Zephyrarchaea austini 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 : 22-23

Zephyrarchaea austini Rix & Harvey sp. n. Figs 9D19C-D30

Kangaroo Island Assassin Spider

Type material.

Holotype female: Kangaroo Island, Western River Wilderness Protection Area, Waterfall Creek walking trail, near waterfall, South Australia, Australia, 35°41'44"S, 136°54'37"E, sifting elevated leaf litter, open eucalypt woodland with complex understorey of Xanthorrhoea and low shrubs, 9-10.V.2010, M. Rix, D. Harms (SAM NN28000DNA:Ar77-50-F).

Other material examined.

AUSTRALIA: South Australia:Western River Wilderness Protection Area: same data as holotype, 3 juveniles (WAM T114027DNA: Ar77-142-J/Ar77-143-J).

Etymology.

The specific epithet is a patronym in honour of Professor Andy Austin, in recognition of his contributions to biodiversity research.

Diagnosis.

Females of Zephyrarchaea austini can be distinguished from Zephyrarchaea janineae and Zephyrarchaea mainae by the absence of dorsal hump-like tubercles on the abdomen (Fig. 19C); from Zephyrarchaea barrettae , Zephyrarchaea melindae and Zephyrarchaea robinsi by the strongly concave post-ocular depression in lateral view (Fig. 9D); and from Zephyrarchaea grayi , Zephyrarchaea marae and Zephyrarchaea vichickmani by the smaller body size (carapace length <1.10) and shorter carapace (CH/CL ratio <1.70) (Figs 7, 19C).

This species can also be distinguished from other genotyped taxa (see Fig. 3) by the following 45 unique nucleotide substitutions for COI and COII (n = 3): T(42), A(45), C(130), T(132), G(222), A(243), G(291), A(354), G(360), T(372), A(453), A(504), G(567), G(648), A(690), A(702), C(717), C(721), G(756), C(852), A(858), A(891), G(901), A(910), G(962), C(971), G(1050), G(1165), G(1197), A(1198), T(1233), G(1234), C(1235), T(1236), G(1317), A(1374), A(1403), T(1404), G(1416), G(1418), A(1419), A(1449), T(1530), G(1574), G(1585).

Description.

Holotype female: Total length 2.77; leg I femur 1.80; F1/CL ratio 1.80. Cephalothorax pale reddish-brown; legs tan brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 19C). Carapace short (CH/CL ratio 1.58); 1.00 long, 1.58 high, 0.92 wide; ‘neck’ 0.55 wide; highest point of pars cephalica (HPC) near posterior third of ‘head’ (ratio of HPC to post-ocular length 0.67), carapace with pronounced concave depression anterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.23) (Fig. 9D). Chelicerae without accessory setae on anterior face of paturon. Abdomen 1.49 long, 1.13 wide; almost spherical in lateral profile, without dorsal hump-like tubercles. Internal genitalia (Fig. 19D) with cluster of ≤ 15 sausage-shaped spermathecae fanning out either side of gonopore, clusters widely separated along midline of genital plate.

Male: Unknown.

Distribution and habitat.

Zephyrarchaea austini is known only from eucalypt woodland and associated heathland habitats near 'Billy Goat Falls’, in the Western River Wilderness Protection Area of Kangaroo Island, South Australia (Fig. 30).

Conservation status.

This species appears to be a rare short-range endemic taxon ( Harvey 2002b), with the single known population on Kangaroo Island potentially threatened by fire, dieback disease (affecting heathland vegetation) and climate change.