Nepalmatoiulus kabaki, Mikhaljova, 2023

Mikhaljova, Elena V., 2023, A contribution to the millipede fauna of China: descriptions of four new species of the genus Nepalmatoiulus Mauriès, 1983 from high-altitude areas of Yunnan Province (Diplopoda, Julida, Julidae), Zootaxa 5357 (2), pp. 285-300 : 296-298

Nepalmatoiulus kabaki sp. nov.

Figs 37–48

Material examined. Holotype: male (dissected) ( ZMUM), China, Yunnan Province, Laojunshan watershed rivers to Shigu & Liming, 26°53´32´´ N, 99°39´43´´ E, H = 3795 m, 03.06. 2014, leg. I. Belousov, I. Kabak. Paratype: 1 female (dissected) ( ZMUM), same data as for holotype . Nontype: 1 male (dissected) ( ZMUM), same data as for holotype .

Diagnosis. Differs from congeners mainly by the mesomeral process with rounded apex (a in Figs 43, 45 ) and very long (length reaching the apex of mesomeral process) subapical outgrowth (d in Figs 43, 45 ), as well as by the arcuate curved margin of the velum without a notch near the mesomeral process. In certain degree similar to Nepalmatoiulus simultaneus Mikhaljova, 2023 but differs from it by specific characters (see Remarks below).

Description. Male. Length in alcohol 24.0–26.0 mm, midbody vertical diameter 1.8–2.0 mm, with 51(–1) rings, excluding telson. Coloration in alcohol from marbled brown-grey to dark grey with broad longitudinal lighter dorsal strip. Legs and antennae dark brown; ventral parts of legs lighter. Axial suture dark brown. Head dark brown with light brown anterior part. Eyes black. Gnathochilarium marbled brown with yellow distal part. Apical portion of the dark brown mandible stipital lobe with lighter border. Head smooth, 2+1 epicranial setae, 4 supralabral setae, not less than 24 labral setae and a several setae on forehead. Eye patches almost oval, composed of not less than 47 ommatidia. Antennae medium-sized, rather slender and clavate. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica. Mandibular stipites with ovale smooth lobes. Gnathochilarium: not less than 10 nonapical stipital setae; lamellae linguales each with not less than 5 setae arranged longitudinally.

Collum laterally with distinct lower striae at posterior margin not reaching to anterior margin, dorsally with distinct short striae at posterior margin. A transverse row of very sparse setae at hind edge of collum.

Body rings circular. Prozona smooth. Metazona with dense, regular, longitudinal striae reaching hind margin (16–20 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 metazonite slightly touching the suture in anterior body part, slightly set off from the suture in the second half of the body. Caudal dorsal projection of telson straight and long, covered with setae and carrying at tip a claw-shaped process curved dorsad. Preanal ring setose, anal valves densely setose; subanal scale densely setose along caudal edge.

Legs relatively short and slender. Very delicately serrate ventral pads present on postfemur and tibia, starting from legs 2 ( Fig. 39 ). Claw of all legs at base with a long (longer than claw) setiform accessory claw ventrally ( Fig. 38 ). Leg pair 1 forming a hook, the distal segment not touching basal segments (“Open hook” type in Enghoff 1987): coxa with one seta, postfemur with scaly-rugose ventral surface, tip practically not wrinkly, distal segment without seta and tarsal remnant ( Fig. 37 ). Coxa 2 with one mesapical oral seta (o), a gland opening positioned in central and axial position according to Enghoff (1987) ( Fig. 41 ). Penis relatively long, slender, slightly hourglassshaped, about 0.5 × longer than wide ( Fig. 40 ). Ventral margin of body segment VII with lobes similar to figure 32 in Enghoff (1987).

Gonopods protruding. Anterior gonopod with parallel margins, apically relatively obliquely rounded, distal margins of the apical excavation papillate (the papillary field is quite extensive), rudimentary telopodite without seta ( Fig. 42 ). Flagellum relatively long, slender, caudally covered with cuticular spikes in the distal part. Mesomeral process with rounded glabrous apex (a) and subapical, cone-shaped, very long (length reaching the apex of mesomeral process, as a result the mesomeral process proper looks forked), apically papillate outgrowth (d) ( Figs 43, 45, 48 ). Velum (v) merging with the apex of the mesomeral process. Velum margin smooth, arcuate, without a notch near the mesomeral process (see Discussion below). Margin of accessory membrane (m) serrate ( Figs 43, 44 ). Anterior surface of the mesomeral process with longitudinal subbasal deepening (n) ( Fig. 45 ). Slender long solenomere (sl) spinose nearly throughout, excluding laterocaudal surface of the basal half ( Figs 44, 46 ).

Female. Length in alcohol about 27.0 mm, midbody vertical diameter about 2.5 mm, with 49(–1) rings, excluding telson. Coloration in alcohol marbled gray-brown with broad longitudinal light brownish-pale dorsal strip. Vulva as in Fig. 47 .

Etymology. Honours Dr. I. I. Kabak, one of the collectors of this material. A noun in genitive.

Remarks. Nepalmatoiulus kabaki sp. nov. differs from N. simultaneus mainly by rounded apex (vs hookshaped in N. simultaneus ) and much longer subapical outgrowth of the mesomeral process, as well as arcuate curved margin of the velum (vs velum with a rather sharply sloped margin in N. simultaneous ).

The second male was not assigned to the type series for the following reasons. Both solenomeres of this male are shorter than those of the male holotype because they are broken off. This is evidenced by the uneven edges of their apex, as well as the different length of the right and left fragments of the solenomeres. In addition, the coloration of male nontype in alcohol has a gray tint in contrast to the clear coloration of the male holotype. Other main distinguishing characters as in the male holotype. However, the left coxa 1 (anterior view) of the male nontype has two setae, while the right one has one seta. I consider two setae as a random deviation from the norm. Also, the head of the male nontype has 1+1 epicranial setae while the one of the male holotype with 2+1 such setae. I also consider the 2+1 epicranial setae in the male holotype as abnormality.

Figures

FIGURES 37–41. Nepalmatoiulus kabaki sp. nov., male holotype (ZMUM). 37. Leg pair 1, anterior view. 38. Claw 2. 39. Mid-body leg. 40. Penis, posterior view. 41. Coxae 2, anterior view. Abbreviation: o, mesapical oral seta. Scales: 10 μm (Fig. 38), 20 μm (Figs 40–41) 100 μm (Figs 37, 39).

FIGURES 42–48. Nepalmatoiulus kabaki sp. nov., male holotype (Figs 42–46, 48) and female paratype (Fig. 47) (ZMUM). 42. Left promere, posterior view. 43. Opisthomere, mesal view. 44. Solenomere and accessory membrane, mesal view. 45. Opisthomere, lateral, slightly anterior, view. 46. Solenomere, lateral, slightly anterior, view. 47. Vulva, posterior view. 48. Apex of subapical outgrowth of mesomeral process. Abbreviations: a, apex; d, subapical outgrowth; m, accessory membrane; n, deepening; sl, solenomere; v, velum. Scales: 10 μm (Figs 46, 48), 20 μm (Fig. 44), 100 μm (Figs 42, 43, 45, 47).