Difference between revisions of "Austrarchaea nodosa"

Latest revision as of 15:58, 15 August 2011

Taxonavigation

Ordo: Araneae
Familia: Archaeidae
Genus: Austrarchaea

Name

Austrarchaea nodosa (Forster, 1956) – Wikispecies link – Pensoft Profile

• Archaea nodosa Forster, 1956: 151, figs 1–7.
• Austrarchaea nodosa (Forster): Forster & Platnick, 1984: 21, figs 4–6, 9–10, 19, 27, 34–35, 57, 60–65.

Type material

Holotype juvenile: Lamington National Park, Tullawallal [Antarctic Beech forest], south of Binna Burra, Queensland, Australia, [28°12'20"S, 153°11'20"E], from moss, 31.X.1955, T. Woodward (QMB W1955).

Other material examined

AUSTRALIA: Queensland: Lamington National Park: Binna Burra, track to Tullawallal Antarctic Beech forest, 28°12'20"S, 153°11'20"E, sifting and teasing low vegetation, 7.IV.2006, M. & A. Rix, 1♂, 2 juveniles (WAM T89592DNA: LAM-51-J); Binna Burra, 11.II.1971, Y. Lubin, R. Raven, V. Davies, 1♀ (QMB S73925); Binna Burra, Ships Stern Circuit track, 28°11'51"S, 153°11'28"E, sifting elevated leaf litter, subtropical rainforest, 764 m, 25.IV.2010, M. & A. Rix, D. & S. Harms, J. Wojcieszek, 1 juvenile (WAM T112571DNA: Ar56-58-J); IBISCA Plot IQ-1100-A, 28°15'29"S, 153°09'32"E, bark spray, 1141 m, 11.III.2007, G. Thompson, A. Marcora, 1♂, 1♀, 1 juvenile (QMB S75416). New South Wales: Border Ranges National Park: Upper Brindle Creek, Wiangarie, 28°23'S, 153°06'E, pyrethrum, Nothofagus rainforest, 840 m, 15.XII.2008, G. Monteith, 1♀ (QMB S87983). Mount Warning National Park: 1975–1976, G. & S. Monteith, 1 juvenile (QMB S20426); Mount Warning, track to summit, 28°24'08"S, 153°16'27"E, sifting elevated leaf litter under Xanthorrhoea, wet eucalypt forest bordering subtropical rainforest, 728 m, 26.IV.2010, M. Rix, 1 juvenile (WAM T112572DNA: Ar57-46-J); off Mount Warning Road, 28°23'51"S, 153°17'20"E, sifting elevated leaf litter, subtropical rainforest, 348 m, 26.IV.2010, D. Harms, 1 juvenile (WAM T112573DNA: Ar58-53-J).

Additional material examined (of tentative identification)

AUSTRALIA: Queensland: Lamington National Park: Mount Hobwee, in moss, 3.IV.1976, R. Raven, 1 juvenile (QMB S30827); Nagarigoon, 8.IV.1976, 1 juvenile (QMB S30817). Mount Chinghee National Park: QM Berlesate, stick brushing, 17.XII.1982, G. Monteith, D. Yeates, G. Thompson, 1 juvenile (QMB S30804). New South Wales: Border Ranges National Park: Border Fence, Levers Plateau, via Rathdowney, pitfall trap, 670 m, 22.V.–IX.1976, G. & S. Monteith, 1 juvenile (QMB S30823).

Additional material (not examined)

AUSTRALIA: Queensland: Lamington National Park: Tullawallal Antarctic Beech forest, south of Binna Burra, 28°12'39"S, 153°11'32"E, Nothofagus rainforest, 900 m, 21.III.2006, C. Griswold, D. Silva, R. Raven, B. Baehr, M. Ramírez, 1♂ (CASENT 9018966); Binna Burra, 27.III.1976, R. Raven, V. Davies, 1♀, 1 juvenile (QMB S30820); Binna Burra, 28°11'38"S, 153°11'13"E, rainforest, 790 m, 21-23.III.2006, C. Griswold, D. Silva, R. Raven, B. Baehr, M. Ramírez, 1 juvenile (CASENT 9018963); Binna Burra, 28°11'38"S, 153°11'13"E, Berlese of leaf litter, rainforest, 790 m, 23.III.2006, C. Griswold, D. Silva, R. Raven, B. Baehr, M. Ramírez, 1 juvenile (CASENT 9018964); Binna Burra, along Border Track, 28°11'56"S, 153°11'15"E, beating vegetation, 900 m, 29–30.IV.2009, H. Wood, 1♂ (CASENT 9028426); same data, 1♂ (CASENT 9028388); O'Reillys, 25-26.IX.1986, J. Gallon, R. Raven, 1♀ (QMB S30814).

