Austropurcellia acuta, Popkin-Hall, Zachary R. & Boyer, Sarah L., 2014

Popkin-Hall, Zachary R. & Boyer, Sarah L., 2014, New species of mite harvestmen from southeast Queensland, Australia greatly extend the known distribution of the genus Austropurcellia (Arachnida, Opiliones, Cyphophthalmi), Zootaxa 3827 (4), pp. 517-541 : 525-529

Austropurcellia acuta sp. nov.

Figures 3–14

Diagnosis: Pettalid with relatively flat ozophores. Tergite VIII strongly bilobed, with bilobes clearly visible in both ventral and dorsal view. Lobes of tergite VIII lacking ornamentation dorsally and being only partially ornamented ventrally. Prominent scopula emerging from posterior margin of anal plate. Adenostyle thin and blade-like, with a wide base. Distinguished from A. capricornia by lobes of tergite VIII without ornamentation in dorsal view and with swollen appearance.

Description: Length of male holotype (2.1 mm) about twice as long as its widest point (1.2 mm) in posterior third of prosoma, and about 3 times as long as width across ozophores (0.8 mm) ( Figs. 3 , 4 A – B). Body with most of its surface showing a tuberculate-granular microstructure ( Fig. 4 ). Posterior part of dorsal scutum strongly bilobed, with scopula of anal plate easily visible in dorsal view ( Figs. 3 A, 4B). A pair of prominent depressions, anterior to ozophores in both male and female specimens, consisting of an indentation in the dorsal scutum with small tubercular structures clustered together ( Figs. 4 B, 6, 9A, 12A, 13). Transverse opisthosomal sulci distinct by lack of granulation ( Figs. 4 A – B, 9A – B, 12A – B). Ozophores quite flat in relation to dorsal scutum ( Figs. 3 A, C, 4B, 5B, 9A, 12A), positioned at a 45º angle relative to the walking plane as typical in pettalids.

Coxae of legs I and II mobile. Coxae of remaining legs fixed. Male coxae II – IV meeting in the midline ( Figs. 5 C, 10C). Male gonostome small, subtriangular, wider than long, bordered on posterior margin by first opisthosomal sternite; male gonostome shorter than length of seam of contact of left and right coxae IV ( Fig. 5 C, 10C). Female coxae II meeting in midline ( Fig. 12 D). Female gonostome roughly round in shape, with edges of coxae of leg IV and first opisthosomal sternite forming an elevated collar at posterior margin of opening ( Fig. 12 D).

Spiracle elongate and C-shaped, with slightly recurved edges as found in “open circle” type of Giribet and Boyer (2002). Narrow band of fine granules separating spiracle from main granules and tubercles ( Fig. 5 A, 10A). Ventral opisthosomal region without modifications or glandular pores ( Figs. 4 A, 9B). Anal region of “pettalid type’ ( Giribet & Boyer 2002) with tergite IX laterally covering sternite 9 and clearly meeting sternite 8 ( Fig. 4 C, 9D). Male tergite VIII strongly bilobed, with distinct lack of ornamentation in most distal area of each lobe, and with setae emerging medially from each lobe ( Figs. 4 C, 9D). Anal plate lacking in ornamentation in posterior half ( Figs.

4C, 9D). Very prominent scopula emerging posteriorly and extending to posterior margin of tergite VIII ( Figs. 4 C, 9D). Anal pore not visible.

Chelicerae ( Figs. 7 G – H, 11A) short and relatively robust. Proximal article of chelicerae with dorsal crest [“dorsal ridge” of Hansen & Sørensen (1904) and Forster (1948); “dorsal transverse crest” of Juberthie (1970)], without ventral process. Median article with an apodeme. Two types of dentition, as typical in pettalids ( Figs. 7 F, 11A). Measurements from male holotype of chelicera articles from proximal to distal (given in mm): 0.46, 0.91, 0.31.

Palp ( Figs. 7 E, 11B) with a prominent ventral process on trochanter. Measurements from paratype male of palp articles from proximal to distal (given in mm): 0.29, 0.37, 0.24, 0.28, 0.34.

Legs with all claws smooth, without ventral dentition or lateral pegs. Metatarsus I heavily ornamented in basal half but not in distal half, leading to the appearance of a “cuff”. Tarsus I smooth ( Figs. 7 A, 11C). Metatarsus II heavily ornamented in basal third but not in distal two thirds. Tarsus II smooth ( Figs. 7 B, 11D). Male leg III and both male and female leg IV with ornamented metatarsus and smooth tarsus ( Figs. 7 C – D, 11E – G). Ventral side of tarsus I with solea ( Figs. 7 A, 11C). Male tarsus IV fully bisegmented ( Figs. 7 D, 11F). Adenostyle with a thin claw on a wide base. Prominent pore visible on claw of adenostyle. Adenostyle projecting up and slightly distally ( Figs. 7 D, 11F). Measurements from male holotype of leg articles from proximal to distal (given in mm): leg I [femur damaged] 0.65, 0.27, 0.46, 0.16, 0.47; leg II [femur damaged] 0.54, 0.18, 0.33, 0.17, 0.40; leg III [femur damaged] 0.47, 0.21, 0.35, 0.19, 0.39; leg IV 0.18, 0.50, 0.26, 0.38, 0.15, 0.44.

