƥ (NCA 94/435); IX.1992, 1 Ƥ (NCA 94/447); X.1992, 1 Ƥ (NCA 94/403); X.1992, 1 Ƥ (NCA 94/444); X.1992, 13 (NCA 94/432); XI.1992, 1 Ƥ (NCA 94/399); XI.1992, 1 Ƥ (NCA 94/ 417); XII.1992, 1 Ƥ (NCA 94/424).

Distribution. Known only from the type locality ( Fig. 82 ).

Figures

FIGURE 82. Distribution of the genus Austrachelas, endemic to South Africa.

FIGURES 1 – 15. Digital microscope photographs of the habitus of Austrachelas species: (1) A. bergi n. sp., female; (2) A. incertus Lawrence, 1938, female; (3) same, male; (4) A. kalaharinus n. sp., male; (5) A. merwei n. sp., female; (6) same, male; (7) A. natalensis Lawrence, 1942, female; (8) same, male; (9) A. pondoensis n. sp., female; (10) same, male; (11) A. reavelli n. sp., female; (12) same, male; (13) A. sexoculata n. sp., male; (14) A. wassenaari n. sp., female; (15) same, male. Scale bars = 2.0 mm.

FIGURES 36 – 41. Scanning electronic micrographs of Austrachelas merwei n. sp. female (36 – 38) and male (39 – 41). (36, 39) eye structure and arrangement, dorsal view; (37) sternum; (38) epigyne, ventral view; (40) mouthparts; (41) distal half of male palpal tegulum. Abbreviations: AH – anterior epigynal hood; CO – copulatory openings; EM – embolus; EP – embolar protuberance; LH – lateral epigynal hood; MA – median apophysis.

FIGURES 60 – 67. Genitalic morphology of Austrachelas species. (60 – 63) A. merwei n. sp.: female epigyne, ventral view (60), dorsal view (61), male palp, ventral view (62), retrolateral view (63); (64 – 67) A. natalensis Lawrence, 1942: female epigyne, ventral view (64), dorsal view (65), male palp, ventral view (66), retrolateral view (67). Scale bars = 0.1 mm.