Afraustraloxenodes namibiensis, Duy-Jacquemin, 2003

Duy-Jacquemin, Monique Nguyen, 2003, A new genus of Penicillata from Southern Africa with pseudoarticulated sensilla on the palpi of the gnathochilarium (Diplopoda: Polyxenida: Polyxenidae), African Invertebrates 44 (1), pp. 71-88 : 73-77

Afraustraloxenodes namibiensis sp. n.

( Figs 1–20 )

Etymology: The name refers to the terra typica.

Type material: Holotype adult male, allotype adult female; paratypes: seven adult males, one adult female and one subadult male (with 12 pairs of legs) ( MNHN), one adult male ( SMWN), NAMIBIA: towards Rehoboth , on C26 road, 2.5 km before C26-1265 crossroads, under stones, alt. 1760 m, on ledge of rocks, 28.x.1991, Y. Coineau.

Other material examined: One adult male ( MNHN), NAMIBIA: 150 km West of Windhoek , near cross towards south, on rocks, 26.iii.1981, Y. Coineau .

Description of adults:

Coloration: Brownish with darker greyish-brown trichomes, pigmentation indicated in Fig. 1 .

Measurements: Body length (without caudal penicil): holotype 2.70 mm; allotype 3.00 mm; paratypes 2.80 mm (except male no. 5 in extension, 3.30mm). Length of caudal penicil: 0.50 mm. Length of tarsus II of 13th leg, 98 (holotype) to 102 m.

Head: Eight ocelli on each side. Vertex with one pair of posterior tufts consisting of two rows: anterior row with nine (except eight in a male and 10 in a female), posterior row with seven to nine trichomes, last trichome slightly more posterior to trichobothria ( Fig. 2 ). Distance between each tuft small. Proportions of antennal articles as in Fig. 4 ; ratio length/diameter of article VI = 1.50–1.90. Antennal article VI with five dorsal sensilla basiconica: anterior two short and slightly more apical than longer posterior three ( Fig. 6 ); one sensillum coeloconicum between first and last two posterior sensilla basiconica; one setiform sensillum between the two short anterior sensilla. Right antenna of one male with only four sensilla basiconica (one long sensilla missing). Antennal article VII with two dorsal sensilla basiconica: posterior one shorter than anterior; one sensillum coeloconicum posterior and one setiform sensillum between two sensilla basiconica ( Fig. 5 ). Three trichobothria of equal size, with cylindrical funiculi ( Fig. 3 ). Surface of labrum with numerous, small, short-cuspidate papillae; papillae of anterior two or three rows larger ( Fig. 9 ). 5+5 lamellate teeth at anterior margin. Clypeo-labrum with nine to 10 setae along posterior margin. Outer palp of gnathochilarium with 15 or 16 sensilla pseudoarticulated apically; middle palp with 21 sensilla, comprising 14 long pseudoarticulated sensilla and seven short non-articulated at apex ( Fig. 8 ).

Trunk: Except on tergites VIII or IX to X, trichomes arranged in three rows and two lateral tufts ( Figs 18, 19 ). Each paired tuft connected by a posterior row of trichomes (p.r.) arranged along posterior margin of tergite; two more anterior rows (a. r. and m.r.) with a few trichomes spaced apart. In posterior row, shorter trichomes alternating with longer trichomes. Total number of trichomes on tergites as follows: I (collum), 40–47; II to VII, 54–81. Lateral protuberance of tergite I with three or four trichomes in a row ( Fig. 2 ).

Legs: Each article of legs bearing sensory setae, except first tarsus. Coxa, trochanter and prefemur each bearing a seta with an oval base furnished with acute process at apex ( Figs 11, 12 ). Chaetotaxy as follows: coxa I with one seta, coxae II to XIII with two setae, except VIII and IX in male (one seta and three small setae at edge of opening of coxal glands); trochanters with one seta; prefemora with one seta and one or two (one three) small aligned setae ( Figs 10, 13 ); each femur and tibia with same small seta as prefemur, tapered apically. Second tarsus with a small seta as shown in Fig. 14 . Pretarsus bearing anterior process with a spinous projection slightly shorter than claw, two subequal latero-anterior and posterior spiniform processes; posterior lamellate process thickened and pleated basally ( Figs 15, 16 ).

Male: All areas of penis with thin, usual, cuticular setae and nine or 10 small setae ( Fig. 10 ). Coxal glands on legs VIII and IX.

Telson . Four to five setae above anal valve, two external ones with raised base. Bundle of caudal penicil unseparated. On each side of median plate, dorsal trichomes of telson consisting of two or three trichomes (a), one trichome (b) inner to group of 10–11 trichomes (c) (10 in male no. 5, Fig. 17 ). Trichomes of caudal penicil generally with three hooks ( Fig. 20 ), rarely with two or four.

Remarks: The male collected 150 km west of Windhoek differs from the type specimens from around Rehoboth by the complete absence of pigment, by its small size (2.35 mm) and in having six sensilla basiconica on antennal article VI (three long sensilla and three short sensilla in the left antenna: Fig. 7 ; four long sensilla and two short sensilla in the right antenna).

Figures

Fig. 1. Afraustraloxenodes namibiensis sp. n., paratype. Adult female, habitus, dorsal view.

Figs 2–9. Afraustraloxenodes namibiensis sp. n. 2–3. Adult male no. 5. 2. Head and collum, dorsal view. 3. Structural details of right trichobothria. 4–6.Allotype, adult female. 4. Left antenna. 5–6. Sensilla of articles VII and VI of the same antenna. 7. Adult male from near Windhoek, sensilla of right antennal article VI. 8. Adult male no. 2, left palp of gnathochilarium. 9. Male holotype, labrum, papillae only represented on median and left parts. Scale bars: Figs 2, 4, 9 = 50 m; other figures = 25 m.

Figs 10–20. Afraustraloxenodes namibiensis sp. n.10–16. Male holotype. 10. Right leg II and penis. 11–12. Coxal and prefemoral setae of the same leg. 13. Small seta on the same prefemur. 14. Seta on tarsus II of right leg II. 15. Telotarsus of the same leg. 16. Telotarsus of left leg VIII. 17–20. Male no. 5. 17. Telson, dorsal view: a, b and c, barbate dorsal trichomes. 18. Insertions of trichomes on tergite III: a.r. anterior row; m.r. median row, p.r. posterior row. 19. Trichomes on tergite III. 20. Crooked trichome. Scale bars: Figs 10, 17 = 50 m; other figures = 25 m.