Austrachelas Lawrence, 1938

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 : 16

Austrachelas Lawrence, 1938

Austrachelas Lawrence, 1938: 504 .

Austrachelas: Dippenaar-Schoeman & Jocqué, 1997: 128 . Type species: Austrachelas incertus Lawrence, 1938

Diagnosis. Austrachelas spiders can be recognised by a combination of the following characters: densely scopulate anterior metatarsi and tarsi; strongly spined posterior legs, with prolateral and retrolateral dorsal metatarsal spines in two rows; eyes in closely situated group, PME smaller and more closely situated to each other than to PLE; carapace raised evenly along midline, and sternum oval ( Figs 16–18 ). Female epigyna well sclerotised, with anterior hood [epigynal atrium] and lateral hoods [lateral ridges], laterally situated copulatory openings in narrow fold ( Figs 20 , 31 , 38 ), and complex internal structures; post-epigastric sclerites present in females ( Fig. 20 ). Male palps with dense setal mat in distal half of cymbium [cymbial scopula], short hook-like median apophysis present, and embolus distally curved in broad arc, with small lobed or denticulate structures on its distal margin ( Figs 29, 30 , 41 ).

Description. Medium to large sized spiders, 4.7–15.3mm in length. Carapace orange-brown to bright wine-red in colour, paler along midline ( Figs 1–15 ); carapace raised evenly along midline, sloping sharply posteriorly ( Fig. 18 ). Eyes closely grouped together; AER procurved, PER straight or very slightly recurved ( Fig. 16 ); AME closer to ALE than to each other, ALE larger than AME; PME transversely oval, flattened, closer to each other than to PLE, PME smaller than PLE ( Figs 36, 39 ). Chelicerae not protruding far beyond anterior margin of carapace; fangs long, directed obliquely ( Figs 16, 17 , 40 ), with scrappy setae close to fang base ( Fig. 28 ); lateral margins of endites nearly parallel, inner margin with distinctive groove ( Fig. 17 ); labium longer than wide. Sternum oval, narrowed anteriorly ( Figs 17 , 37 ); precoxal triangles and intercoxal sclerites present ( Fig. 17 ); pleural bars isolated ( Fig. 18 ). Leg formula 4123; trochanters not notched ( Figs 21, 22 ), patellar indentation narrow ( Fig. 23 ); anterior legs with one or two prolateral spines on femora only, metatarsi and tarsi densely scopulate ventrally ( Figs 24 , 33 ); posterior legs strongly spined, with dorsal metatarsal spines in paired prolateral and retrolateral rows ( Figs 25, 26 , 34 ); metatarsi III and IV longer than tibiae. Abdomen elongate, grey dorsally with cream chevron markings ( Figs 1–15 ), pale laterally and ventrally; males with short dorsal scutum, absent in females; dorsum with two pairs of sigilla; venter unsclerotised except for post-epigastic sclerites ( Fig. 20 ). Spinnerets (only observed with SEM in Austrachelas pondoensis n. sp., Figs 42–49 ): anterior lateral spinnerets conical, nearly cylindrical, not widely spaced, with two articles, terminal article continuous on ectal margin, interrupted mesally at major ampullate area; female with two major ampullate gland spigots, posterior one much larger (reduced to nubbin in male); piriform gland spigots relatively small, not sexually dimorphic, shafts about same size as anterior major ampullate. Posterior median spinnerets with two minor ampullate gland spigots (one reduced to nubbin in male), many aciniform gland spigots, and posterior field of 10 cylindrical gland spigots, loosely arranged in rows (absent in male). Posterior lateral spigots with many aciniform gland spigots, two basal cylindrical gland spigots (absent in male), and one distal modified spigot ( minor ampullate, sensu Platnick 2002). Colulus a pilose patch. Female epigyne with anterior and lateral hoods, lateral copulatory openings ( Figs 31 , 38 ), anterior ST 2 and posteriorly situated ST 1. Male palp with broad cymbium with dense dorsal distal setal mat, broadly curved embolus and median apophysis on tegulum ( Figs 29, 30 ); embolus sometimes with lobed or denticulate protuberance on distal margin ( Figs 29 , 41 ); male palpal tibia with complex single apophysis with variable shape, often with lobes or denticles.

Figures

FIGURES 16 – 26. Digital microscope photographs of the somatic morphology of female Austrachelas pondoensis n. sp.. (16) cephalothorax, dorsal view; (17) same, ventral view; (18) same, lateral view; (19) abdomen, dorsal view; (20) abdominal venter, epigastric area; (21) trochanter I, ventral view; (22) trochanter IV, ventral view; (23) patella I, retrolateral view; (24) leg I, prolateral view, arrow indicating metatarsal and tarsal scopulae; (25 – 26) distal end of leg IV, indicating paired retrolateral dorsal spines and metatarsal and tarsal scopulae. Abbreviations: AH – anterior epigynal hood; EG – endite groove; IS – intercoxal sclerite; LH – lateral epigynal hood; MHT – maxillar hair tuft; PB – pleural bars; PDS – paired dorsal metatarsal spines; PES – post-epigastric sclerite; PI – patellar indentation; PT – precoxal triangle; SC – scopulae; SI – sigillum; TR – trichobothria.

FIGURES 27 – 35. Scanning electron micrographs of Austrachelas pondoensis n. sp. somatic and genitalic morphology. (27) female chelicera, posterior view; (28) same, anterior view (29) male palp, ventral view; (30) same, dorsal view; (31) female epigyne, ventral view; (32) female left palp, retrolateral view, arrows indicating erect ventral setae; (33) female left leg 1, arrows indicating metatarsal and tarsal scopulae; (34) female left metatarsus 4, arrows indicating paired dorsal prolateral spines; (35) female, tarsal claw of left leg 4. Abbreviations: AH – anterior epigynal hood; CO – copulatory openings; EM – embolus; EP – embolar protuberance; LH – lateral epigynal hood; MA – median apophysis; PDS – paired dorsal metatarsal spines; PMT – promarginal teeth; RMT – retromarginal teeth; SC – scopulae; SS – scrappy seta; ST – subtegulum. Scale bars: 27, 29, 30 = 0.5 mm; 28, 31 = 0.2 mm; 32 – 34 = 1.0 mm; 35 = 0.1 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 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 42 – 49. Scanning electron micrographs of spinnerets of Austrachelas pondoensis n. sp. male (42, 44 – 46) and female (43, 47 – 49). (42, 43) spinneret arrangement; (44, 47) anterior lateral spinneret; (45, 48) posterior median spinneret; (46, 49) posterior lateral spinneret. Abbreviations: Ac – aciniform gland spigot (s); ALS – anterior lateral spinneret; Cy – cylindrical gland spigot (s); maAmp – major ampullate gland spigot (s); miAmp – minor ampullate gland spigot (s); MS – PLS modified spigot (s); nu – nubbin (s); Pi – piriform gland spigot; PLS – posterior lateral spinneret; PMS – posterior median spinneret; ta – tartipore (s). Scale bars: 42 = 0.2 mm; 43 = 0.5 mm; 44 – 47 = 0.05 mm; 48, 49 = 0.1 mm.