Obelostreptus nakitawa ( Silvestri, 1907 ) Mwabvu & VandenSpiegel, 2015

Mwabvu, T. & VandenSpiegel, D., 2015, A review of the genus Obelostreptus Attems, 1909 (Diplopoda, Spirostreptida, Spirostreptidae) with the description of a new species from Kenya, African Invertebrates 56 (1), pp. 51-51 : 56-59

Obelostreptus nakitawa ( Silvestri, 1907) comb. n.

Fig. 4A–F

Archispirostreptus nakitawa Silvestri, 1907: 4–5 (D); 1909: 26, Abb. 55–60 (+D).

Mardonius nakitawa: Attems 1914: 138 (C); Brölemann 1920: 105, Taf. 7, Abb. 32 (N); Attems 1950: 210 (C); Attems 1953: 117 (C); Krabbe 1982: 156.

Obelostreptus oligozonus Attems, 1927: 78 , Abb. 43, 44 (D); Attems 1937: 15 (C).

Globanus leviceps Attems, 1934: 189 , Abb. 37–39 (D).

Archispirostreptus nakitawa: Demange 1970: 367 (C).

Description (Gatamaiyo specimens):

Adult male with 41 body rings, length ± 37 mm, maximum diameter c. 4 mm.

Body colour dominantly brownish, slightly lighter ventrally; prozonite yellowish brown, metazonite with an anterior part brownish and a posterior part dark brown. Antennae and legs yellowish brown. Ozopores visible as blackish spots through cuticle and the succession of these spots gives an impression of a continuous line.

Eyes with c. 24 ocelli in five rows. No frontal setae, four supralabral setae in a transverse row, a row of labral setae, labrum tridentate. Stipes of the mandible with a small ventral lobe. Gnathochilarial stipites with one medio-apical tuberculate of four apico-lateral setae.

Length of antennae 66 % of the diameter of midbody rings. Antennomeres 5 and 6 with an apical sensory pit, four apical sensory cones.

Collum large and smooth. Body roughly cylindrical, diameter decreasing slightly towards posterior; body rings circular to slightly compressed (height/width ratio 106% of midbody ring). Prozonites smooth. Suture between prozonite and metazonite discrete. Lower side of metazonites with metazonital striae extending up to the level of ozopore. No metazonital setae. Ozopore up to ½ metazonite length, behind suture on midbody rings.

First pair of male legs as shown in Fig. 4A , coxae broadly in contact medially; prefemora with small basal projection on anterior side and a few apical setae.

Gonopod coxite rounded distally ( Fig. 4B ), telopodite with an antetorsal process arising just before the major curvature, a laminated postfemoral lobe arising just after the major curvature and a small tarsal process ( Fig. 4C ).

Female longer and wider than male; first pair of legs unmodified; vulva simple, placed vertically in a pouch behind coxosternite of second leg; no vulval setae, aboral valve and oral valve of similar size ( Fig. 4F ).

Material examined: DEMOCRATIC REPUBLIC OF CONGO: 1♂ Mongbwalu (01°57'N 30°02'E),1938, Scheitz ( MRAC 3.760 ) ; 1♂ Mahunga , Ruwenzori (00°20'N 29°50'E), 9.viii.1937, J. Bredo ( MRAC 5.623 ) ; RWANDA: 1♂ Nyongwe , Rugege forest (02°30'N 29°12'E), 2000 m, 6–10.viii.1949, Laurent ( MRAC 5.269 ) ; KENYA: 30 specimens Central Province , Mt. Kenya, face W., Naro Moru Track, 2400 m, G. Coulon ( MRAC 14.163 ) ; 5♂ 9♀ Gatamaiyo Indigenous Forest , in rotten wood, D. VandenSpiegel & Ch. Lange ( MRAC 22544 ) ; 3 specimens Gatamaiyo Indigenous Forest , in rotten wood, D. VandenSpiegel & Ch. Lange ( MRAC 22545 ) ; 12 specimens Gatamaiyo Indigenous Forest , in rotten wood, D. VandenSpiegel & Ch.Lange ( MRAC 22546 ) ; 1♂ 1♀ Gatamaiyo Indigenous Forest , in rotten wood, VandenSpiegel D. & Ch. Lange ( MRAC 22547 ) ; 1♂ 2♀ Gatamaiyo Indigenous Forest , in rotten wood, D. VandenSpiegel & Ch. Lange ( MRAC 22548 ) ; 1♀ Gatamaiyo Indigenous Forest , in rotten wood, D. VandenSpiegel & Ch. Lange ( MRAC 22549 ) .

Distribution: The holotype was collected from Nakitawa, Bihunga , on the border between Uganda and the Democratic Republic of Congo. This species has a large distribution, occurring in the eastern Democratic Republic of Congo, Uganda, Rwanda and now Kenya. Recent records (from Gatamaiyo forest) suggest that the species is more widespread, with the distribution extending eastwards into central Kenya.

Remarks:The telopodite of this species is consistent with the definition of Obelostreptus as demonstrated by the position (just before the major curvature of the telopodite), structure and orientation of the antetorsal process.

Figures

Fig. 4. Obelostreptus nakitawa: (A) first pair of legs of male, anterior view; (B) left gonopod without telopodite,posterior view;(C) left telopodite,posterior view;(D) drawing ofright telopodite, anterior view; (E) drawing of gonopods, right without telopodite, anterior view; (F) right vulva, lateral view. Scale bars = 100µm. Abbreviations: ant – antetorsal process, lav – lobe of aboral valve, lb – lobe, me – metaplica, op – opercule, pp – primary posttarsal process, pr – proplica, slm – solenomerite, tp – telopodite.