Nyssus avidus ( Thorell, 1881 ), 2015

Raven, Robert J., 2015, & lt; strong & gt; A revision of ant-mimicking spiders of the family Corinnidae (Araneae) in the Western Pacific & lt; / strong & gt;, Zootaxa 3958 (1), pp. 1-258 : 148-150

Nyssus avidus ( Thorell, 1881) , new combination

( Figs 79d , 82a–d . Map 43)

Anchognatha avida Thorell, 1881: 229 .

Material. Queensland: holotype ♀, Somerset , Cape York, L.M. D'Albertis, MCG. Non-type material . Queensland: 2♂, Thursday I, Torres Strait, 10°48'S, 142°13'E, 25 Jan 1992, QM S32159, S46008 ; 1♀, same data but, 30 Mar–15 Jun 1996, A. von Berkey, QM S53444 ; 1♂ 1♀, Steve Irwin Wildlife Reserve , Coolabah camp, 12°32'09”S, 142°12'43”E, vehicle vibration, 13–14 Sept 2013, R. Raven, B. Baehr, QM S97458 ; 1♂, same data but 13 Sep 2013, B. Baehr, R. Raven, QM S97459 .

Diagnosis. Unlike N. albopunctatus and similar species, males and females have the radial pattern of hairs on the carapace ( Fig. 79d ) and differ from males of N. yuggera sp. nov. in the strong paracymbial spine ( Fig. 82b ) and from females in the large spermathecal head ( Fig. 82d ); females further differ from those of N. albopunctatus in the much smaller CO ( Fig. 82c ).

Description Male QM S32159

Carapace 3.36 long, 2.67 wide. Abdomen 3.68 long, 2.32 wide. Total length 7.1.

Colour: carapace dark brown with narrow bands of white feathery hairs along caput edge, and irregularly along interstrial ridges; abdomen dorsally with dark red brown scute covered with two paired large spots of white hair anteriorly discernible, with black feathery hairs to about two-thirds length, then wide lunate zone of yellow hairs with terminal narrow lobe and flanked by dark bands. Legs with brown-orange coxae, otherwise dark red brown; ventral scute and genital scute red brown; flanks gray brown. Patches of white hair laterally on abdomen, two per side and one pair anteriorly. Eyes: of front row much smaller than of back; PME within 0.3 of diameter of PLE and ca. one diameter apart. Legs: trochanter IV clearly notched; I–III with very shallow notches. Femora III and IV with distinct predistal constriction and IV also with raised area before basal spine. Spines: I: fe p1d1 basal pa 0; ti v2.2 all weak; me v2.2. II: fe p1d3r1; pa 0; ti v 1.1w; me v2.2. III: fe p1d3r2; pa r1 strong; ti p2r2v2.2.2; me p3r2v2.2.3. IV: fe p1d3r1; pa r1; strong ti p2d1r2v2.2.2; me p3r3v2.2.2. Palp: fe p1d2r1; pa p1; ti p2; cymbium p2. Abdomen: dorsal scute for anterior two-thirds; genital scute with rounded post epigastric sclerites, large rhomboidal ventral scute separated from teat-like tracheal scute. Palp: basal haematodocha expanded; femur distally incrassate; cymbium with small distinct thumb-like paracymbial spine; bulb large, constricting to narrow neck with distal flared collar before twisted tapering embolus; cymbial apex pallid with 3–4 short thick setae.

Female QM S53444

Carapace 3.08 long, 2.28 wide. Abdomen 3.83 long, 2.57 wide. Totally, 7.7.

Colour: carapace red brown and slightly rugose with fine silver hairs, mostly rubbed, in striae; legs orange brown; abdomen light brown with small triangular scute just extending over surface. Eyes: all similar in size. Chelicerae: 3P, 2R; low fang mound with 5–6 short thick serrate bristles. Spines: all strong save on tibiae I and II; basal spine dorsally on femora I–IV very long. I: fe p1d3r1; pa 0; ti v2.2.0; me v2.2. II: fe p1d3r1; pa 0; ti v.1.1; me v2.2. III & IV: fe p2d3r2; pa r1; ti p2r2v2.2.2; me p3r3v2.1.1.3. Palp: p1d1; pa p1w; ti p2d2; ta p1d1r1v2 distal. Preening brush on retroventral metatarsus III and proventral IV. Abdomen: post-epigastric sclerites strongly Ushaped; tracheal scute small, conical. Epigyne: externally with two small U-shaped ridges; internally, with long simple lobes leading to enlarged head of spermatheca.

Distribution and Habitat. Known from tropical forest on Thursday Island, Torres Strait, and adjacent mainland at Somerset, and open eucalypt forest at the Steve Irwin Wildlife Reserve, both in Cape York, northeastern Queensland.

Remarks. The holotype is not in good condition because the moult was incomplete; the tips of chelicerae are still present. The female described here differs from the holotype in the conical form of the tracheal scute, which is a narrow transverse ridge.

Anchognatha was originally included by Thorell (1881) in the Clubionidae , where it was later transferred to the Sparassidae . While working through sparassid genera, David Hirst, then of the South Australian Museum, alerted me to the apparent corinnid affinities.

Figures

FIGURE 79. Nyssus spp., a, b, habitus: a, Nyssus luteofinis sp. nov. male, photo: T. Jinks; b, Nyssus albopunctatus (Hogg, 1896), female, photo: R. Raven; c, Nucastia supunnoides sp. nov, female, photo: G. Anderson; d, Nyssus avidus (Thorell, 1881), female. photo: R. Raven.

FIGURE 82. Nyssus avidus (Thorell, 1881), male QM S32159: a, b, palpal tibia, bulb and cymbium (mirrored), ventral (a) and retrolateral (b) views; female, QM S53444, c, d: epigyne, external (c), and internal (d).