Spirostreptus batokensis Mwabvu

Mwabvu, Tarombera, Hamer, Michelle, Slotow, Robert & Barraclough, David, 2009, A revision of the taxonomy and distribution of Spirostreptus Brandt 1833 (Diplopoda, Spirostreptida, Spirostreptidae) with descriptions of a new species and a new genus of spirostreptid millipede, Zootaxa 2211, pp. 36-56 : 48-49

Spirostreptus batokensis Mwabvu , sp. n.

Figs 6 , 7 e

Type material: Holotype: ZIMBABWE: 1 3, Batoka Gorge [1726C3], 28.vii.1995. F. Nyathi (NMZ/D835).

Etymology: Refers to the type locality, Batoka Gorge, Zimbabwe.

Diagnosis: Distal lobe subtriangular ( Fig. 6 a).

Description: Size: Body length 215 mm; minimum and maximum body width 6 mm and 13 mm; antenna length 11 mm.

Number of body rings: 60.

Colour: Body black; legs and antennae black.

Collum: Anterior slightly produced into a short rounded lateral lobe, with 4 complete folds and 3 incomplete folds ( Fig. 6 d).

Pre-femoral process of 1st pair of male legs: Proximally rounded, medial nipples distally narrow and strongly deflected laterally ( Fig. 6 c).

Gonopod: 6 mm long; telocoxites parallel, but separated.

Sternite apex not reaching the level of paracoxite apex.

Proplica wider subapically and tapering apically. Apically proplica concealing the proximal lateral lobe. Proplica not overlapping the distal lobe ( Fig. 6 a).

Metaplica with humps, wider proximal to telopodite knee ( Fig. 6 b).

Lateral lobe slanting steeply, not extending beyond the lateral edge of the distal lobe or widest part of proplica. Aborally, lateral lobe proximally wide; rounded distally ( Figs 6 a, 6b).

Distal lobe rounded and narrow apically, proximally wider than apex (subtriangular), surface of distal telocoxite lobe smooth with a depression; proximal distal lobe width not extending beyond lateral edge of subapical proplica ( Fig. 6 a).

Telopodite with short crescent-shaped antetorsal process; antetorsal process not reaching paracoxite apex; post knee telopodite with an open coil ( Figs 6 a, 6b, 7e).

Distribution: Known only from type locality near Victoria Falls in western Zimbabwe.

Remarks: Like congeners this species has a laterally rounded distal lobe. Although the gonopod is smaller (approximately the same size as that of sebae and tripartitus ), the surface texture of the distal telocoxite lobe resembles more closely that of heros , unciger and kruegeri than sebae and tripartitus . The subtriangular shape of the distal lobe distinguishes batokensis from the congeners ( Fig. 6 a).

Figures

FIGURE 6. Spirostreptus batokensis (NMZ / D 585). a, oral view of gonopods; b, aboral view of gonopods; c, oral view of prefemoral lobe of first pair of male legs; d, lateral view of collum. Abbreviations: p, proplica; m, metaplica; llb, lateral lobe; dl, distal lobe; d, depression; tp, telopodite; at, antetorsal process; pc, paracoxite; st, sternite; cf, collum fold; al, anterior lobe; pfl, prefemoral lobe.

FIGURE 7. Shape of antetorsal process of the telopodites of Spirostreptus species. a, S. heros; b, S. kruegeri; c, S. sebae; d, S. unciger; e, S. batokensis; f, S. tripartitus. Abbreviations: tp, telopodite; tk, telopodite knee; at, antetorsal process.