Nepalmatoiulus karnaliensis, Mikhaljova, 2025

Mikhaljova, Elena V., 2025, The millipede genus Nepalmatoiulus Mauriès, 1983 (Diplopoda, Julidae) in Nepal, with descriptions of two new species, Zootaxa 5706 (3), pp. 426-438 : 427-432

Nepalmatoiulus karnaliensis new species

Figs 1–23

Material examined. Holotype: male ( ZMUM), Western Nepal, Karnali Province, Humla District, 12–13.5 km SE of Simikot, Ghatte , Yanchu Khola to Simikot , N 29˚54′23′′–29˚53′37′′, E 81˚55′7′′–81˚55′36′′, 2920–3490 m, pasture and disturbed mixed forest, 18.VI.2022, leg. D. Telnov; paratypes: 3 males, 2 females, 1 juvenile ( ZMUM), same data as for holotype; 2 males, 3 juveniles (among them 1 subadult male with 5 apodous body rings) ( ZMUM), Western Nepal, Karnali Province, Humla District , ca 12–13 km SE of Simikot, N 29˚54′23′′–29˚54′00′′, E 81˚55′7′′– 81˚55′11′′, 2990–3310 m, disturbed mixed forest, 17–18.VI.2022, leg. D. Telnov.

Diagnosis. Differs from congeners mainly by the apex of the solenomere densely spinose, with anteromesal flagellate spines, by the straight margin of velum, by a deep notch of the velar margin near the mesomeral process.

Description. Males. Length in alcohol 12.0–18.0 mm, midbody vertical diameter 0.9–1.2 mm, with 42(–4), 42(–4), 44(–3), 47(–2), 48(–2), 48(–1) rings. Coloration (in alcohol) marbled dark brown, colour pattern of entire rings of the usual julid type (description of the pattern of the julid type see Enghoff 1982). Eyes black, antennae dark brown. Legs light marbled brown.

Head smooth, 2 epicranial setae, 4 supralabral setae; at least 16 labral setae. Eye patch subtriangular; one of the paratypes had at least 30 ommatidia. Antennae medium-sized, rather slender and clavate. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica ( sb) ( Figs 1, 2 ; in the figs almost all sb are broken off). Mandibular stipites with large, evenly rounded, slightly swollen lobes. Gnathochilarium with small group of nonapical stipital setae; lamellae linguales each with 5 setae arranged longitudinally. Collum with striae at posterior margin. A transverse row of relatively long or short setae (short setae—in males from 2990–3310 m a.s.l.) at hind edge of collum mainly dorsally.

Body rings circular. Metazona with dense, regular, longitudinal striae reaching hind margin (12–13 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 thin and sparse setae (sparse setae in males from 2990– 3310 m a.s.l.) at hind edge of metazonites, setae gradually growing denser toward telson. Ozopores very small, lying behind suture dividing pro- and metazona touching the suture. 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 covered with setae.

Legs short and very slender. Very delicately serrate ventral pads ( vp) present on postfemur and tibia, starting from legs 2 ( Figs 3 , 7–11 , vp is not indicated in Figs 7–10 ). The claws have a traditional hooked shape with a ribbon-shaped accessory claw at the base ( Fig. 17 ); accessory claw probably longer than claw. However, only two claws of this shape were found among the male paratypes. There are a lot of legs in all paratypes with claws in the form of a cylinder with a slightly expanded base and a subbasal projection ( Figs 9, 11–12, 14–15 ) or legs without claws at all ( Figs 7–8, 10 ). This variation in the claws is the same in the holotype. This is most likely the result of any damage (see remarks below). 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 indistinct scaly-rugose ventral surface, coxa with one seta, distal podomere without seta ( Fig. 5 ). Coxa 2 with one long mesapical oral seta anteriorly, gland opening positioned in central and axial position sensu Enghoff (1987) ( Figs 3, 6 ). Penis subrectangular, about 1.9 times longer than wide ( Fig. 4 ).

Gonopods slightly protruding from ring 7. Promere flattened, with parallel margins, apically strongly obliquely rounded, in posterior view apically excavated for accommodation of mesomeral process, distal margins of the excavation sparingly papillate (the papillary field is not very extensive), rudimentary telopodite ( t) without seta ( Fig. 20 ). Flagellum ( f) slender, of medium length; its basal part covered with cuticular conical spikes on the caudal side; its distal part completely covered with cuticular conical spikes ( Fig. 18 ). Mesomeral process of the opisthomere moderately thick, with rounded, strongly papillate apex ( a) ( Figs 18–19 ). Velum ( v) with straight margin, tiny denticles posteriorly and a deep notch ( dn) near the mesomeral process ( Figs 18–19 ). Anterior surface of the mesomeral process with longitudinal concavity ( d) ( Fig. 19 ). Additional membrane ( m) with a smooth edge anteriorly ( Fig. 18 ). Solenomere ( sl) moderately stout, apically concave, caudally densely spinose, basally with an obliquely ascending spinose ridge ( r); apex of the solenomere densely spinose, with anteromesal long flagellate spines ( fs) ( Figs 18–19, 21–22 , fs is not indicated in Figs 18–19 ).

