Sphaerobelum konkakinhense Semenyuk, Golovatch and Wesener, 2018

Semenyuk, Irina, Golovatch, Sergei I. & Wesener, Thomas, 2018, Four new species of giant pill-millipedes from Vietnam (Sphaerotheriida, Zephroniidae), Zootaxa 4459 (3), pp. 535-550 : 540-543

Sphaerobelum konkakinhense Semenyuk, Golovatch and Wesener , sp. nov.

Figs 1B , 4B , 5 , 6

Material examined: Type specimens. Holotype male ( ZMUM), Vietnam, Gia Lai Province, Kon Ka Kinh National Park , near summit (N 14°12' E 108°18', 1400–1500 m. a.s.l.), mixed tropical cloud forest, slopes, litter and under logs, V.2017, leg. I.I. Semenyuk. Paratypes: 1 male, 1 female , ZFMK MYR 6611 , 6612 , same data as holotype ; 1 female ( ZMUM), same data as holotype.

Diagnosis. Medium-sized, up to 30 mm long, chestnut Sphaerobelum with a setose surface and basally dark, apically light brown appendages. Modified femur with a dentate mesal margin, modified prefemur with a lateral process ( Fig. 5D ), female operculum at apical margin depressed centrally ( Fig. 5H ), all these characters shared only with S. bicorne . Sphaerobelum konkakinhense sp. nov. differs from S. bicorne in the presence of the anterior telopod with four telopoditomeres (vs. 3 in S. bicorne ) and a much less strongly invaginated female operculum. Process of anterior telopod visible also laterally in anterior view, with a rectangular apex ( Fig. 5B ). Immovable finger of posterior telopod swollen apically, extending mesally and laterally ( Figs 5F, G ).

Description. Measurements: Holotype male. Body length ca 30 mm, width of thoracic shield = 13.4 mm, of tergite 8 = 14.0 mm (= broadest), height of thoracic shield = 8 mm (= highest). Female (largest): length ca 28.6 mm, width of thoracic shield = 13.4 mm, of tergite 9 = 14.1 mm (= broadest), height of thoracic shield = 7.8 mm, of tergite 9 = 8.4 mm (= highest). Coloration: in live specimens, head and collum dark brown. Tergites paler dark brown with grey hue ( Fig. 1B ). Ventral surface of body clothed with short, yellowish, fur-like setae. Legs and antennae much paler, greyish, with yellowish setae. In preserved specimens, head dark brown. Antennae and legs dark brown, legs distal to postfemora, as well as antennomere 6 contrasting light brown. Head: wide and short. Eyes with>60 ocelli. Aberrant ocellus located inside antennal groove. Antennae short, with rounded joints, extending posteriorly to leg-pair 2. Antennomeres 1 and 2 with few sclerotized scales ( Fig. 6A ). Sizes of antennomeres 1>2=3=4=5<<6 ( Fig. 6A ). Antennomere 6 densely pubescent, with a single row of sensilla basiconica partly surrounding apical disc. Shape of antennae sexually dimorphic, cylindrical in female, axe-shaped in male ( Fig. 5E ). Male apical disc with 75/78 apical sensory cones ( Fig. 6B ), that of female with 31/33 apical cones. Organ of Tömösváry located inside antennal groove. Gnathochilarium: structure typical of the order. Stipites and paramentum bearing several long setae. Mandibles (not examined). Stigmatic plates: first stigmatic plate triangular, apex broadly rounded, curved towards coxa 1. Laterotergites: first laterotergite tip slightly extended, sharply edged. Collum: covered with sparse long setae. Thoracic shield: surface as in tergites (below). Shallow grooves filled with numerous long setae, sloping towards groove with 6 keels. Tergites: surface covered with small pits, many carrying a tiny seta. Tips of paratergites of midbody tergites projecting posteriorly. Endotergum: inner section lacking any large spines or setae. Middle area with a single row of large, sparse, elliptical, cuticular impressions. Apically two rows of long marginal bristles protruding regularly beyond tergal margin by more than a quarter of their length ( Fig. 4B ). Bristles not smooth, but with numerous small spinicles ( Fig. 4B ). Anal shield: large and well-rounded. Surface similar to that of tergites. Underside carrying a single, black, locking carina of medium length, located close to last laterotergite. Legs: leg 1 with 2, leg 2 with 4 or 5, leg 3 with 5 ventral spines. First two leg-pairs without an apical spine. Leg-pairs 4–21 with 6–10 ventral spines and an apical spine. In leg-pair 9X, femur 1.5X, tarsus 4.5X longer than wide ( Fig. 5D ). All podomeres setose. Coxa with a large and well-rounded process (= coxal lobe). Prefemur at apical margin with a projection laterally and mesally. Lateral projection triangular with sharp edge, juxtaposed to coxal lobe.

