Unixenus barrabaensis Short & Huynh

Short, Megan & Huynh, Cuong, 2013, Four new species of Unixenus Jones, 1944 (Diplopoda, Penicillata, Polyxenida) from Australia, ZooKeys 278, pp. 75-90 : 81-83

Unixenus barrabaensis Short & Huynh sp. n. Fig. 3 A–I

Holotype.

Female, Crown Reserve, Woods Reef, between road and Nangahrah Ck. NSW, 30°23'39"S, 150°44'08"E, pitfall traps 18 November– 9 December 2001, col lected by H. Doherty and M. Elliot, AM KS.119545. Specimen mounted on slide, deposited in AM.

Paratypes.

Male subadult stadium VII, same collection as holotype, AM KS.119546. Male subadult stadium VII Crown Reserve, 8.9 km along Bukkulla-Ashford Rd., NSW, 29°25'59"S, 151°04'18"E, pitfall traps 22 November– 13 December 2001, collected by H. Doherty and M. Elliot, AM KS.119547. Female, stadium VII, Oaky Creek Nature Reserve, at base of E side of Melville Range, 31°06'31"S, 150°37'20"E, wet pitfall traps 17 November– 8 December 2001, collected by L. Wilkie and H. Smith, AM KS.119548. Specimens mounted on slides, deposited in AM.

Etymology.

For Barraba, town closest to type locality; adjective.

Diagnosis.

Chaetotaxy similar to Unixenus mjoebergi with leg setae being spiny, 2 setae on femur and 1 on tibia; differs from Unixenus mjoebergi in having four basiconic sensilla on antennal article VI.

Description.

As for Unixenus carnarvonensis sp. n., differing in the following details:

Measurements: female adult, 1.94 mm, caudal bundle 0.3 mm; male subadult, Stadium VII, 1.6-2.1 mm. (n=3), caudal bundle 0.3 mm.

No freshly collected specimens available. Specimens had been preserved in 70% ethanol. Body yellow brown in colour with brown tergal trichomes.

Two rows of trichomes either side of posterior vertex of head with slightly larger medial gap than for Unixenus carnarvonensis sp. n. Number of trichomes each side of posterior vertex varies 8-14 (anterior rows), 4-6 (posterior rows) (Fig. 3A). Antennal article VI with 4 thick basiconic sensilla, coeloconic sensillum posterior to basiconic sensilla, One setiform sensillum anterior to the basiconic sensilla (Fig. 3B). Clypeo-labrum with 10 setae along posterior margin in holotype, 8-10 in subadult paratypes; anterior margin of labrum with 3-4 lamellar teeth each side of the median cleft; fine sandy granular surface, granules becoming smaller posteriorly (Fig. 3D). Lateral palp of gnathochilarium typical of the genus with 13 cylindrical sensilla.

Collum and tergites 2-9 with small median gap in posterior row of trichomes (Fig. 3C). Rows increasingly closer together in posterior tergites. Tergite 10 of holotype damaged so size of median gap unable to be determined. Leg chaetotaxy as follows: coxa 1, 1 seta, coxa 2, 2 setae, coxae 3-13, 2-3 setae; prefemur, tibia, tarsus 2, 1 seta; femur, 2 setae (Fig. 3E). Setae of the coxa, prefemur and distal edge femur with biarticulate setae similar to those for Unixenus mjoebergi with longitudinal ridges on basal funicle, each ridge extending distally in a long, thin spine with the spines surrounding the base of the flagellum (Fig. 3F); seta of mid femur similar but smaller, tibia and tarsus 2 with setiform setae (Fig. 3G); telotarsus bearing anterior spinous projection longer than the claw which bears large anterior process ½ length of claw, no posterior process visible, short lamella process (Fig. 3I). Vulvae of adult female typical of genus, with numerous setae (Fig. 3H). Male with 2 pairs coxal glands on leg pairs 8 and 9.

Telson with ornamental trichome insertions numbering 6-8a, 1b, and 3c each side of the midline, arrangement typical for the genus, as illustrated for Unixenus corringlensis . These trichomes barbate, long and straight. Hooked caudal trichomes with 1-3 hooks on barbed stems, majority with distal facing barbs only along stem proximal to hooks, very small number with distal and proximal facing barbs.

Distribution.

So far known only from three forested sites in northern NSW, with a north-south range of ca 200 km (Fig. 5).