Couranga, Gray & Smith, 2008

Gray, Michael R. & Smith, Helen M., 2008, A New Subfamily of Spiders with Grate-shaped Tapeta from Australia and Papua New Guinea (Araneae: Stiphidiidae: Borralinae), Records of the Australian Museum 60 (1), pp. 13-44 : 22

Couranga n.gen.

Type species. Couranga kioloa n.sp.

Etymology. The generic name refers to a locality in Royal National Park, New South Wales, and is considered feminine in gender.

Diagnosis. Palpal cymbium with a relatively small but well-defined retrolateral flange, margin angled apically; bulb long with a pronounced basal TL; bipartite MA with membraneous to weakly sclerotized processes; processes on anterior conductor margin. RVTA with definite stalk. Epigynum divided, fossae with shallow lateral extensions. Separated from other genera by the shallow lateral extensions of the epigynal fossae; additionally, from Pillara , Borrala , Jamberoo and Asmea by the complex conductor margin, from Elleguna by the absence of a ventral conductor process, and from Karriella by the divided epigynal fossa; separated from Therlinya by the striped carapace.

Description. Medium-sized, cribellate spiders (CL 2.24–3.47); with the characters of the subfamily Borralinae . Colour (in alcohol) ( Fig. 1a,b,e,f ). Carapace amber-brown, eye region dark grey with eyes surrounded by black pigment; a pair of wide, variably pigmented dark grey stripes run midlaterally back from the eye region to coalesce and terminate at or just behind the fovea; thoracic area with narrow, dark grey, marginal stripes. Mouthparts dark brown. Legs with distinct grey-brown bands on femora and tibiae; male metatarsi and tarsi unicolorous, orange brown to light grey brown. Dorsal abdomen patterned in greyish-brown and unpigmented patches with a narrow, grey mid-dorsal anterior stripe, sometimes indistinct, and 4–5 chevrons posteriorly; lateral abdomen with a mosaic of darker and lighter patches; venter grey-brown with several more or less paired pale patches centrally and a pair of pale stripes laterally.

Carapace. Profile highest at fovea in male; in female gently arched, often flattish from mid-caput to fovea ( Fig. 1c,d ). Foveal slit moderately long and deep, curving down onto concave rear slope of carapace. Clypeus about 2× width of an AME. Cheliceral/palpal stridulatory organ absent. Eyes eight, relatively large (cf. Therlinya ); grate-shaped tapeta in posterior eyes; EGW 0.70–0.80× width of caput; AME largest or subequal to PME: AME≥PME>PLE≥ALE. MOQ almost square, slightly narrower anteriorly.

Legs. 1423. Male metatarsus II with middle to distal part weakly bowed (dorsally concave) and dorsoventrally flattened; less evident on metatarsus I. Spines: Leg tibiae with 0–2 ventral apical spines; metatarsi with distal whorl of 5 spines. Representative leg spination ( C. kioloa ): Male (KS74065)—I: femur d122, p011; tibia d0010, v221, p111, r1010; metatarsus d202, v201, p0101, r0101; II: femur d122, p0111; tibia d0010, v221, p111, r1010; metatarsus d202, v201, p0101, r0101; III: femur d122, p0111; patella d001; tibia d1010, v122, p1010, r0110; metatarsus d202, v221, p0101, r0101; IV: femur d112, p001; tibia d1010, v112, p0101, r01010; metatarsus d212, v221, p0101, r001. Female (KS74066)—I: femur d112, p011; tibia d001(small), v220, p111, r1010; metatarsus d002, v221, p0101, r0101; II: femur d122, p0111; tibia d0010, v220, p111, r1010; metatarsus d102, v221, p0101, r0101; III: femur d122, p0101; patella d101; tibia d1010, v011(111), p0101, r01010; metatarsus d202, v2021, p0101, r0101; IV: femur d112, p001; patella d001; tibia d1010, v112, p0101, r01010; metatarsus d2012, v221, p0101, r001. Three tarsal claws: superior 9–10 teeth, inferior 2–3 teeth. Female palpal tarsi spinose; palpal claw with 11–12 teeth. Trichobothria in single row of 5–6 on both tarsi and metatarsi.

