Zephyrarchaea melindae Rix & Harvey

Rix, Michael G. & Harvey, Mark S., 2012, Australian Assassins, Part II: A review of the new assassin spider genus Zephyrarchaea (Araneae, Archaeidae) from southern Australia, ZooKeys 191, pp. 1-62 : 15

Zephyrarchaea melindae Rix & Harvey sp. n. Figs 8E9H1424

Toolbrunup Assassin Spider

Type material.

Holotype male: Stirling Range National Park, Mount Hassell, Western Australia, Australia, 34°22'41"S, 118°04'15"E, sifting elevated leaf litter under Lepidosperma sedges near summit, 726 m, 22.IV.2009, M. Rix (WAM T118986).

Paratypes: Allotype female and 1 juvenile, Toolbrunup Peak, 34°23'02"S, 118°02'55"E, sifting elevated leaf litter under low herbaceous shrubs near summit, 964 m, 10.IV.2009, M. Rix, H. Wood (WAM T97468DNA: TP-152-F/TP-153-J).

Other material examined.

AUSTRALIA: Western Australia:Stirling Range National Park: same data as holotype, 2 juveniles (WAM T97467DNA: HA-150-J/HA-151-J).

Etymology.

The specific epithet is a patronym in honour of Dr Melinda Moir, in recognition of her contributions to biodiversity research, especially in the Stirling Range National Park of southern Western Australia.

Diagnosis.

Zephyrarchaea melindae can be distinguished from Zephyrarchaea janineae and Zephyrarchaea mainae by the absence of dorsal hump-like tubercles on the abdomen (Figs 14 A–B); from Zephyrarchaea marae sp. n., Zephyrarchaea marki , Zephyrarchaea porchi sp. n. and Zephyrarchaea vichickmani sp. n. by the shape of tegular sclerites 2-3, which do not project beyond the retro-distal rim of the tegulum (Figs 14 D–E); and from Zephyrarchaea barrettae sp. n. by the shape of the anterior margin of the diastema adjacent to the ‘neck’, which is straight (in females) or only slightly concave in lateral view (in males) (Figs 14 A–B cf. Figs 15 A–B). Females further distinguished from other known congeners by the combination of a spherical abdomen (Fig. 14A), shallow post-ocular depression in lateral view (Fig. 9H), taller carapace (CH/CL ratio> 1.70) (Figs 7, 14A) and straight, almost vertical anterior margin of the diastema adjacent to the ‘neck’ (Fig. 14A).

This species can also be distinguished from other genotyped taxa (see Fig. 3) by the following three unique nucleotide substitutions for COI and COII (n = 4): G(165), G(924), T(1533).

Description.

Holotype male: Total length 3.15; leg I femur 2.37; F1/CL ratio 2.01. Cephalothorax dark reddish-brown; legs tan brown with darker annulations; abdomen mottled grey-brown and beige, with reddish-brown dorsal scute and sclerites (Fig. 14B). Carapace relatively short (CH/CL ratio 1.77); 1.18 long, 2.09 high, 1.18 wide; ‘neck’ 0.68 wide; highest point of pars cephalica (HPC) approaching posterior third of ‘head’ (ratio of HPC to post-ocular length 0.62), carapace with shallow concave depression anterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.20) (Fig. 8E). Chelicerae with proximal brush and additional comb of accessory setae on anterior face of paturon (Fig. 14C). Abdomen 1.64 long, 1.23 wide; almost spherical in lateral profile, without dorsal hump-like tubercles; dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to cover anterior two-thirds of dorsal abdomen. Unexpanded pedipalp (Figs 14 D–F) pyriform, with broad, distally curved embolus supported by conductor sclerites 1-2; tegular sclerite 1 (TS 1) strongly curved, claw-like in prolateral view, with twisted, flattened and broadly rounded apex; TS 2-3 not projecting beyond retro-distal rim of tegulum.

Allotype female: Total length 3.54; leg I femur 2.50; F1/CL ratio 1.93. Cephalothorax dark reddish-brown; legs tan brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 14A). Carapace relatively short (CH/CL ratio 1.86); 1.29 long, 2.41 high, 1.28 wide; ‘neck’ 0.78 wide; highest point of pars cephalica (HPC) approaching middle of ‘head’ (ratio of HPC to post-ocular length 0.57), carapace with shallow concave depression anterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.19) (Fig. 9H). Chelicerae without accessory setae on anterior face of paturon. Abdomen 1.95 long, 1.51 wide; spherical in lateral profile, without dorsal hump-like tubercles. Internal genitalia (Fig. 14G) with cluster of ≤ 15 sausage-shaped spermathecae either side of gonopore, clusters widely separated along midline of genital plate.

Distribution and habitat.

Zephyrarchaea melindae is known only from the summits of Toolbrunup Peak and nearby Mount Hassell, in the western Stirling Range National Park of southern Western Australia (west of Chester Pass) (Fig. 24). Specimens have been collected by beating and sifting sedges ( Lepidosperma sp.) and low shrubs in montane heathland habitats.

Conservation status.

This species is a short-range endemic taxon ( Harvey 2002b), with a maximum total range of less than 10 km2, and all known populations in the western Stirling Range National Park potentially threatened by fire, dieback disease (affecting montane vegetation) and climate change.