Drepanura polychaeta sp. nov.

Figs 21−35

Types. Holotype: female, Australia, Barrow Island, 20o 45’S 115o 25’E, 2005/2006, collected by S. Callan. Paratype: 6 females, same data as holotype. All deposited in SAM.

Description. Body length up to 2.5mm.

Ground colour yellow in alcohol. Eye patch and antennae blue-black. Anterior and lateral margins of head with dark blue pigment. Blue pigment also present on legs except tibiotarsi. A narrow longitudinal strip present on midline from Th. II −Abd. II. Abd. II −V with irregularly patches (Fig. 21).

Antenna 0.7−0.8 times as long as body. Antennal segmental ratio in length as I:II:III:IV = 1:1.4−1.7:1.1−1.7:1.5−2.6. Dorsal cephalic chaetotaxy with 4 antennal (An1, An2, An3a1, An3), 2 median (M2, M4) and 7 sutural (S0, S2, S3, S4, S 4i, S5, S 5i) macrochaetae (Fig. 22). Eyes 8+8, G and H smaller. Interocular chaetae as p, q, r, s, t or p, q, r, v, s, t, p chaeta larger than others (Fig. 23). Labral and prelabral chaetae as 4/5, 5, 4; prelabral ones ciliate, others smooth; subapical labral papillae 4, each with 3−4 secondary apical spinules (Fig. 24). Labial triangular chaetae as in fig. 25, 3 chaetae present between M and E, all finely ciliate.

Dorsal macrochaetae shown as in Fig 26. Th. II with 2 (m1, m2) macrochaetae in Mm area and 4 (m 4i, m4, m4p, a5) macrochaetae in Ms area. Th. III with 4 (a1, a2, a2a, a3) macrochaetae in Am area and 8(9) (a 4i 2, a 4i, a4, a5, m 5i, m5, rarely a5e, 2 unknown) macrochaetae in As area. Trochanteral organ with 30−33 smooth spiny chaetae (Fig. 27). Tibiotarsus with inner differentiated ciliate chaetae, most distal one on hind leg smooth. Tenent hair thick with tip clavate, 1.2−1.6 × length of inner side of unguis. Unguis with 4 inner teeth, first pair at 0.4 distance from base of claw, and 2 unpaired teeth, first one at 0.7 and distal one at 0.8 distance from base respectively. Unguiculus acuminate with outer edge serrate (Fig. 28).

Abd. IV 4.5−8.5 times as Abd. III in length along dorsal midline. Dorsal macrochaetae shown in Figs 29−30. Abd. I with 19 central and 2−5 lateral macrochaetae on each side. Abd. II with 16−18 central and 5−8 lateral macrochaetae. Abd. III with 1 central (m3) and 3 lateral (am6, pm6, p6) macrochaetae (Fig. 29). Abd. IV with 53−61 central and 27−38 lateral macrochaetae (Fig. 30). Tenaculum with 4 teeth and 1 long ciliate chaeta (Fig. 31). Ventral tube anteriorly with 20 ciliate chaetae of different sizes (Fig. 32), laterally with 8 smooth chaetae and 1 ciliate chaeta (Fig. 33). Manubrial plaque with 5 ciliate chaetae and 2 pseudopores on each side (Fig. 34). Dens without spines, uncrenulated part 1.6−2.3 times as mucro in length. Mucro falcate and tip of basal spine not reaching apex of the tooth (Fig. 35).

Etymology. Named because of the large number of macrochaetae on abdomen.

Remarks. This species is close to the Australian species D. albocoerulea (Schött, 1917) in colour pattern of the abdomen, but the body chaetotaxy is different (Table 1). It is also similar to the Russian species D. montana Martynova & Chikatunov, 1968, but each labral papilla has 3−4 secondary apical spinules in D. polychaeta sp. nov. and only one in D. montana .