Diagnosis

Austrarchaea nodosa can be distinguished from all other Archaeidae from mid-eastern Australia by the broad, flanged proximal portion of the embolic sclerite (Figs 10D-E; see also Forster and Platnick 1984^[1], figs 61, 63) and the unique shape of the conductor (Figs 10D-E), which is thin, gently-tapered and slightly bent along its distal half. The presence of a shallow concave depression near the posterior margin of the ‘head’ (Fig. 7I) can also be used to distinguish females from most other species, including the sympatric Austrarchaea dianneae sp. n.
This species can also be distinguished from other genotyped taxa from mid-eastern Australia (see Fig. 3B) by the following seven unique nucleotide substitutions for COI (n = 4): A(42), C(393), C(639), C(939), A(960), A(1038), A(1053).

Description

Male (QMB S30817): Total length 3.18; leg I femur 3.01; F1/CL ratio 2.70. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, with darker reddish-brown dorsal scute and sclerites (Fig. 10B). Carapace very tall (CH/CL ratio 2.30); 1.12 long, 2.56 high, 1.08 wide; ‘neck’ 0.56 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near middle of ‘head’ (ratio of HPC to post-ocular length 0.57), carapace with shallow concave depression posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.24) (Fig. 8I). Chelicerae with short brush of accessory setae on anterior face of paturon (Fig. 10C). Abdomen 1.64 long, 1.13 wide; with three pairs of dorsal hump-like tubercles (HT 1–6); dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to first pair of hump-like tubercles; HT 3–6 each covered by separate dorsal sclerites. Unexpanded pedipalp (WAM T89592) (Figs 10D-F) with thin, pointed conductor, gently-tapered and slightly bent along distal half; embolic sclerite with broad, flanged proximal portion overlying proximal conductor; tegular sclerite 1 (TS 1) long, filiform, with sinuous distal tip, visible in retrolateral view; TS 2 spiniform, shorter than TS 1; TS 2a sinuous, largely obscured by TS 2; TS 3 indistinct, embedded within distal haematodocha, barely visible beyond retro-distal rim of tegulum.
Female (QMB S30817): Total length 3.54; leg I femur 3.01; F1/CL ratio 2.40. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen bi-coloured grey-brown and beige, palest posteriorly (Fig. 10A). Carapace tall (CH/CL ratio 2.12); 1.26 long, 2.67 high, 1.15 wide; ‘neck’ 0.64 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near posterior third of ‘head’ (ratio of HPC to post-ocular length 0.63), carapace with shallow concave depression posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.23) (Fig. 7I). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.15 long, 1.64 wide; with three pairs of dorsal hump-like tubercles (HT 1–6). Internal genitalia with cluster of ≤ 12 variably shaped spermathecae on either side of gonopore, clusters meeting near midline of genital plate (Figs 5D, 10G); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; outermost (posterior) spermathecae bulbous; other spermathecae variably pyriform, straight, directed antero-laterally.
Variation: Males (n=2): total length 2.97–3.18; carapace length 1.12–1.13; carapace height 2.56–2.67; CH/CL ratio 2.30–2.36. Females (n=3): total length 3.54–4.00; carapace length 1.21–1.33; carapace height 2.49–2.87; CH/CL ratio 2.06–2.15.

Distribution and habitat

Austrarchaea nodosa is known from rainforest habitats along the McPherson Range and ‘scenic rim’ of extreme south-eastern Queensland and north-eastern New South Wales, in the Lamington, Border Ranges and Mount Warning National Parks (Fig. 28). At Binna Burra (Lamington National Park) it has been found in sympatry with Austrarchaea dianneae sp. n., in the only known example of two-species sympatry among Australian archaeids (see Nomenclatural Remarks, below).

Conservation status

This species has a relatively widespread distribution in several National Parks protected under World Heritage legislation, and is not considered to be of conservation concern.

