Julus bengeli, Nefediev & Nefedieva, 2025

Julus bengeli sp. nov.

Figs 1–2 View FIGURES 1–3 , 4–38 View FIGURES 4–10 View FIGURES 11–18 View FIGURES 19–26 View FIGURES 27–30 View FIGURES 31–38 , Map.

MAP. Distributions of Julus species in the Russian Altais (red dotted line): azarovae (green circle), bengeli sp. nov. (red circle), brachydactylus (blue triangle), ghilarovi (yellow circle), kazakhus (purple circle).

Material examined. Holotype male ( ZMUM Rd 5540, intact), Russia, southwestern Siberia, Republic of Altai, Ongudai District, environs of Belyi Bom (=Ak Boom), near monument to Kolka Snegiriov, old road of Chuya Tract, 50.353344° N, 87.056930° E, 1005 m a.s.l., Caragana thicket with Artemisia herbal vegetation on W slope, under stones, 30 June 2016, collected by P. S. Nefediev, Yu. S. Nefedieva, A. P. Nefediev, A. P. Nefedieva & J. Bichl.

Paratypes: 1 male (in 3 pieces: head with dissected gnathochilarium and antennal fragment; segments 2–6 with dissected leg pairs 1 and 2; the rest of the trunk with dissected gonopods), 1 male (in 5 pieces: head with dissected antenna, eye patch, mandibular gnathal lobes, gnathochilarium, and collum; segments 2–7 with dissected pregonopodal legs and gonopods; several trunk parts, including telson; two midbody pieces 10 rings each were used for DNA barcoding), 1 female (in 3 pieces: head with dissected gnathochilarium + collum + segment 2 with leg pair 1; segments 3–4 with dissected vulvae and leg pair 2; rest of the trunk), 4 subadult males, 7 subadult females, 4 juveniles (all ASU.NPS.D-017), 1 female ( ZMUM Rd 5541, intact, with everted vulvae), same data as for holotype .

Diagnosis. Differs from all congeners by the presence in males of a distinct projection located parabasally on the gnathochilarial stipes, and apically carrying a circular bundle of 15–17 elongated papillae/trichomes ( vs the absence of such structure in all other species of the genus). Otherwise, the new species is very close to J. ghilarovi Gulička, 1963 , but differs from this species by the combination of the following characters: a conical apical outgrowth of the telopodite 1 of leg pair 1, and a pair of large anterior coxal outgrowths of leg pair 2 thickened in the central portion.

Name. To honour Bengel, the authors’ favorite dachshund, who accompanied us on a trip to the Altais during which the material was collected, and tragically died this year. Noun in genitive case.

Description. Male. Length 28 mm, vertical diameter 1.4 mm, with 58(–2) segments, excluding telson.Coloration in alcohol dark brown with pale, discolored prozonites ( Fig. 1 View FIGURES 1–3 ). Antennae dark brown, eye patches black. Legs dark brown with light brown or brown coxae and prefemora. Eye patches subtriangular, each composed of ca 40 ommatidia. Epicranial setae 1+1, supralabral setae 3+3, labral ones 10+10 ( Fig. 4 View FIGURES 4–10 ). Mandibular stipites unmodified. Antennae medium-sized, rather slender and clavate ( Fig. 5 View FIGURES 4–10 ), in situ reaching back to body segment 5. Antennomeres 5 and 6 ( a5 & a6, respectively) with distodorsal corolla of 13–15 sensory bacilliform sensilla ( Fig. 6 View FIGURES 4–10 ). Antennomere 7 ( a7) with distodorsal corolla of minute sensory bacilliform sensilla; terminal disc with four sensory cones. Length ratios of antennomeres 1–7 as 2.3:7.7:5.8:5.6:7.2:3.4:1, width ratios as 1.2:1.3:1.2:1.2:1.7:1.4:1, respectively. Gnathochilarium different in males and females; in males ( Fig. 7 View FIGURES 4–10 ), gnathochilarial stipes ( st) parabasally with a distinct projection apically carrying a circular bundle of 15–17 elongated papillae/trichomes ( Figs 9, 10 View FIGURES 4–10 ), and a longitudinal group of ca 20 short setae in paramedian portion of stipes; each lamella lingualis ( ll) with 7–8 setae (2 long distal setae and 5–6 short proximal ones) ( Fig. 7 View FIGURES 4–10 ). Mandibular gnathal lobe as follows: external tooth ( et) with large apical cusp; internal tooth ( it) comb-shaped, with five apically rounded cusps; 4 rows of pectinate lamellae ( pl) with simple, bacilliform teeth; intermediate area ( ia) with serrate papillae; molar plate ( mp) with a few transverse ridges, its anterior fringe ( af) with serrate and nonserrate spines ( Figs 11, 12 View FIGURES 11–18 ).

