Afraustraloxenodes coineaui, 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 : 78-81

Afraustraloxenodes coineaui sp. n.

( Figs 21–40 )

Etymology: This species is named for its collector, Prof. Yves Coineau.

Type material: Holotype adult female; paratypes: two adult females, one adult male, one female with 10 pairs of legs ( MNHN), one adult female ( SMWN), NAMIBIA: Hamilton Range , on top of marble mountain, in cracks of rocks, under stones, 24.x.1991;

two adult females ( MNHN), same place, 9.xi.1991 ; one female with 12 pairs of legs ( MNHN), same place, 9.xii.1993 ; one adult male ( MNHN), same place, 14.xii.1993 ; two adult males, one adult female and one male with 12 pairs of legs ( MNHN), same place, 12.iii.1981 , all Y. Coineau. Of the specimens mounted on slides, the holotype, two female paratypes (nos 1 and 2) and one male (no. 3) (almost moulting) have been described.

Other material examined: one adult male ( MNHN), NAMIBIA : Swartbank , 40 km North-West of Gobabeb, 13.iii.1991?, M. Seely ; one adult female ( MNHN), NAMIBIA : Mirabib Rock , 26.x.[year?], Y. Coineau ; one adult female and one male with 12 pairs of legs (Coll. Prof. Condé, Nancy), ANGOLA ,1962.

Description of adults:

Coloration: Females from Angola and Mirabib Rock brownish with brown trichomes. All individuals from Hamilton Range ( Fig. 21 ) and from Swartbank whitish with white or beige trichomes, some specimens showing slight pigmentation between ocelli.

Measurements: Body length (without caudal penicil): holotype 3.60 mm; females nos 2 and 3 4.10 mm; male 3.0 mm; female from Angola 2.80 mm. Length of caudal penicil: 0.90 mm in female no. 3. Length of tarsus II of 13th leg: 130 m. (holotype and female no 2), 135 m (female no. 3 and female from Angola), 100 m (male).

Head: Eight ocelli on each side. Vertex with one pair of posterior tufts consisting of two rows: anterior row with nine to 11, posterior row with nine to 13 trichomes, the posteriormost being slightly behind trichobothria. Towards middle of vertex, two anterior rows not separated from anterior tufts of vertex. Distance between each tuft small ( Fig. 22 ). Proportions of antennal articles as in Fig. 23 . Article VI twice as long as diameter, with three thick dorsal sensilla basiconica: anterior slightly shorter than two subequal posterior ones ( Fig. 25 ). One setiform sensillum between anterior sensilla, and a posterior sensillum basiconicum. One posterior sensillum coeloconicum.Antennal article VII with two dorsal sensilla basiconica: posterior one slightly shorter than anterior; one posterior sensillum coeloconicum and one setiform sensillum between two sensilla basiconica ( Fig. 24 ). Three trichobothria of equal size, each with cylindrical funiculum. Surface of labrum with numerous flat papillae enclosing small granules ( Fig. 27 ); two or three anterior rows of papillae larger. 5+5 lamellate teeth at anterior margin, except male with 4+4. Clypeo-labrum with eight to 10 setae along posterior margin. Outer palp of gnathochilarium with 12 or 13 pseudoarticulated sensilla apically, middle palp with 20 or 21 sensilla, comprising 13 or 14 long pseudoarticulated sensilla and seven short non-articulated sensilla ( Figs 26, 28 ).

Trunk: Except on tergites VIII or IX to X, trichomes arranged in three rows and two lateral tufts. Each paired tuft connected by posterior row of trichomes running along posterior margin of tergite; both more anterior rows with a few trichomes spaced apart. In posterior row shorter trichomes alternating with longer trichomes ( Fig. 29 ). Total number of trichomes on tergites as follows: I (collum), 56 to 71; II to VIII, 72 to 127. Lateral protuberance of tergite I with three to five trichomes in a row.

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 32, 33 ). Chaetotaxy as follows: coxa I with one seta, II to XIII with two setae except VIII and IX in male (one seta and two or three small setae at edge of opening of coxal glands); trochanter, femur and tibia with one seta ( Figs 34, 36 ); prefemur with one oval-based seta plus, on II to XIII, one or two (three in two cases) small aligned setae. Coxa, femur and tibia XIII without setae in male. Second tarsus with a small seta ( Fig. 35 ). Pretarsus bearing anterior process with a spinal projection slightly shorter than claw, two subequal latero-anterior and posterior spiniform processes, and a posterior lamellate process thickened and pleated at base ( Figs 30, 31, 37, 38 ).

Male: All areas of penis with cuticular setae and a dozen small setae. Coxal glands on legs VIII and IX.

Telson : Four to five setae above anal valve ( Figs 39, 40 ) of which two external ones with a raised base ( Fig. 40 ), two in male, both also with elevated base. Dorsal trichomes of telson consisting of five to eight (females) and two to three (males) trichomes (a) varying on different sides (5+ 4 in holotype), one trichome (b) antero-internal of each group of 6 to 9 trichomes (c). Trichomes of caudal penicil generally with three or four hooks (rarely two or five).

Remarks: A different coloration is observed in specimens from Hamilton Range and Swartbank on the one hand, and Mirabib Rock and Angola on the other hand. The original locality of the specimen from Angola is unknown. The other specimens are from the Namib Desert found at three localities: (1) Hamilton Range where the white A. coineaui occured under rock on the top of a white marble mountain, (2) Swartbank, 40 km North-West of Gobabeb, on limestone and laterite where the individuals are white too, and (3) more easterly, granitic Mirabib Rock where the female collected is brownish with brown trichomes.

Transpiration measurements were carried out using a female of A. coineaui from Hamilton Range by Dr Vannier (pers. comm.) with a thermostatic incubator and a programmed regulator allowing air temperature to elevate from 20 C to 90 C, at a rate of 0.5 C/min., in dried air. The female weighed 1.37 mg and its thermotorpor point was 59.6 C. In comparison the thermotorpor point of some females of P. lagurus (bisexual form) from the Paris region varied from 55.2 C to 55.7 C. These preliminary investigations show that A. coineaui seems highly resistant to heat and dryness.

Figures

Fig. 21. Afraustraloxenodes coineaui sp. n., paratype. Adult male in extention, habitus, dorsal view.

Figs 22–28. Afraustraloxenodes coineaui sp. n. 22. Adult female from Angola, head, dorsal view. 23–26. Holotype, adult female. 23. Left antenna. 24–25. Sensilla of articles VII and VI of the same antenna. 26. Left palp of gnathochilarium. 27–28.Adult female from Mirabib. 27. Labrum, interior granules only represented in a few papillae. 28. Left palp of gnathochilarium. Scale bars: Figs 24, 25, 27 = 25 m; other figures = 50 m.

Figs 29–40. Afraustraloxenodes coineaui sp. n. 29–31.Adult female from Mirabib. 29. Trichomes of tergite III. 30. Telotarsus of right leg III, antero-internal view. 31. Telotarsus of right leg II, posterior view. 32–40. Holotype, adult female. 32–33. Setae on coxa leg III and prefemur leg IV. 34–36. Small setae on femur of leg III, on tarsus II of leg XII, and on tibia of leg III. 37–38. Right telotarsi of leg III and leg IV, posterior view. 39–40. Internal and external setae above left anal valve. Scale bars: Fig. 29 = 50 m; other figures = 25 m.