Male palp ( Figs 2a–d , 6a,b ). Cymbium with a coniform apex with 3 bristle-like spines; retrolateral flange well defined, with apical margin offset at c. 90° to cymbium. Bulb much longer than wide. Tegulum with a large, basal TL, strongly offset from base of embolus. Sperm duct visible on the basal tegulum as a thick, upright S-shaped loop. T-shaped conductor with anterior margin modified (rather than uniformly curved)—prolaterally thickened with an apically notched process arising centrally, and a retrolateral “crested” spine-like conductor apex curving ventrally ( Figs 2a,b , 6a ). Embolus arising prolaterally from a wide base, curving through less than 180° as a gradually tapering rod with a single sub-distal barb and a blunt apex resting within the sub-apical conductor groove ( Fig. 2b ). Tegular window prolateral, of small to moderate size. MA bipartite: medial process small, membraneous; lateral process a thin, membraneous or weakly sclerotized lamina ( Figs 6a,b , 7a,b ). Tibia about as long as wide, with 3 strong prolateral to dorsal bristles and two distal apophyses: RVTA with a short to moderate length stalk and an ovoid, blunt, beak-like head; RDTA a thick hooked or spine-like process. Patella about as long as wide with a dorsal bristle.

Epigynum ( Fig. 6c,d ). Paired fossae separated by a moderately wide septum; fossae shallow, extended laterally and narrowed centrally (sometimes almost “dumbbell-shaped”— Fig. 7c ). Posterior to fossae a pair of low cuticular mounds overlie the spermathecae (visible through cuticle) ( Fig. 6c ). Copulatory ducts open anterolaterally adjacent to septum (fossae and openings sometimes obscured by mating plug). Internal genitalia simple, with a pair of very short, broad copulatory ducts curving back to enter the spermathecae, where they equal its width; spermathecae oblong-globose and adjacent, placed immediately behind the fossa.

Spinnerets. Cribellar plate with each field c. 3.0× as wide as long and separated by a wide seam (about 0.5× a field width). Spigots (female, KS62178): ALS: 2 MAP spigots, mesal, adjacent, unequal; c. 35 piriform spigots; PMS: 1 mAP with 2–3 fused paracribellar bases (each with c. 6 to 8 spigots) grouped anteroectally around it; 5 aciniform spigots (1 anterior, rest distributed); 1 cylindrical spigot, ectal; PLS: c. 11 aciniform spigots, distributed; 1 modified PLS spigot, subapical, flanked by 3 paracribellar spigots, all free; 2 cylindrical spigots (1 basal, 1 central).

Included species. Couranga kioloa n.sp., C. diehappy n.sp.

Remarks. These spiders are distributed from southeastern NSW to southeastern Queensland; the two species overlap widely in the central–northeastern region of NSW. Modification of the anterior conductor margin is shared with Karriella and Elleguna , although the structural details differ, especially in the latter genus. Epigynal plugs, which may fill the fossae, are frequently found in both species.

Figures

Fig.1. Couranga kioloa: a,d,f, female:(a), body, dorsal; (d,f), female carapace:d, lateral; f, frontal showing chilum.(b,c,e), male carapace: b, dorsal; c, lateral; e, frontal. Scale lines 1.0 mm: left, a–d; right, e,f.

Fig. 2. Male palps.a–d, Couranga kioloa (KS69663): (a), cymbium and bulb, ventral; (b), distal conductor and embolus (barb on subapical embolus arrowed); (c), tibia, retrolateral; (d), trichobothria on cymbium. (e–g), Karriella treenensis (KS14702): e, tibia, cymbium and bulb, ventral; f, conductor and bipartite median apophysis, proventral; g, RDTA, dorsal. (h,i), Jamberoo johnnoblei (KS8503): h, tibia, cymbium and bulb, ventral; i, bipartite MA processes, retrolateral.

Fig. 6. Couranga kioloa. (a,b), male palp (holotype): a, ventral; b, retrolateral. (c,d), epigynum: c, ventral (KS74064); d, dorsal—internal genitalia (KS69664). Scale lines 0.5 mm: upper, a,b; lower, c,d.

Fig. 7. Couranga diehappy. (a,b), male palp (holotype): a, ventral; b, retrolateral. (c–e), epigynum: c, ventral (KS75360); d, ventral, with plug (KS58105); e, dorsal—internal genitalia (KS75366). Scale line 0.5 mm.