Hyleoglomeris kabutus Susukida, Nguyen et Eguchi, 2025

Susukida, Mayu, Kuroda, Mai, Toda, Mioka, Oguri, Emiko, Nguyen, Anh D. & Eguchi, Katsuyuki, 2025, A new conspicuously colored species of the genus Hyleoglomeris Verhoeff 1910 (Diplopoda: Glomerida: Glomeridae), with research perspectives on the genus in Japan, Zootaxa 5717 (1), pp. 100-114 : 102-107

publication ID	https://doi.org/10.11646/zootaxa.5717.1.6
publication LSID	lsid:zoobank.org:pub:684F2884-5E58-494F-B1C9-ACE88EA95868
DOI	https://doi.org/10.5281/zenodo.17890100
persistent identifier	https://treatment.plazi.org/id/039B5242-2239-FFA4-FF2A-FF6CC902FC45
treatment provided by	Plazi
scientific name	Hyleoglomeris kabutus Susukida, Nguyen et Eguchi
status	sp. nov.

Treatment

Hyleoglomeris kabutus Susukida, Nguyen et Eguchi , sp. nov.

[Japanese name: kabuto-tamayasude: 兜球DZNJ bjŀsvVx÷]

( Figures 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype. male ( MT20230910-01 - 03 ), Tokyo, Setagaya-ku, Todoroki , 35.6026 oN, 139.6460 oE, 21m a.s.l., 10 September 2023, leg. M. Toda (deposited in MNHAH).

Paratypes. 1 male ( MT20230910-01 - 01 , deposited in MNHAH) , 1 male ( MT20230910-01 - 02 , deposited in IEBR-Myr) , 1 female ( MT20230910-01 - 04 , deposited in MNHAH) , 1 male, 5 females, 1 juvenile ( MT20230910- 01 , deposited in MNHAH) , 3 males, 2 females ( MT20230910-02 , deposited in IEBR-Myr), same data as for the holotype (deposited in MNHAH) . 1 male ( EG20230422-888 - 01 ) , 1 male ( EG20230422-888 - 02 ), Shizuoka Prefecture, Susono City, Senpuku , 35.1836 oN, 138.9039 oE, 147.9m a.s.l., 22 April 2023, leg. K. Eguchi (deposited in NSMT) . 1 male (EG20230422-889-01, deposited in NSMT) , 1 male (EG20230422-889-02, deposited in EGcoll), Shizuoka Prefecture, Susono City, Senpuku , 35.1833 oN, 138.9040 oE, 144.2m a.s.l., 22 April 2023, leg. K. Eguchi

Non-type specimens examined

1 male ( MK20211102-178 - 1 ) , 1 female ( MK20211102-178 - 2 ), Tokyo, Setagaya Ward, Nakamachi, Todoroki Valley , 35.6076 oN, 139.6464 oE, 32.5m a.s.l., 02 November 2022, leg. Mai Kuroda. 1 male ( EG20220821-621 - 01 ) , 1 male ( EG20220821-621 - 03 ) , 1 female ( EG20220821-621 - 04 ) , 1 male ( EG20220821-621 - 16 ), Shizuoka Prefecture, Izu-shi, Yugashima , 34.8566 oN, 138.9232 oE, 453m a.s.l., 21 August 2021, leg. K. Eguchi. 1 male ( EG20221102-645 - 01 ) , 1 male ( EG20221102-645 - 02 ) , 1 male ( EG20221102-645 - 03 ), Kanagawa Prefecture, Odawara City, Castle Street , 35.2526 oN, 139.1537 oE, 29.5m a.s.l., 02 November 2022, leg. K. Eguchi. 1 male (20230422G_Tube4-01), 1 male (20230422G_Tube4-02), Shizuoka Prefecture, Susono City, Central Park , 35.1833 oN, 138.9041 oE, 22 April 2023, leg. Joe Kutsukake.

Diagnosis. Body length 5.17–6.72 mm (male), 6.19–7.66 mm (female), width of thoracic shield 2.20–2.83 mm (male), 2.43–3.26 mm (female). Ommatidia 5+1. Thoracic shield largely blackish-brown; with anterior 1/4 and lateral and posterior margins ivory-yellow; with yellowish-marbled anterolateral spot ( Figs 1B View FIGURE 1 & 2C View FIGURE 2 ). Terga 3–11 blackish-brown; with ivory-yellow lateral and posterior margins; with yellowish-marbled anterolateral area ( Fig. 1 View FIGURE 1 A-B). Anterior 1/4 of tergum 3 also ivory-yellow. Thoracic shield with 5 distinct transverse striae fully crossing the dorsum, with 6 additional transverse striae in lateral part only ( Fig. 2C View FIGURE 2 ). Hyposchism not reaching posterior margin of thoracic shield ( Fig. 2B–C View FIGURE 2 ). Telopods ( Fig. 3C–D View FIGURE 3 ) with syncoxital lobe in anterior view roundly pentagon-shaped; syncoxital horn deeply bifurcate, with short outer and long inner branches; both prefemoral and femoral trichosteles present, well developed, finger-shaped; telopodal femora in anterior view with strongly convex lateral outline; telopodal tibial process well developed, claw-shaped, strongly curved dorsomesad.