Nomenclatural remarks

The holotype specimen of Austrarchaea nodosa, described by Forster (1956)^[2], is a juvenile (probably penultimate) female from the Tullawallal Nothofagus forest near Binna Burra, Lamington National Park. Although long assumed to have only a single species, the greater Binna Burra region is now the only locality in Australia known to have two species of Archaeidae living in close sympatry: numerous specimens of Austrarchaea dianneae sp. n. were discovered near Binna Burra in April 2010, along the ‘Ships Stern Circuit Track’, along with one juvenile specimen of Austrarchaea nodosa. Both Austrarchaea dianneae sp. n. and Austrarchaea nodosa are closely related (Fig. 3B) rainforest-dwelling taxa, rendering the identification of Forster’s holotype specimen – and therefore the identification of the generic type species – questionable. To address this issue, and to determine which species was actually described by Forster (1956)^[2], two lines of evidence are discussed below.
‘Tullawallal’ – the type locality cited by Forster (1956)^[2] – is a well-known, high-altitude Nothofagus moorei cool-temperate rainforest, situated off Binna Burra’s ‘Border Track’ at around 900 m elevation. The dominant rainforest surrounding Tullawallal is a closed, complex notophyllous vine forest (with isolated warm-temperate and cool-temperate elements), typical of higher elevations throughout the Lamington National Park and McPherson Range (Fig. 28C). In all of the higher-altitude and/or closed rainforests of the Lamington Plateau and Border Ranges National Park, only identifiable specimens of Austrarchaea nodosa (as recognised above) have so far been collected. Furthermore, the two male specimens collected at or near Tullawallal (WAM T89592, CASENT 9018966) are also both Austrarchaea nodosa as here recognised. In contrast, the three localities where Austrarchaea dianneae sp. n. has been found (i.e. along the ‘Ships Stern Circuit Track’ near Binna Burra, Wojigumal Creek, and in the Tamborine National Park) are significantly lower in altitude than Tullawallal and the surrounding ‘Border Track’ region of Binna Burra (764 m, 570 m and 313 m, respectively), with more open ‘mixed’ rainforests and emergent eucalypts at the Binna Burra and Mount Tamborine localities (Fig. 29C).
Secondly, female specimens of both species possess a distinctive ‘head’ morphology; females of Austrarchaea nodosa (as here recognised) are characterised by a shallow concave depression posterior to the highest point of the pars cephalica (HPC) (Fig. 7I), whereas females of Austrarchaea dianneae sp. n. have no such depression and a significantly more pronounced posterior margin of the ‘head’ (Fig. 7H). The holotype juvenile specimen of Austrarchaea nodosa has a clear concave depression posterior to the HPC, and ‘head’ proportions otherwise very similar to the female illustrated in Figure 7I. In contrast, the only known penultimate female specimen of Austrarchaea dianneae sp. n., collected from near Binna Burra (WAM T112556), does not have a concave depression posterior to the HPC, and ‘head’ proportions otherwise similar to the allotype female Austrarchaea dianneae sp. n. illustrated in Figure 7H.
Clearly, given the identification of specimens collected from the type locality and similar nearby habitats, and the morphology of the holotype juvenile specimen, we are as confident as possible in newly-diagnosing Austrarchaea nodosa as the species described above, given an otherwise highly precarious nomenclatural situation.

Taxon Treatment

• Rix, M; Harvey, M; 2011: Australian Assassins, Part I: A review of the Assassin Spiders (Araneae, Archaeidae) of mid-eastern Australia ZooKeys, 123: 1-100. doi

Other References

1. ↑ Forster R, Platnick N (1984) A review of the archaeid spiders and their relatives, with notes on the limits of the superfamily Palpimanoidea (Arachnida, Araneae). Bulletin of the American Museum of Natural History 178: 1-106.
2. ↑ ^{2.0 2.1 2.2} Forster R (1956) A new spider of the genus Archaea from Australia. Memoirs of the Queensland Museum 13: 151-154.

