Difference between revisions of "Austrarchaea daviesae"

Latest revision as of 12:40, 30 August 2012

Taxonavigation

Ordo: Araneae
Familia: Archaeidae
Genus: Austrarchaea

Name

Austrarchaea daviesae Forster & Platnick, 1984 – Wikispecies link – Pensoft Profile

• Austrarchaea daviesae Forster & Platnick, 1984: 22, figs 66–68, 70–75.

Vernacular name

Misty Mountains Assassin Spider

Type material

Holotype male: Majors Mountain, [Tully Falls National Park], Atherton Tableland, Queensland, Australia, [17°38'25"S, 145°32'14"E], collected at night, 14–20.IV.1978, V. Davies, R. Raven (QMB S1091).
Paratypes: Allotype female, “Malaan State Forest” [= Malaan National Park], Atherton Tableland, Queensland, Australia, [17°35'S, 145°35'E], 20–24.IV.1978, V. Davies, R. Raven (QMB S1092).

Other material examined

AUSTRALIA: Queensland: Tully Falls National Park (Atherton Tableland): Massey Creek, 17°37'S, 145°34'E, flight intercept trap, 1000 m, 2–30.V.1996, P. Zborowski, 1♀ (ANIC). Malaan National Park (Atherton Tableland): “Malaan State Forest”, on Highway, 17°35'S, 145°35'E, pitfall trap, 850 m, 7.III.–15.V.1995, G. Monteith, J. Hasenpusch, 1 juvenile (QMB S38624); Mount Fisher, 7 km SW. of Millaa Millaa, pyrethrum knockdown, 1050–1100 m, 27–29.IV.1982, G. Monteith, D. Yeates, D. Cook, 1 juvenile (QMB S30838); next to Old Palmerston Highway, opposite Biggs Road, SSW. of Millaa Millaa, 17°35'11"S, 145°34'57"E, sifting elevated leaf litter at base of lawyer vine palms, tropical rainforest, 969 m, 18.III.2012, M. & A. Rix, 1♂, 1♀ (WAM T125183). Wooroonooran National Park: Mount Bartle Frere, inside Upper Boulder Caves, 17°23'S, 145°47'E, 1000 m, 12.V.1995, G. Monteith, D. Slaney, 1♀ (QMB S72989); same data except outside Lower Boulder Caves, 900 m, 13.V.1995, 1♀ (QMB S72987).

Other material (not examined)

AUSTRALIA: Queensland: Atherton Tableland: Bally Knob, summit, 17°39'S, 145°30'E, flight intercept trap, 1100 m, 6.XII.1998–6.II.1999, G. Monteith, D. Cook, 2♀ (QMB S50332). Wooroonooran National Park: Mount Bartle Frere, on track to summit, western side, from Junction Camp carpark off Gourka Road, 17°22'42"S, 145°47'09"E, day collecting, beating high and low vegetation, rainforest, 700–1300 m, 23–26.IV.2009, H. Wood, 3♂, 1♀ (CASENT 9034523); same data, 1♂ (CASENT 9034522); same data, 1 juvenile (CASENT 9034511); same data except day collecting, sifting leaf litter and small logs, brushing logs, mini-winkler, 1♀ (CASENT 9028381); Mount Bartle Frere, 18.4 km E. of Malanda, 17°22'46"S, 145°45'46"E, rainforest, 690–800 m, 17.III.2006, C. Griswold, D. Silva, M. Ramírez, 1 juvenile (CASENT 9023672).

Diagnosis

Austrarchaea daviesae can be distinguished from all other Archaeidae from north-eastern Queensland by the absence of a spur on the embolus (Fig. 7E) combined with a Type A pedipalp morphology (Fig. 6), i.e. with a large, arched, retrolaterally directed conductor (Figs 6, 7E), exposed embolus (Figs 6, 7E) and relatively short, spur-like tegular sclerite 3 (TS 3). This species can be further distinguished by the unique shape of TS 3, which has a broad tegular base and strongly hooked apex (Figs 7D-F; see also Forster and Platnick 1984^[1], figs 70–72, 74), and by the relatively short embolus, which projects beyond the distal rim of the conductor by ~1/3 the length of the exposed embolic portion (Figs 7D–E).