Differential diagnostic remarks. Hyleoglomeris kabutus sp. nov. differs from all other known Hyleoglomeris species by having a unique deeply bifurcate syncoxital horns. The new species can also be distinguished morphologically from the other two Japanese species, H. insularum and H. sulcata (for which the male is unknown), by a thoracic shield with 5 fully crossing transverse striae (vs. 2 fully crossing transverse striae in the latter two species) ( Verhoeff, 1936, 1942). It is similar to Hyleoglomeris magy by having telopods with a swollen femur, but clearly differs from the species in colouration patterns (see H. kabutus sp. nov. diagnosis vs. H. magy : general colouration—light yellow with pairs of black spots; thoracic shield light yellow to white with a transverse black band in posterior part, anterior margin of band with 3 notches; terga 3–11 light yellow with transverse black bands, with blank areas in the middle and on lateral sides; pygidium light yellow with a pair of large black spots). It also differs from the species in the shape of syncoxital lobe (sub-pentagon vs medially concave trapeziform), and shape of syncoxital horns (bifurcate vs. single).

Description: body length 5.99 mm; maximum width of thoracic shield 2.51 mm.

Colouration: Frons reddish-brown, with pale yellow lower-median area. Labrum yellow. Collum blackishyellow, with a very large yellow-brown marbled median spot. Thoracic shield (= tergum 2) blackish-brown, with anterior 1/4 and lateral and posterior margins ivory-yellow, with marbled yellowish anterolateral spot. Terga 3–11 blackish-brown, with ivory-yellow lateral and posterior margins, with marbled yellowish anterolateral area; anterior 1/4 of tergum 3 also ivory-yellow. Pygidium (= anal shield) blackish-brown, with ivory-yellow lateral and posterior margin. Terga feebly micro-scabrous but shining.

Head: Ommatidia 5 + 1, lenses convex, black. Tömösváry organ transverse oval, with the long axis ca. 1.85 times as long as short axis (length:width = 0.37 mm: 0.20 mm). Antennomere 6 large, clavate, longer than antennomere 4 and 5 combined, ca. 2.6 times longer than wide. Length of antennomere 1 = 0.16 mm, 2 = 0.17 mm, 3 = 0.35 mm, 4 = 0.13 mm, 5 = 0.20 mm, 6 = 0.52 mm, 7 = 0.05 mm. Width of antennomere 6 = 0.19 mm. Antennal tip with four apical sensory cones.

Gnathochilarum: Stipe subtriangular, longer than wide (when excluding palps), with several seta along anterior margin. With inner palp and outer stipital palps very short and digitiform, with inner palp thicker than outer palp. Lamellae linguales fused but with a longitudinal groove along mesal line, with several seta apically. Mentum subtriangular, shorter than wide, with inverted U-shaped apical outline, indistinctly subdivided longitudinally along mesal line.

Tergites: Collum semicircular, with two transverse striae.Anterior marginal area of thoracic shield with 5 distinct transverse striae fully crossing the dorsum, with 6 additional transverse striae in lateral part only. Hyposchism broad, not reaching posterior margin of thoracic shield. Other terga with one or a few short striae running anterodorsad from the posterolateral corner of each tergum. Pygidium in posterodorsal view with broadly and distinctly concave posteromedian margin.

Legs: Leg 17 strongly reduced, 4-segmented ( Fig. 3A View FIGURE 3 ). Coxite ( c17) with a short and triangle distomesal tubercle ( dt17) bearing a long seta, with outer lobe ( ol) roundly and relatively lowly produced ventrad. Podomere 1 ( p17.1) short, ca. 1.4 times longer than wide, with a small distomesal knob bearing a long seta. Podomere 2 ( p17.2) as long as wide, with a short seta near the distomesal corner. Podomere 3 ( p17.3), extremely reduced, ca. 0.6 times longer than wide. Podomere 4 ( p17.4) ca. 3 times longer than wide, with 3 short setae at the tip.