Body subcylindrical, slender, slightly compressed laterally. Somites 6 and 7 somewhat stouter than others. Ventral edges of pleurotergum 7 outcurved, forming a gonopodal aperture. Ozopores ( o) small, lying considerably behind the suture at almost one third of the length of metazona ( mz) ( Fig. 14 View FIGURES 11–18 ). Metazona with striations reaching the hind margin; 10 striae on metazonite surface between dorsal midline and ozopore. Caudal margins of metazona with minute, relatively sparse setae, gradually growing a little bit longer on pregonopodal rings ( Fig. 14 View FIGURES 11–18 ). Telson with sparse long setae dorsally; epiproct ( e) somewhat flattened dorsoventrally, triangular in ventral view, with a small, apical, claw-shaped projection directed caudad. Anal valves (paraprocts, p) convex, densely setose along their edges; subanal scale (hypoproct, h) subtriangular, with a submarginal row of several setae ( Fig. 13 View FIGURES 11–18 ).

Walking legs relatively short and slender. Claws at base of all walking legs with a long accessory claw ventrally (marked with arrows in Fig. 16 View FIGURES 11–18 ), without additional small claws dorsally. Pregonopodal leg pairs 3–7 ( Figs 15, 17 View FIGURES 11–18 ) somewhat wider than postgonopodal ones; gradually becoming slenderer from leg pair 3 toward leg pair 7; coxae 3–7 with small protrusion apically; prefemur 3 ( pr3) densely setose with strong, elongated setae ventrally; prefemora 4–5 ( pr4 & pr5, respectively) with a small ventral protrusion carrying short, robust setae. Leg pair 1 ( Figs 18–21 View FIGURES 11–18 View FIGURES 19–26 ) small, subtriangular; coxite ( cx1) with pointed apex curved anteriad; suture between cx1 and a roundish 1-segmented telopodite remnant ( te) well expressed, bearing a pair of strong setae near the suture; te with strong setae on perimeter carrying a conical apical outgrowth ( cao). Leg pair 2 ( Figs 22–26 View FIGURES 19–26 ) with three pairs of coxal outgrowths: (1) a pair of large anterior coxal outgrowths ( lao) (apparently, homologue to a main process ( mp) in Evsyukov et al. 2018) curved anteriad, thickened in the central portion, bearing caudal process curved toward dorsum; (2) a pair of smaller, slender anterolateral coxal outgrowths ( alo) (apparently, homologue to a second anterior coxal outgrowth ( ao2) in Mikhaljova 2009, as well as an anterolateral process ( alp) in Evsyukov et al. 2018) that are pointed and bi- or trifurcated apically along their caudal edges, with a small cavity in the centre; (3) a pair of subroundish posterior coxal outgrowths ( po) (apparently, homologue to a posterior process ( pp) in Evsyukov et al. 2018) with a seta subapically. Prefemur 2 ( pr2) with a group of elongated setae mesally. Penes ( p) subconical ( Fig. 25 View FIGURES 19–26 ).