Description

Holotype male: Total length 2.74; leg I femur 2.73; F1/CL ratio 2.38. Cephalothorax tan-brown; legs pale tan-brown with darker annulations; abdomen mottled tan-brown and yellowish-beige (colour faded due to preservation) (Fig. 7B). Carapace tall (CH/CL ratio 2.08); 1.15 long, 2.38 high, 1.08 wide, ‘neck’ 0.62 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 0.67), carapace gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.27). Chelicerae with short brush of accessory setae on anterior face of paturon (Fig. 7C). Abdomen 1.54 long, 1.03 wide; with two pairs of dorsal hump-like tubercles (HT 1-4); dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to first pair of hump-like tubercles; HT 3-4 each covered by separate dorsal sclerites. Unexpanded pedipalp (of WAM T125183) (Figs 7D–F; see Forster and Platnick 1984^[1], figs 70–74 for SEM images of unexpanded holotype pedipalp) of Type A morphology (Fig. 6), with large, retrolaterally directed, arched conductor; embolus distally directed, slightly sinuous, without spur, projecting beyond distal rim of conductor by ~1/3 length of exposed embolic portion; tegular sclerite 3 (TS 3) short, spur-like, with broad tegular base and strongly hooked apex; TS 2-2a looped over retrolateral edge of conductor, TS 2 not strongly developed distally, TS 2a projecting beyond distal rim of conductor to just past tip of embolus; TS 1 very small, obscured by TS 2-3, not visible in ventral view.
Female (WAM T125183): Total length 3.44; leg I femur 2.97; F1/CL ratio 2.32. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled dark grey-brown and beige (Fig. 7A). Carapace tall (CH/CL ratio 2.11); 1.28 long, 2.71 high, 1.21 wide; ‘neck’ 0.71 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 gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.26). Chelicerae without accessory setae on anterior face of paturon. Abdomen 1.54 long, 1.37 wide; with four pairs of dorsal hump-like tubercles (HT 1-4). Internal genitalia (Fig. 7G) with cluster of 4-5 variably-shaped spermathecae on either side of gonopore, clusters widely separated along midline of genital plate; innermost (anterior) spermathecae longest, sausage-shaped, bent laterally; other spermathecae variably sausage-shaped or pyriform; posterior pair of spermathecae slightly separated posteriorly.
Variation: Males (Atherton Tableland; n = 2): total length 2.74–3.23; carapace length 1.15–1.18; carapace height 2.38–2.56; CH/CL ratio 2.08–2.17. Females (Atherton Tableland; n = 3): total length 3.44–3.49; carapace length 1.26–1.32; carapace height 2.7–-2.77; CH/CL ratio 2.10–2.15. Females (Mount Bartle Frere; n = 2): total length 3.64–3.79; carapace length 1.40 (invariable); carapace height 2.97 (invariable); CH/CL ratio 2.13 (invariable). Although female specimens from Mount Bartle Frere appear to be slightly larger than those from further west (Fig. 5), carapace proportions and genitalia seem otherwise very similar to specimens from the Atherton Tableland (see Remarks, below).

Distribution and habitat

Austrarchaea daviesae is known from the ‘Misty Mountains’ region of the southern Atherton Tableland, in the vicinity of Ravenshoe and Millaa Millaa, with additional specimens also known from Mount Bartle Frere in the adjacent Wooroonooran National Park (see Remarks, below) (Figs 16, 25). Specimens have been collected in pitfall and flight intercept traps, by beating vegetation, or by beating and sifting elevated leaf litter at the bases of lawyer vine palms (Calamus spp.) in dense tropical rainforest (Fig. 1F).

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.

Remarks

The identification and distribution of Austrarchaea daviesae has, until recently, been difficult to ascertain, as the holotype male (QMB S1091; Fig. 7B) is without pedipalps (these presumably having been mounted on SEM stubs as per Forster and Platnick 1984^[1], figs 70–74). Similarly, no adult male specimens had been collected from the Atherton Tableland since the original holotype collection in 1978. Fortunately, an adult male and female were collected in early 2012, from the paratype locality (Malaan National Park), near the type locality of Majors Mountain. These specimens (WAM T125183), described above, closely conform to original descriptions, and the male pedipalp appears indistinguishable from that illustrated in Forster and Platnick (1984^[1], figs 70–74). Interestingly, the distribution of Austrarchaea daviesae appears to extend beyond the Atherton Tableland, with eastern populations apparently sympatric or at least partly sympatric with Austrarchaea woodae sp. n. on Mount Bartle Frere, in the Wooroonooran National Park. Adult Mount Bartle Frere specimens collected by the California Academy of Sciences in 2009 are conspecific with specimens from Malaan National Park, as confirmed by pedipalp images supplied by H. Wood (pers. comm.). Another juvenile specimen from Mount Bartle Frere (CASENT 9023672), collected in 2006, is also conspecific with these adult Mount Bartle Frere specimens, as determined by almost identical COI sequences (H. Wood, pers. comm.). Interestingly, female specimens collected by the QM from Boulder Caves, near the type locality of Austrarchaea woodae sp. n., also appear to be Austrarchaea daviesae (rather than Austrarchaea woodae sp. n.), due to the presence of fully developed (rather than recumbent) abdominal tubercles, and a similar carapace morphology and similar genitalia to specimens from the Atherton Tableland. Austrarchaea woodae sp. n. thus appears to be much rarer than Austrarchaea daviesae at altitudes ≤ ~1000 m, and may actually be restricted to higher altitude montane rainforest on the summit of Mount Bartle Frere.

