Paredrodesmus australis, Mesibov, Robert, 2003

Mesibov, Robert, 2003, Two new and unusual genera of millipedes (Diplopoda: Polydesmida) from Tasmania, Australia, Zootaxa 368, pp. 1-32 : 13-14

Paredrodesmus australis n. sp.

Figs. 6 , 8 , map Fig. 12 B

Holotype: Male , Coopers Creek, DN507635 (42°46’45”S, 146°23’50”E), 460m, 23.ii.1994, R. Mesibov, QVM 23 :41168.

Paratypes: Male, details as for holotype, AM KS86290 ; male, Kallista Creek , DN625651 (42°45’56”S, 146°32’30”E), 300m, 21.ix.2002, R. Mesibov, QVM 23 :25464.

Other material examined: 3 males. See Appendix for details.

Diagnosis: Distinguished from other Paredrodesmus by the unique form of the gonopod.

Description: As for the genus. Males 10–11 mm long, 0.8–0.9 mm in maximum vertical diameter. In alcohol, well­coloured adults are pale with reddish mottling on distal anntennomeres and metazonites, notably around ozopores. Antennal bases separated by ca. 1.25 times a base diameter, antennomere 6 about one and a quarter times the width of 5. Legpairs 6 and 7 with a wide gap between opposing coxae, legpair 5 with a narrower gap; flexed gonopods reach to the gap between legpairs 5 and 6. Genital opening on leg 2 coxa on a prominent mesal projection ( Fig. 6 A). Gonopod aperture with rear margin raised in the middle. Telopodites ( Fig. 8 ) closely pressed together but not fused, the contact surfaces flat, the outer surfaces rounded. Telopodite base broad with a few short and long setae; distal portion of telopodite arising medially, curving caudad at about half its length and expanding to a broad tip with slightly rounded distal surface, the very small, bluntly pointed solenomerite arising in the middle of this surface. The prostatic groove runs along the mesal surface of the telopodite before abruptly turning laterad across the broad top of the telopodite to the solenomerite. A comb of ca. 50 variably long, peg­like structures arises from a line circling the edge of the telopodite tip and extending proximad along the anteromesal surface. The comb can be divided into two sections according to peg orientation: directed proximad and laterad on the posterior edge of the telopodite tip, laterad elsewhere.

Distribution and habitat: In well­rotted litter, humus and richly organic soil over ca. 600 km 2 in south central Tasmania from 80 m to ca. 600 m, in wet eucalypt forest and Nothofagus rainforest ( Fig. 12 B). Co­occurs with P. b i c a l c a r. This is an uncommon species whose known range is likely to increase with further sampling.

Etymology: Latin australis , southern, adjective. This species is restricted to southern Tasmania.

Figures

FIGURE 6. Antennae and legs of Paredrodesmus spp. males. All drawings to same scale, apical cones and setation not shown. (A) Leg 2 of (left to right) P. aceriodendron n. sp., QVM 23: 41165, P. australis n. sp., QVM 23: 41167, P. b i c a l c a r n. sp., QVM 23: 41178, P. monticolus n. sp., QVM 23: 41155, P. p u r p u re u s n. sp., QVM 23: 41524 and P. taurulus n. sp., QVM 23: 41132; (B) antennae of (left) P. b i c a l c a r n. sp., QVM 23: 41178 and (right) P. aceriodendron n. sp., QVM 23: 41165; (C) leg 9 of P. purpureus n. sp., QVM 23: 41524; (D) leg 3 and sternal projection of P. taurulus n. sp., QVM 23: 41132; (E) leg 1 (left, posterior view) and leg 3 and sternal projection (right) of P. b i c a l ­ car n. sp., QVM 23: 41178.

FIGURE 8. SEM views of Paredrodesmus gonopods in situ. (Left) P. australis n. sp., QVM 23: 41169; anterior to right, scale bar = 0.5 mm. (Right) P. bicalcar n. sp., QVM 23: 41178; anterior to right, scale bar = 0.35 mm, ‘ s’ = solenomerite.

FIGURE 12. Distributions in Tasmania of Paredrodesmus spp. (A) P. aceriodendron n. sp. (large squares) and unidentified Paredrodesmus females and juveniles (small squares); (B) P. taurulus n. sp. (squares) and P. australis n. sp. (crosses); (C) P. b i c a l c a r n. sp. (squares); (D) P. monticolus n. sp. (crosses) and P. purpureus n. sp. (squares).