Paredrodesmus purpureus, Mesibov, Robert, 2003

Mesibov, Robert, 2003, Two new and unusual genera of millipedes (Diplopoda: Polydesmida) from Tasmania, Australia, Zootaxa 368, pp. 1-32 : 17-19

Paredrodesmus purpureus n. sp.

Figs. 6 , 10 , map Fig. 12 D

Holotype: Male , Pelverata Falls, EN 112325 (43°03’35”S, 147°08’15”E), 6.iv.2003, K. Bonham, QVM 23 :25460.

Paratypes: Male, Macgregor Peak, EN769413 (42°58’36”S, 147°56’35”E), 550m, 9.x.1999, K. Bonham, D. Hird & A. Thompson, AM KS86293 (formerly QVM 23:41225 ); four females, Huon River (Arve Road) , DN798283 (43°05’51”S, 146°45’06”E), 210m, 16.v.1997, R. Mesibov, QVM 23:41216 , plot 3R1 .

Other material examined: 3 males, 27 females and 13 juveniles. See Appendix for details.

Diagnosis: Distinguished from other Paredrodesmus by purple colouration and 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 finely mottled purple apart from nearwhite head, proximal antennomeres, legs and epiproct. Antennal bases separated by ca. 1.5 times a base diameter, antennomere 6 about one and a quarter times the width of 5. Waist more pronounced than in other Paredrodesmus . Legpairs 6 and 7 with a wide gap between opposing coxae, legpairs 4 and 5 with a narrower gap, legpair 3 with a small gap, legpair 3, 4 and 5 gaps filled with dense brushes of setae; flexed gonopods reach to legpair 5. Genital opening on leg 2 coxa on a small mesal projection ( Fig. 6 A). Gonopod aperture with rear margin raised in the middle. Telopodite ( Fig. 10 ) with base block­like with a few short setae, the posterolateral corner of the distal surface of the base projected distally and bearing two long setae. Distal portion of telopodite arising on the anterior side of the base, subcylindrical, expanding distally and slightly curving posterolaterally into a rounded, clublike tip. Arising just proximal to the apex on the anteromesal surface is a flat, S­shaped, mesally directed process, with the very small, bluntly pointed solenomerite (‘s’ in Fig. 10 ) arising just posterior to the base of the S­shaped process. The prostatic groove runs more or less directly to the solenomerite on the mesal side of the telopodite. Anterolaterally on the telopodite are two separate combs of variably long, peg­like structures: a subterminal group of ca. 20 pegs directed posterolaterad and proximad, and a more proximal group of ca. 25 pegs closely pressed to the telopodite and directed proximad; the line of origin of the latter group arises at about two­thirds the length of the telopodite on the anterior surface and curves laterad.

Distribution and habitat: In well­rotted litter, humus and richly organic soil over ca. 2500 km 2 in southeastern Tasmania including Bruny Island, from 60 m to ca. 550 m, mainly in wet eucalypt forest and Nothofagus rainforest ( Fig. 12 D). Co­occurs with P. a c e ­ riodendron in the east of its range and possibly overlaps with P. bicalcar in the west. This is an uncommon species with a low male/female ratio.

Etymology: Latin purpureus , purple, adjective, referring to the colour of the live animal.

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 10. SEM view of Paredrodesmus gonopods in situ, anterior to left. (Left) P. monticolus n. sp., QVM 23: 41158; scale bar = 0.5 mm. (Right) P. purpureus n. sp., QVM 23: 41525; scale bar = 0.45 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).