Spirostreptus heros Porat 1872

Figs 1, 7 a

Spirostreptus heros Porat 1872, p. 29; Hoffman et al. 2001; Mwabvu 2005a; Hoffman 2008 Spirostreptus triodus Attems 1909, p. 46, figs 76–79.

Triaenostreptus triodus: Attems 1928; Hoffman 1971, 2008; Krabbe 1982; Hamer 1998; Hoffman et al. 2001

Type material: Holotype: BOTSWANA: 1 3, Kalahari [22 0 36'S, 23 0 34'E], (ZMB 4968).

Additional material examined: BOTSWANA: 1 3, 1 Ƥ, Gemsbok National Park, Kalahari [22 0 36'S, 23 0 34'E], 20.iv.1970, B. Lamoral (NMSA 16152); 1 3, 1 Ƥ, Kalahari [22 0 36'S, 23 0 34'E], 2005, (NMSA 20570). SOUTH AFRICA: North West Province: 2 3, Malopo [25 0 43'S, 24 0 17'E], 13.i.2001, R. Slotow & M. Hamer (NMSA 20495, 20498). Northern Cape Province: 1 3, 1 Ƥ, Northern Cape [27.697 0S, 21.355 0E], (NMSA 20551); 1 3, Northern Cape [27.697 0S, 21.355 0E], (NMSA 20495). NAMIBIA: 2 3, 5 Ƥ, Okawango [18 0 18'S, 19 0 15'E], 29.iii.2002, G. Plotner (ZMB 13737, 13738, 13739 & 13742). ZIMBABWE: 1 3, Beitbridge [22 0 02'S, 30 0 00'E], (NMZ/D835).

Diagnosis: Lateral and medial edges of proplica parallel; proplica without abrupt widening subapically; angle between lateral lobe and distal lobe equal to or less than a right angle; antetorsal process S-shaped (Figs 1 a, 1b, 7a).

Description: Size: Body length 184–344 mm; minimum and maximum body width 8–14.5 mm and 13.5– 19 mm; antenna length 10–13 mm.

Number of body rings: 59–68.

Colour: Body black; legs and antennae black or dark brown.

Collum: Anterior produced laterally into a narrow lobe, with 2–5 complete folds and 0–3 incomplete folds (Fig. 1 d).

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

Gonopod: (Figs 1 a, 1b) 7–9 mm long; telocoxites parallel, but not in contact.

Sternite short, wide and apex not extending distally to level of paracoxite apex.

Proplica tapering apically. Apex of proplica conceals proximal lateral lobe. Proplica does not overlap distal lobe (Fig. 1 a).

Metaplica without lobes or humps, wider proximal to telopodite knee (Fig. 1 b).

Lateral lobe extends beyond lateral edges of proplica and distal lobe. Aborally, lateral lobe proximally narrow, rounded distally (Figs 1 a, 1b).

Distal lobe laterally and apically rounded; medial edge of distal lobe concave, forming a shallow invagination. Surface of distal telocoxite lobe smooth; distal lobe not extending beyond lateral edge of proplica apex (Fig. 1 a). Orally, the distal lobe may have a shallow central depression.

Telopodite with antetorsal process which extends past paracoxite, post-knee telopodite with an open coil. Antetorsal process S-shaped (Figs 1 a, 1b, 7a).

Distribution: Known from southern Botswana, north-western South Africa, northern Namibia and southern Zimbabwe.

Remarks: The smooth surface texture and shape of the distal lobe of the gonopods resemble the form in batokensis, unciger and kruegeri rather than sebae and tripartitus .

The gonopods of heros and kruegeri are the most similar. However, in heros the angle between the lateral lobe and distal lobe is equal to or less than a right angle while in S. kruegeri it is wider. Additionally, in heros the lateral edge of the proplica is straight, without abrupt widening subapically while in kruegeri the proplica is wide subapically. The antetorsal process in heros is S-shaped unlike in kruegeri where it is concave (Figs 7 a, 7b). The distal nipple on the lateral lobe in some specimens of kruegeri has not been observed in heros . In addition, the medial edges of the telocoxites are straight and largely parallel along the whole length in heros as opposed to kruegeri where they are widely separated at the level of the lateral lobe (Figs 1 a, 2a).