Taxon Treatment

• Rix, M; Harvey, M; 2012: Australian Assassins, Part III: A review of the Assassin Spiders (Araneae, Archaeidae) of tropical north-eastern Queensland ZooKeys, 218: 1-50. doi

Images

'Figure 1. Habitus and habitat images of species Archaeidae from north-eastern Queensland. A–D, Habitus images of live paratype specimens of Austrarchaea griswoldi sp. n. from Eungella National Park: A newly-moulted female with recently cast cuticle; B–C, female, lateral view; D, female carrying egg-sac. E–F, Habitat images: E, tropical rainforest at Broken River, Eungella National Park – type locality of Austrarchaea griswoldi sp. n.; F, dense tropical rainforest at Malaan National Park, Atherton Tableland – locality of Austrarchaea daviesae Forster & Platnick.  Figure 5. Graphs depicting the relationship between carapace length (CL) and carapace height (CH) for species of Austrarchaea from north-eastern Queensland. Smaller grey dots denote species of Austrarchaea from mid-eastern Australia (see Rix and Harvey 2011[2]); smaller grey squares denote species of Zephyrarchaea from southern Australia (see Rix and Harvey 2012a[3]). Note the relatively large body sizes of Austrarchaea hoskini sp. n. and Austrarchaea woodae sp. n., and the body size variation between populations of Austrarchaea daviesae from the Atherton Tableland (AT) and Mount Bartle Frere (Mt BF), respectively.  Figure 6. Morphological differences between the five pedipalp types (Types A-E) identified for species of Austrarchaea from north-eastern Queensland, with left bulbs illustrated in ventral view at scale-identical sizes. Type A pedipalps are shared among at least five species from the Wet Tropics bioregion; Types B-E are autapomorphic for single species. Note especially the variation in the size and shape of the bulb, and the shape and orientation of the conductor. C = conductor; E = embolus; ESp = embolic spur; (TS)1-3 = tegular sclerites 1-3. Scale bar = 0.2 mm.  Figure 7. Austrarchaea daviesae Forster & Platnick, 1984. A–B, Cephalothorax and abdomen, lateral view: A, female (WAM T125183) from Malaan National Park, Atherton Tableland, NE. Queensland; B, holotype male (QMB S1091) from Majors Mountain, Atherton Tableland, NE. Queensland. C, Holotype male chelicerae, lateral view, showing accessory setae. D–F, Male (WAM T125183; from Malaan National Park, Atherton Tableland, NE. Queensland) pedipalp: D–E, bulb, ventral view; F, detail of distal tegular sclerites, retrolateral view. G, Female (WAM T125183) internal genitalia, postero-ventral view (genital plate removed). C = conductor; E = embolus; T = tegulum; (TS)2-3 = tegular sclerites 2-3. Scale bars: A-B = 1.0 mm; E = 0.2 mm.  Figure 16. Distribution of Austrarchaea daviesae Forster & Platnick, 1984: A, topographic map showing the known distribution of Archaeidae in the north-eastern Queensland Wet Tropics bioregion, with collection localities for Austrarchaea daviesae highlighted in yellow; B–C, topographic and satellite maps showing detail of inset (A). Labelled boundaries in (B) denote upland subregional zones of faunal endemism identified by Winter et al. (1984), Williams et al. (1996) and other authors for the central Wet Tropics (modified from Edward 2011). Small squares in (B–C) denote unidentified juvenile specimens; small circles denote unidentified female specimens; large circles denote described species of Austrarchaea. AU = Atherton Uplands; BK = Bellenden Ker/Bartle Frere; HI = Hinchinbrook Island; KU = Kirrama Uplands; LE = Lee Uplands; LU = Lamb Uplands; MT = Malbon-Thompson Uplands.  ' Figure 25. Summary distribution of the Austrarchaea daviesae species-group in tropical north-eastern Queensland, showing collections records for described species (labelled, with black circles) and unidentified juveniles or females (yellow circles) (see Table 1). Note the high proportion of unidentified specimens, especially within the Wet Tropics bioregion between Cooktown and Ingham.

Other References

1. ↑ ^{1.0 1.1 1.2 1.3} 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. ↑ 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: 10.3897/zookeys.123.1448
3. ↑ Rix M, Harvey M (2012a) Australian Assassins, Part II: a review of the new assassin spider genus Zephyrarchaea (Araneae, Archaeidae) from southern Australia. ZooKeys 191: 1-62. doi: 10.3897/zookeys.191.3070