Images

Figure 1. Habitus images of live Archaeidae from mid-eastern Australia: A–B, female Austrarchaea nodosa (Forster, 1956) from Binna Burra, Lamington National Park, Queensland; C–D, female A. mascordi sp. n. from Coolah Tops National Park, New South Wales; E–F, juvenile A. raveni sp. n. from Mount Glorious, Queensland. Images A–D by M. Rix; images E–F by Greg Anderson, used with permission.  Figure 3. Molecular phylogenetic data analysed as part of this study. A, Schematic map of the mitochondrial cytochrome c oxidase subunit I–II (COI–COII) gene complex in Archaeidae and other basal Araneomorphae, showing (i) the position of primers used to amplify and sequence 1.6 kilobases of mtDNA, and (ii) the inferred stop and initiation codons for COI and COII, respectively. Note the centralised, overlapping position of the two internal sequencing primer sites (SeqF2a/SeqR1), and the TTG initiation codon for COII, present in all but one of the spider species sequenced for this study. B, Majority-rule consensus tree with re-estimated branch lengths, resulting from a combined, gene-partitioned Bayesian analysis of the COI–COII mtDNA data. Thickened branches represent clades with >95% posterior probability support, and individual support values are shown above other nodes.  Figure 5. Abdominal morphology of Austrarchaea species. A–C, A. judyae sp. n.: A, male abdomen, antero-lateral view, showing dorsal scute (S) and additional dorsal sclerites (ds); B, detail of female abdomen, lateral view, showing subcuticular guanine crystals (GC) and concentric arrangements of setae around sclerotic spots (ss); C, female epigastric region, ventral view, showing setose book lung covers (BL) and genital plate (GP). D, Cleared epigastric region of female A. nodosa (Forster), postero-ventral view, showing position of clustered spermathecae under posterior rim of genital plate. E–G, Female abdomens, postero-lateral view, showing arrangement of dorsal hump-like tubercles (HT) in different taxa: E, A. sp. nr. daviesae (QMB S72989, from Mount Bartle Frere, NE. Queensland); F, A. monteithi sp. n.; G, A. aleenae sp. n. Note the presence of only a single posterior hump-like tubercle (HT 5) in A. monteithi.  Figure 7. Lateral ‘head’ profiles of females of species of Austrarchaea from mid-eastern Australia, showing variation in carapace shape as quantified by the post-ocular ratio (P.O. Ratio) and ratio of highest point of carapace relative to post-ocular length (HPC Ratio): A, allotype A. alani sp. n.; B, allotype A. aleenae sp. n.; C, allotype A. judyae sp. n.; D, allotype A. raveni sp. n.; E, allotype A. harmsi sp. n.; F, allotype A. monteithi sp. n.; G, allotype A. cunninghami sp. n.; H, allotype A. dianneae sp. n.; I, A. nodosa (Forster, 1956); J, allotype A. platnickorum sp. n.; K, allotype A. binfordae sp. n.; L, A. milledgei sp. n. (WAM T112568); M, allotype A. mascordi sp. n.; N, allotype A. smithae sp. n.; O, allotype A. mcguiganae sp. n. Asterisks (*) denote concave depressions.  Figure 8. Lateral ‘head’ profiles of males of species of Austrarchaea from south-eastern Queensland and extreme north-eastern New South Wales (including the Border Ranges), showing variation in carapace shape as quantified by the post-ocular ratio (P.O. Ratio) and ratio of highest point of carapace relative to post-ocular length (HPC Ratio): A, holotype A. alani sp. n.; B, holotype A. aleenae sp. n.; C, holotype A. judyae sp. n.; D, holotype A. raveni sp. n.; E, holotype A. harmsi sp. n.; F, holotype A. clyneae sp. n.; G, holotype A. cunninghami sp. n.; H, holotype A. dianneae sp. n.; I, A. nodosa (Forster, 1956) (QMB S75416). Asterisks (*) denote concave depressions.  Figure 10. Austrarchaea nodosa (Forster, 1956). A–B, Cephalothorax and abdomen, lateral view: A, female (QMB S75416) from Lamington National Park, Queensland; B, male (QMB S75416) from Lamington National Park, Queensland. C, Male chelicerae, lateral view, showing accessory setae. D–F, Male (WAM T89592) pedipalp: D–E, bulb, retrolateral view; F, detail of distal tegular sclerites, prodistal view. G, Female (QMB S75416) internal genitalia, dorsal view. C = conductor; E = embolus; Es = embolic sclerite; T = tegulum; (TS)1–3 = tegular sclerites 1–3. Scale bars: A–B = 1.0 mm; E = 0.2 mm.  Figure 28. Austrarchaea nodosa (Forster, 1956), distribution and habitat: A, topographic map showing the known distribution of Archaeidae in south-eastern Queensland and eastern New South Wales, with collection localities for A. nodosa highlighted in yellow (red highlighted localities denote juvenile specimens of tentative identification); B, satellite image showing detail of inset (A); C, subtropical rainforest near the type locality – Binna Burra, Lamington National Park, Queensland (April 2010). Image (C) by M. Rix.