Nepalmatoiulus shiguensis, Mikhaljova, 2024

Mikhaljova, Elena V., 2024, New species and new records of millipedes of the genera Nepalmatoiulus Mauriès, 1983 and Anaulaciulus Pocock, 1895 (Diplopoda, Julida, Julidae) from mainland China, Zootaxa 5447 (4), pp. 496-512 : 505-507

Nepalmatoiulus shiguensis sp. nov.

Figs 31–39

Material examined. Holotype: 1 male ( ZMUM), China, Yunnan Province, Laojunshan , W Shigu, W Wujiangshui , 26°52'14" N, 99°41'43" E, H = 2740 m, 2.06. 2014, leg. I. Belousov, I. Kabak. Paratypes: 1 male, 1 female ( ZMUM), same data as for holotype .

Diagnosis. Differs from Chinese congeners mainly by the male coxa 2 with two mesapical oral setae anteriorly and three ones posteriorly, in combination with a large body size and the coloration pattern, a small mesal projection of gonopod promere apex and a relatively long solenomere. Configuration of gonopod opisthomere in N. shiguensis sp. nov. similar to Nepalmatoiulus angustus Mikhaljova, 2023b , N. tianbaoshanensis Mikhaljova, 2020a and N. davidiani sp. nov. but differs from them by specific characters (see Remarks below).

Description. Male. Length in alcohol 34.0–36.0 mm, midbody vertical diameter about 2.6 mm, with 59(-1) (in holotype) and 58(-1) (in paratype) rings, excluding telson. The coloration in alcohol brown-gray with dark brown thin lateral stripes and adjacent longitudinal thin blurred beige stripes. Venter including basal parts of legs light beige. Distal parts of legs marbled brown. Antennae dark brown, eyes black.

Head smooth, 2 epicranial setae, 4 supralabral setae; at least 30 labral setae. Eye patches almost oval, composed of at least 50 ommatidia.Antennae medium-sized, rather slender and clavate.Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica. Mandibular stipites with subtriangular smooth lobes; apical portion of lobe with well demarcated brown border. Gnathochilarium with 7–8 nonapical stipital setae; lamellae linguales each with 6–7 setae arranged longitudinally. Collum laterally with distinct striae at posterior margin nearly reaching to anterior margin, dorsally with distinct short striae at posterior margin. A transverse row of sparse thin setae at hind edge of collum.

Body rings circular. Metazona with dense, regular, longitudinal striae reaching hind margin (16–18 striae in an approximate square with sides equal to metazonital length of a dorsal side of a midbody ring). Limbus straight, smooth (of Type 1 in Enghoff 1987). A transverse row of sparse, thin setae at hind edge of metazonites, setae gradually growing denser and longer toward telson. Ozopores small, lying behind suture between pro- and metazona without touching it. Telson with caudal dorsal projection straight and long, covered with setae and carrying at tip a claw-shaped process curved dorsally. Preanal ring, anal valves, and subanal scale densely setose.

Legs relatively short and slender. Very delicately serrate ventral pads present on postfemur and tibia, starting from legs 2; pads decreasing in size towards telson, totally disappearing on postfemur and remaining only on the most extreme tibial apex of hind legs. Claw of all legs at base with a long setiform accessory claw ventrally. Leg pair 1 forming a hook, the distal podomere not coming into close contact with the basal podomeres (“open hook” type in Enghoff 1987); postfemur with inflated scaly-rugose ventral surface, tip indistinctly wrinkled, coxa with one seta, distal podomere with strong seta laterally ( Fig. 33 ). Coxa 2 with two long mesapical oral setae anteriorly ( Fig. 32 ) and three ones posteriorly ( Fig. 31 ), gland opening positioned in apical and axial position sensu Enghoff (1987). Penis subtrapezoidal, about 1.7 times longer than wide ( Fig. 35 ).

Gonopods slightly protruding. Promere flattened, with parallel margins, apically slightly obliquely rounded, in posterior view apically excavated for accommodation of mesomeral process, distal margins of the excavation papillate, rudimentary telopodite with seta ( Fig. 36 ). Flagellum slender, of medium length, caudally covered with cuticular conical spikes ( Fig. 37 ). Opisthomere slender ( Fig. 38 ); mesomeral process slightly arched forward, its apex covered with papillae. Velum narrow, its margin smooth, arcuate, with a notch near the mesomeral process. Additional membrane with a serrate edge. Solenomere long, spinose throughout, basally with blade (bb) ( Fig. 39 ).

Female. Length in alcohol about 35.0 mm, midbody vertical diameter about 2.5 mm, with 55(-1) rings, excluding telson. Dorsal projection of the preanal ring short, underdeveloped, deformed. Vulva as in Fig. 34 .

Etymology. The specific epithet refers to the type locality, Shigu. Adjective.

Remarks. Nepalmatoiulus shiguensis sp. nov. differs from N. tianbaoshanensis mainly by the male coxa 2 with two mesapical oral setae anteriorly and three ones posteriorly (vs. one mesapical oral seta anteriorly in N. tianbaoshanensis ), by the subtrapezoidal penis (vs. nearly diamond-shaped penis in N. tianbaoshanensis ), by the more slender opisthomere, by the mesomeral process located at about an angle 45˚ (vs. mesomeral process located almost vertically in N. tianbaoshanensis ), by the less rounded apex of the promere as well as by a lower habitat above sea level.

Nepalmatoiulus shiguensis sp. nov. differs from N. angustus mainly by the male leg pair 1 with strong seta laterally on the distal podomere (vs. male leg pair 1 without seta laterally on the distal podomere in N. angustus ), by the male coxa 2 with two mesapical oral setae anteriorly and three ones posteriorly (vs. two mesapical oral setae anteriorly only in N. angustus ), by the less rounded apex of the promere, by the larger body.

Nepalmatoiulus shiguensis sp. nov. differs from N. davidiani sp. nov. mainly by the larger body length (34.0– 37.0 mm) and midbody vertical diameter (about 2.6 mm) (vs. length—about 18.0 mm, midbody vertical diameter— about 1.4 mm in N. davidiani sp. nov.), by the coloration of rings below ozopore level not of an usual julid type (after Enghoff 1982), by the male coxa 2 with two mesapical oral setae anteriorly and three ones posteriorly (vs. one mesapical oral seta anteriorly and two ones posteriorly in N. davidiani sp. nov.), by the less obliquely rounded apex of the promere, by a slightly more stronger apex of opisthomere.

Figures

FIGURES 31–35. Nepalmatoiulus shiguensis sp. nov., male and female (Fig. 34) paratypes (ZMUM). 31. Coxae 2, posterior view. 32. Coxae 2, anterior view. 33. Leg 1, anterior view. 34. Vulva, posterior view. 35. Penis, posterior view. Scales: 20 μm (Figs 31, 33, 35), 100 μm (Figs 32, 34).

FIGURES 36–39. Nepalmatoiulus shiguensis sp. nov., male paratype (ZMUM). 36. Right promere, posterior view. 37.Apex of flagellum. 38. Opisthomere, mesal view. 39. Solenomere, mesal view. Abbreviation: bb, basal blade. Scales: 10 μm (Fig. 37), 20 μm (Fig. 39), 100 μm (Figs 36, 38).