Bicoxidens aridis Mwabvu, 2009

Mwabvu, Tarombera, Hamer, Michelle & Slotow, Robert, 2009, A new species of Bicoxidens Attems, 1928 (Diplopoda, Spirostreptida, Spirostreptidae) from northern Zimbabwe, ZooKeys 7 (7), pp. 75-81 : 76-79

Bicoxidens aridis Mwabvu , sp. n.

urn:lsid:zoobank.org:act:602DFBC1-2D05-4C66-8386-6CF636FA3957

Type material. Holotype: ZIMBABWE: 1 ♁, Mbizi Pan [1628C4], 12. XII. 1983, Putterill G. ( NMZ / D156 ).

Additional material examined. ZIMBABWE: 1 ♁, Nyamapanda [16 o 90' S, 32 o 80' E], XII.1998, Mwabvu T. ( MRAC 20554 ) ; 2 ♁, Mushumbi Pools [1630B1], 22- 25.XI.1997, ( NMZ / D819 ) ; 1 ♁, Chimutsi ( NMZ / D272 ) .

Etymology. Specific name refers to the fact that the species occurs in a dry, low rainfall region.

Diagnosis. Distal telocoxite folded towards apical proplica, producing a hook shape and a median cavity ( Figs 1a, 1b ); lateral margins of proplica and metaplica setose; postfemur of telopodite as long as proplica, with a proximal clockwise coil distal to the femoral lobes, and without looping at the extremity ( Fig. 2 ).

Description

Dimensions. Body length 73-88 mm; minimum and maximum body width 3-4 mm and 3.5-6 mm, respectively; antenna length 4-5 mm, extending up to the 3 rd body ring; leg length 3-4 mm.

Number of body rings. 54-56.

Colour. Body light to dark brown; head light brown; antennae dark brown to black; posterior part of metazonite dark brown or black; prozonite cream; legs light brown.

Gnathochilarium. With long setae along distal margin of the stipes and lingual lamella; one small papilla behind and between the larger two.

First ozopore. On 6 th body ring close to or on sigilla row.

Collum. Anterior corner rounded or square in shape, not produced into a lateral lobe, with 2-6 submarginal folds ( Fig. 1c ).

First pair of legs. Tarsal claws straight, but gently curved apically; prefemoral processes proximally parallel, but not touching medially, with laterally directed nipple-shaped apical lobes that are widely separated distally ( Fig. 1d ).

Sigilla. One row of large circles.

Midbody ring. Diameter of metazonite greater than prozonite, prozonte with up to 16 striae that are further apart posteriorly; limbus with straight edge.

Gonopod. ( Figs 1a, 1b , 2) 4 mm long, with a triangular sternite; paracoxite rounded apically and basally fused to metaplica. Distally, metaplica of telocoxite hook shaped, laterally rounded and folded towards and overhanging apical region of proplica of telocoxite forming a median cavity ( Figs 1a, 1b ). Lateral margins of proplica and metaplica setose. Orally proplica with an apical heart-shaped lobe which conceals the telopodite at the knee ( Fig. 1a ).

Proximal half of telopodite broader than distal (postfemoral) half. Length of postfemoral region of telopodite equal to that of proplica. Telopodite bends laterally and produces a tight clockwise coil distal to the femoral lobes, above level of the paracoxite

( Figs 1a , 2b). Postfemur of telopodite extends distally towards the telocoxal apex and crosses the post knee part proximal to the coil and femoral lobes ( Fig. 1a ). Telopodite without apical looping, but with two unequal lobes at the extremity ( Fig 2a ).

Distribution. Appears to be widespread in the Zambezi Valley and northern Zimbabwe, a dry savanna region characterised by high temperatures and low, unreliable rainfall ( Nyamapfene, 1991).

Figures

Figure 1. Bicoxidens aridis sp. n. A, oral view of gonopods; B, aboral view of gonopods; C, lateral view of collum; D, oral view of prefemoral lobe of first pair of male legs. Abbreviations: p, proplica; hsl, heartshaped lobe; m, metaplica; mc, median cavity; tp, telopodite; tpc, telopodite coil; mf, metaplica fold; cf, collum fold; pfl, prefemoral lobe; pc, paracoxite.

Figure 2. B. aridis sp. n. A, telopodite apex; B, telopodite coil. Abbreviations: tp, telopodite; fl, femoral lobe, tpc, telopodite coil; tpal, telopodite apical lobe.