Females. Length in alcohol 18.0–20.0 mm, midbody vertical diameter 1.4–1.5 mm, with 46(–2), 47(–1) rings. The claws with a basal setiform accessory claw ventrally ( Figs 13, 16 ) (see remarks below). Vulva: operculum somewhat higher than bursa, apically with excavation. Posterior median plate with two rows of setae (at least 6 setae in each), apical setae longest ( Fig. 23 ).

Juveniles. Length in alcohol 11.0–12.0 mm, midbody vertical diameter 0.9 mm, with 40(–3), 40(–3), 42(–3), 42(–5) rings. Coloration as in males.

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

Remarks. The large number of non-standard claws in all paratypes and the holotype is worthy of more consideration. The shape of the claws of N. karnaliensis sp. nov. was studied in the holotype and all paratypes ( 5 males, 2 females, and 4 juveniles) from two biotopes at different altitudes, one at 2920–3490 m and the other at an altitude of 2990–3310 m.

In males, traditional hooked claws are more common on pregonopodal legs ( Fig. 17 ). In addition, males have many legs with claws in the shape of a cylinder with a slightly expanded base and with or without a subbasal projection ( Figs 9, 11, 15 ). There are also many legs with no claws at all ( Figs 7–8, 10 ). These claws are likely either broken off and torn off or damaged in some other way. All legs, both with and without claws, are equipped with ventral pads.

Females have quite a lot of legs with traditional hooked claws, which are equipped with either broken off accessory claws ( Fig. 16 ) or are devoid of them (the basal projection is smoothed) ( Fig. 13 ). Females also have legs without claws, which are probably torn off.

In juveniles, most of the legs are either without claws or with claws in the form of a cylinder with or without a subbasal projection ( Figs 12, 14 ). Only one juvenile with 3 legless rings before telson (from a biotope at an altitude of 2990–3310 m) was found to have formed hooked claws on the 3rd and 4th pairs of legs; however, these claws were without a ventral subbasal accessory claw, but with a projection in its place (the ventral subbasal accessory claws were probably broken off). Ventral tarsal pads are either present or absent, regardless of the presence or absence of a claw. The legs of juvenile males have ventral tarsal pads (for example a subadult male from a biotope at an altitude of 2990–3310 m).

The described condition of the claws was noted in paratypes from two different biotopes at different altitudes. However, since the material was collected by the same collector, it is assumed that it is caused by the damage of the claws during collection, fixation or drying of the material.

Figures

FIGURE 23. Nepalmatoiulus karnaliensis sp. nov., female paratype (ZMUM). Vulva, posterior view. Scale: 20 μm.

FIGURES 1–6. Nepalmatoiulus karnaliensis sp. nov., male paratype (ZMUM). 1. Distal part of antenna. 2. Apex of antenna. 3. Leg pair 2, anterior view. 4. Penis, posterior view. 5. Leg pair 1, anterior view. 6. Coxae 2, anterior view. Abbreviations: sb, sensilla basiconica; vp, ventral pads. Scales: 10 μm (Figs 2, 4), 20 μm (Figs 1, 5–6), 100 μm (Fig. 3).

FIGURES 7–17. Nepalmatoiulus karnaliensis sp. nov., male, female and juvenile paratypes (ZMUM). 7. Male paratype from 2920–3490 m a.s.l., mid-body leg. 8, 9, 10. Male, back-body leg. 11. Male, apex of leg 5. 12. Subadult male, apex of leg 1. 13. Female, apex of leg 4. 14. Subadult male, apex of leg 2. 15. Male, apex of leg 2. 16. Female, claw of hind leg. 17. Male, claw of leg 2. Scales: 2 μm (Figs 15–17), 10 μm (Figs 11, 13–14), 20 μm (Figs 7–10, 12), 100 μm (Fig. 3).

FIGURES 18–22. Nepalmatoiulus karnaliensis sp. nov., male paratipe (ZMUM). 18. Gonopods, mesal view. 19. Opisthomere, lateralview.20.Promere,posteriorview.21.Apexofsolenomere,lateralview.22.Apexofsolenomere,mesalview.Abbreviations: a, apex of mesomeral process; d, concavity; dn, notch; f, flagellum, fs, flagellate spines; m, additional membrane; r, ridge; sl, solenomere; t, rudimentary telopodite; v, velum. Scales: 10 μm (Figs 21–22), 20 μm (Figs 18–20).