Leg 18 moderately reduced, 4-segmented ( Fig. 3B View FIGURE 3 ). Syncoxial notch very broad, roughly V-shaped. Coxite with relatively elongate and triangular distomesal tubercle which protrudes almost ventrad and bears a long seta. Podomere 1 ( p18.1) ca. 1.4 times longer than wide, with a small distomesal knob bearing a seta. Podomere 2 ( p18.2) ca. 1.4 times longer than wide, with a seta near the distomesal corner. Podomere 3 ( p18.3) 0.7 times longer than wide, with a distomesal seta. Podomere 4 ( p18.4) ca. 3.6 times longer than wide, with a short and stout seta at the tip.

Telopods massive, and incrassate mesad ( Fig. 3C–D View FIGURE 3 ). Syncoxital lobe ( syl) roundly pentagon-shaped, not straight nor emarginate). Syncoxital horn ( syh) well-colored (yellowish) and sclerotized, hairless, almost as long as syncoxital lobe, tilting distinctly toward syncoxital lobe. Syncoxite deeply bifurcate: outer branch much shorter than inner branch, slightly curved, with blunt tip; inner branch slightly curved, with elongate and blunt tip. Prefemur ( pref) in anterior view with lateral outline almost straight. Prefemoral trichostele ( pret) long and slender, digitiform, almost straight, apically with a long seta. Femur ( fe) evenly swollen laterally. Femoral trichostele ( fet) digitiform, almost straight, slightly slenderer and much shorter than pret (ca. ½ length of pret), apically with a long seta. Femoral process ( fp) square-shaped, with inner corner triangular and forming blunt apex directing ventromesad. Tibia ( ti) in anterior view semi-trapezoidal, with lateral outline almost straight, with a short seta near the distomesal end; in posterior view with a short seta near distolateral end. Tibial process ( tp) well developed, claw-shaped, strongly curved dorsomesad; tip in posterior view hidden behind femoral process. Tarsus ( ta) massive, claw-shaped, with a very short conical seta near the tip.

Variations

Males. Body length 5.19–6.72 mm (n = 7); maximum width of thoracic shield 2.20–2.83 mm (n = 7). Syncoxital lobe of telopod is distinctly or sometimes roundly pentagon-shaped. Syncoxital horns obviously shorter than or sometimes equal to syncoxital lobe. Femoral process is either rectangular or triangular shaped ( Fig. 3 View FIGURE 3 ).

Females ( Figs 5–6 View FIGURE 5 View FIGURE 6 ). Body length 6.19–7.66 mm (n = 7); maximum width of thoracic shield 2.43–3.26 mm (n = 7). Thoracic shield with 5–6 distinct transverse striae fully crossing the dorsum and 6–7 additional transverse striae in lateral part only. Caudal edge of pygidium is not concaved medially. Leg 1 with a coxital tubercle bearing a seta; tarsus with 12 macrosetae on mesal side ( Fig. 6C View FIGURE 6 ). Leg 2 with a coxital tubercle bearing two setae; tarsus with 11 macrosetae on mesal side ( Fig. 6D View FIGURE 6 ).

Vulva in posterior view roughly heart-shaped, large, covering approximately 2/3 of coxa of leg 2 ( Fig. 6D View FIGURE 6 ). Operculum ( ov) thin dorsoventrally, depressed medially. Mesal valve ( mv) with rounded mesal outline, without a depression on the surface. Lateral valve ( lv) with rounded lateral outline, with an oblique depression. Two valves forming a narrow slit between them, and bearing several setae along the slit; mv smaller than lv.

DNA barcodes. (Supplementary Data 2). A total of 20 specimens were sequenced for the COI fragment. All sequences are accessioned at the National Center for Biotechnology Information (NCBI) GenBank with the following accession numbers ( Table 1). The uncorrected p-distance within the new species ranges from 0% to 5.3% (n=20). In contrast, the uncorrected p-distance between the new species and other Hyleoglomeris species obtained from GenBank ranges from 12.8% (compared to H. awaumi ( LC713407 View Materials - LC713420 View Materials ) from Japan) to 17.7% (compared to H. emarginata (PQ871002) from China).

Habitat and Ecology. The species was collected from the soil at the base of a dead tree in Todoroki Valley Park and from the humid leaf litter beside a concrete wall in a car park alongside a forest road in Yugashima.At both sites, dozens of individuals were found in a small area.

Etymology. A noun, “ kabutus ” refers to the helmet of a Japanese samurai, “ kabuto ”, which is similar in appearance to the syncoxital horns and syncoxital lobe of the species telopods.