Ovipositor ( Fig. 14 ) composed of two apical lobes and 29 circular articles. Apical lobes carrying several setae (increasing in length towards the tip); a long terminal seta rising from a small socket at end of each lobe. Sensitive processes each carrying many small microtrichia on distolateral area of each terminal lobe.

Spermatopositor small, typical of pettalids ( Fig. 8 ). Dorsal surface with a single, V-shaped series of very long microtrichia, 7 on the left and 8 on the right; apical lobe with 6 long microtrichia; ventral surface with 4 microtrichia. Gonopore complex with two movable fingers in the shape of pronounced hooks bent outward ( Fig. 8 B).

Type material: Australia, Queensland, Mapleton Forest Reserve, Bonyee Walk, off Mapleton Forest Drive (ArPTC#68); 26º33’28”S, 152º51’58”E; Coll. M.G. Rix, D. Harms, May 1, 2010; ♂ holotype, MCZ 30460 (ex MCZ 134701). Paratypes: Australia, Queensland, Mapleton Forest Reserve, Bonyee Walk, off Mapleton Forest Drive (ArPTC#68); 26º33’28”S, 152º51’58”E; Coll. M.G. Rix, D. Harms, May 1, 2010; 1 ♂ and 1 ♀; MCZ 30461 (ex MCZ 134701).

Other material: Australia, Queensland, Mapleton Forest Reserve, Bonyee Walk, off Mapleton Forest Drive (ArPTC#68); 26º33’28”S, 152º51’58”E; Coll. M.G. Rix, D. Harms, May 1, 2010; 1 ♂; MCZ 134701 ( DNA 106876). Australia, Queensland, Kroombit Tops, SSW Calliope, Beauty Spot 98; 24º22’S, 150º59’E, 860 m; Coll. G. Monteith, Sep. 29, 1985; 2 ♂ and 2 juveniles; QM S 1743.

Etymology: The specific epithet “ acuta ” is a Latin adjective meaning “pointed” or “sharpened” and refers to the very sharp tapering of the posterior end of the body relative to other Austropurcellia .

Figures

FIGURE 3. Austropurcellia acuta sp. nov., habitus of male holotype: A. Dorsal view; B. Ventral view; C. Lateral view. Scale bars 0.5 mm.

FIGURE 4. Austropurcellia acuta sp. nov., male paratype: A. Ventral view of body, scale bar 500 µm; B. Dorsal view of body, scale bar 500 µm; C. Ventral view of posterior, scale bar 200 µm; D. Dorsal view of posterior, scale bar 200 µm.

FIGURE 5. Austropurcellia acuta sp. nov., male paratype: A. Spiracle, scale bar 20 µm; B. Ozophore, scale bar 50 µm; C. Gonostome area, scale bar 200 µm.

FIGURE 6. Austropurcellia acuta sp. nov., male paratype: A. Cuticular structure in anterior region of dorsal scutum, scale bar 5 µm; B. Anterior dorsal cuticular structure (indicated by arrow) in context, scale bar 50 µm.

FIGURE 7. Austropurcellia acuta sp. nov., male paratype: A. Tarsus I, scale bar 200 µm; B. Tarsus II, scale bar 200 µm; C. Tarsus III, scale bar 200 µm; D. Tarsus IV, scale bar 200 µm; E. Palp, scale bar 200 µm; F. Detail of chelicera, scale bar 100 µm, G. Chelicera, distal segments, scale bar 200 µm, H. Chelicera, distal region of proximal segment, scale bar 200 µm.

FIGURE 8. Austropurcellia acuta sp. nov., male paratype, scale bars 40 µm: A. Spermatopositor in dorsal view; B. Spermatopositor with dorsal microtrichia cut away to reveal mobile fingers, distal microtrichia, and ventral microtrichia.

FIGURE 9. Austropurcellia cf. acuta sp. nov., male from Kroombit Tops: A. Dorsal view of body, scale bar 500 µm; B. Ventral view of body, scale bar 500 µm; C. Dorsal view of posterior, scale bar 100 µm; D. Ventral view of posterior, scale bar 100 µm.

FIGURE 10. Austropurcellia cf. acuta sp. nov., male from Kroombit Tops. A. Spiracle, scale bar 20 µm; B. Ozophore, scale bar 20 µm; C. Gonostome area, scale bar 200 µm.

FIGURE 11. Austropurcellia acuta sp. nov., male paratype (A – F), and Austropurcellia cf. acuta sp. nov., female from Kroombit Tops (G). A. Chelicera, scale bar 200 µm; B. Palp, scale bar 100 µm; C. Tarsus I, scale bar 100 µm; D. Tarsus II, scale bar 100 µm; E. Tarsus III, scale bar 100 µm; F. Male tarsus IV, scale bar 100 µm; G. Female tarsus IV, scale bar 200 µm.

FIGURE 12. Austropurcellia cf. acuta sp. nov., female from Kroombit Tops: A. Dorsal view of body, scale bar 500 µm; B. Ventral view of body, scale bar 500 µm; C. Ventral view of posterior, scale bar 100 µm; D. Gonostome area, scale bar 100 µm.

FIGURE 13. Austropurcellia cf. acuta sp. nov., female from Kroombit Tops: A. Cuticular structures in anterior region of dorsal scutum, scale bar 10 µm; B. Anterior dorsal structures (indicated by arrow) in context, scale bar 100 µm.

FIGURE 14. Austropurcellia cf. acuta sp. nov., female from Kroombit Tops: Distal part of ovipositor in dorsal view, scale bar 50 µm.