All three parts of each gonopod highly compact in the longitudinal direction ( Figs 27–30 View FIGURES 27–30 ). Promere ( pm) higher than opisthomere, its flagellum ( fl) well-developed, ribbon-shaped, with a somewhat broadening end, armored with tiny spines ( Fig. 34 View FIGURES 31–38 ). Promere with pointed apex, lateral prominence and caudal longitudinal crest ( lc) on posterior surface, without telopodite remnant; its anterior surface perforated by numerous tiny pores, mostly along outer edge ( Figs 27–31 View FIGURES 27–30 View FIGURES 31–38 ); some pores on posterior surface of promere apex sealed with secretions ( Fig. 32 View FIGURES 31–38 ). Mesomere ( m) conical, pointed at apex, slightly bent laterally ( Figs 27–28 View FIGURES 27–30 ). Opisthomere ( om) with setiform mesal outgrowth at base (marked with an arrow in Fig. 30 View FIGURES 27–30 ) and a flat, broad lateral process ( lp), strongly pointed apically ( Fig. 33 View FIGURES 31–38 ) and somewhat bent caudo-laterad; notch between solenomere ( sm) and lateral process as deep as near 1/3 opisthomere height ( Fig. 30 View FIGURES 27–30 ).

Female. Length 32 mm, vertical diameter 1.5 mm, with 57(–2) segments, excluding telson ( Fig 2 View FIGURES 1–3 ). Unlike males, gnathochilarial stipes ( st) of females devoid of a distinct projection with a circular bundle of 15–17 elongated papillae/trichomes basally, covered instead with 5 short setae from paramedian to parabasal portion of stipes arranged in a row; each lamella lingualis ( ll) with 4 setae arranged nearly longitudinally ( Fig. 8 View FIGURES 4–10 ). Each coxa of leg pair 2 with small subconical process directed forward (marked with an arrow in Fig. 35 View FIGURES 31–38 ).

Vulvae oblong, with strong setae ( Figs 37, 38 View FIGURES 31–38 ). Operculum ( op) higher than bursa ( bu); its apex with a subtriangular incision and at least 7 setae in each of two longitudinal rows, apical setae longest. Apical part of bursa with a pair of hyaline lobes. Lateral and mesal bursal sclerites together with 8 setae. Posterior median sclerite of bursa with 17 setae arranged in two rows, apical setae longest.

Subadult males. Length 16–26.9 mm, vertical diameter 1.0– 1.3 mm, with 49(–4), 50(–5), 55(–3), excluding telson. Leg pair 1 normal. Large anterior coxal outgrowths of leg pair 2 without additional processes caudally, a pair of posterior outgrowths undeveloped, gonopodal somite 7 normal, without gonopodal aperture, gonopods underdeveloped, hidden in segment ( Fig. 36 View FIGURES 31–38 ); body coloration as in adult males.

Subadult females. Length 18–24.1 mm, vertical diameter 1.1–1.3 mm, with 51(–3), 51(–5), 51(–6), 53(–3), 54(–3), 56(–3), excluding telson. Each coxa of leg pair 2 with a very small, clearly distinguishable subconical process directed forward.

Juveniles. Length 12–15.8 mm, vertical diameter 0.7–1.1 mm, with 37(–6), 40(–5), 40(–4), 45(–6), excluding telson.

Distribution. The new species is known only from the type locality: environs of Belyi Bom, Ongudai District, Republic of Altai, southwestern Siberia, Russia (Map).

Remarks. This species shows a stably high number of body segments in adults within the genus: 58 body rings in males and 57 in females excluding the telson. Only one species, Julus kubanus Verhoeff, 1921 , slightly surpasses the new species in the number of body rings (53–59 rings) vs 40–54 rings in other Julus spp. The new species dwells in bush and herbal habitat on an open western slope at about 1000 m a.s.l. ( Fig. 3 View FIGURES 1–3 ). Endemic to the Russian Altais.