Nepalmatoiulus davidiani, 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 : 497-498

Nepalmatoiulus davidiani sp. nov.

Figs 1–9

Material examined. Holotype: 1 male ( ZMUM), China, Yunnan Province, NW of Jianchuan , 10.5 km WNW Shuanghecun, 26°36'59" N, 99°46'34" E, H = 2870 m, 16.05. 2016, leg. I. Kabak, G. Davidian.

Diagnosis. Differs from Chinese congeners mainly by the combination of: male coxa 2 with one and two mesapical oral setae anteriorly and posteriorly, respectively; a strongly obliquely rounded apex of gonopod promere; relatively small body size; colour pattern of the usual julid type (after Enghoff 1982) of rings below ozopore level. Configuration of gonopod opisthomere in N. davidiani sp. nov. similar to Nepalmatoiulus angustus Mikhaljova, 2023b and N. shiguensis sp. nov., but differs from both of them by specific characters (see Remarks below).

Description. Male. Length in alcohol about 18.0 mm, midbody vertical diameter about 1.4 mm, with 53(-3) rings, excluding telson. Coloration in alcohol dark brown with broad longitudinal slightly lighter dorsal stripe; rings below ozopore level, head, collum and pregonopodal rings of the usual julid type (after Enghoff 1982). Venter including basal parts of legs beige. Distal parts of legs marbled brown. Antennae brown, eyes black.

Head smooth, 2 epicranial setae, 4 supralabral setae; at least 24 labral setae. Eye patch almost oval, composed of at least 40 ommatidia in holotype. Antennae medium-sized, rather slender and clavate. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica. Mandibular stipites with subtriangular smooth lobes. Gnathochilarium with about 10 nonapical stipital setae; lamellae linguales each with 5 setae arranged longitudinally. Collum laterally with distinct striae of different lengths at posterior margin, the first of which (the longest striae) reaching to anterior margin, dorsally with distinct short striae at posterior margin. A transverse row of very sparse thin setae at hind edge of collum.

Body rings circular. Metazona with dense, regular, longitudinal striae reaching hind margin (15–16 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 dividing pro- and metazona, set off from the suture on almost all rings, in touch with suture only in the most posterior ones. Telson with caudal dorsal projection straight and long, covered with setae and carrying at tip a claw-shaped process curved dorsad. 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. Claw of all legs at base with a long (longer than claw) setiform accessory claw ventrally. Leg pair 1 forming 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 segment with one seta laterally and minute seta tarsal remnant ( Fig. 1 ). Coxa 2 with one long mesapical oral seta anteriorly ( Fig. 2 ) and shorter two ones posteriorly ( Fig. 4 ), gland opening positioned in apical and axial position sensu Enghoff (1987). Penis subtrapezoidal, about 1.6 times longer than wide ( Fig. 3 ).

Gonopods slightly protruding. Anterior gonopod flattened, with parallel margins, apically strongly obliquely rounded, in posterior view apically excavated for accommodation of mesomeral process, distal margins of the excavation papillate ( Figs 6–7 ). Flagellum slender, of medium length, caudally covered with cuticular conical spikes ( Fig. 5 ). Opisthomere slender ( Fig. 8 ). Mesomeral process slightly arched forward, its apex covered with papillae. Margin of velum smooth, arcuate, with a deep notch near the mesomeral process. Additional membrane with a serrate edge. Solenomere spinose throughout, basally with blade (bb) ( Figs 8–9 ).

Etymology. Honours Genrikh Davidian, one of the collectors of this material. A noun in genitive.

Remarks. Nepalmatoiulus davidiani sp. nov. differs from N. angustus mainly by the smaller body length (about 18.0 mm) and larger midbody vertical diameter (about 1.4 mm) (vs. length—32.0–34.0 mm, midbody vertical diameter—about 2.5 mm in N. angustus ), by the coloration of the usual julid type of rings below ozopore level, (vs. from dark gray with a pale swoop to gray-dark brown in N. angustus ), by the strongly obliquely rounded apex of gonopod promere, by the male coxa 2 with one mesapical oral seta anteriorly (vs. male coxa 2 with two ones anteriorly in N. angustus ), by the distal podomere of the male legpair 1 with one seta laterally and minute seta tarsal remnant (vs. distal podomere of the male legpair 1 without seta laterally and tarsal remnant in N. angustus ), by the long (longer than claw) setiform accessory claw ventrally in claw of all legs (vs. short, (equal to claw length) setiform accessory claw ventrally in claw of all legs in N. angustus ).

Figures

FIGURES 1–7. Nepalmatoiulus davidiani sp. nov., male holotype (ZMUM). 1. Leg 1, anterior view. 2. Coxae 2, anterior view. 3. Penis, caudal view. 4. Coxa 2, posterior view. 5. Apex of flagellum. 6. Distal part of right promere. 7. Right promere, posterior view. Scales: 10 μm (Figs 5, 6), 20 μm (Figs 1, 2, 3, 4), 100 μm (Fig. 7).

FIGURES 8–9. Nepalmatoiulus davidiani sp. nov., male holotype (ZMUM). 8. Opisthomere, mesal view. 9. Solenomere, mesal view. Abbreviation: bb, basal blade. Scales: 10 μm (Fig. 9), 100 μm (Fig. 8).