Female sexual characters: vulva large, covering 2/3 of coxa, extending mesally to half of prefemur length ( Fig. 5H ). Operculum rounded, invaginated medially, projecting in a lateral and a strongly projecting mesal lobe. Mesal lobe more than twice as high as lateral lobe, slender, 2.4X longer than wide. Subanal plate: large, relatively low, with an invagination at midpoint of apical margin, creating two wide and well-rounded tips.

Male sexual characters: gonopore covered with a single, undivided, triangular, sclerotized plate. Anterior telopods ( Figs 5A–C ): consisting of syncoxite plus 4 telopoditomeres. First telopoditomere rectangular, slightly longer than wide. Telopoditomere 2 large, as long as telopoditomeres 3 and 4 combined. Process of telopoditomere 2 located posteriorly, but partly visible laterally in anterior view. Process slender, projecting as far as base of telopoditomere 4, apical part rectangular, slightly broader than basal part. Telopoditomere 3 as long as 4th, longer than wide, on posterior side with a single short spine apically. Telopoditomere 4 well-rounded, longer than wide, slightly tapering apically. Posterior surface with 4 black spines, apical-most one being the largest. All podomeres covered with sparse long setae. Posterior telopods ( Figs 5F, G ): first telopoditomere elongated, 1.4X as long as wide. Immovable finger (process of telopoditomere 2) shorter than movable finger, consisting of telopoditomeres 3 and 4. Immovable finger with apex characteristically swollen distally, extending mesally and laterally, but only faintly so, apex therefore only slightly broader than base. Telopoditomere 3 elongated, towards immovable finger in apical half with a large extension carrying at least three large spines. Telopoditomere 4 slender, only half as broad as telopoditomere 3, 3.6X longer than wide, slightly tapering apically, straight. At inner margin with four spines placed between midpoint and apex. Entire telopodite on anterior side covered with long setae, except for immovable finger and telopoditomere 4. In posterior view, telopoditomeres 3 and 4 setose only at lateral margins.

Distribution and Ecology. This species is restricted to a very small area at the peak of a mountain, at 1500 m. altitude. The mountain-top is only slightly sloped (less than 30° inclination) and supports a unique cloud forest which is absent from lower elevations. Leaf litter is very thick (about 10 cm) and consists of several layers, while the forest floor is covered with Selaginella spp. and a dense understory. Millipedes are only found in May, during the rainy season. The population density is very low and the animals mainly occur in leaf litter, a few are also found under logs. The millipedes usually build chambers within leaf litter and persist there, likely consuming leaf litter. Numerous abandoned chambers were found full of feces. The millipedes are very timid and, after being disturbed, unroll only after about 5 minutes later. Any additional disturbance causes them to roll up for a longer time.

Name. Adjective, to emphasize Kon Ka Kinh National Park, its type locality ( Fig. 1 ).

Figures

FIGURE 1. Distribution map with pictures of live specimens. A. Sphaerobelum cattiense sp. nov.; B. Sphaerobelum konkakinhense sp. nov.; C. Zephronia konkakinhensis sp. nov.; D. Zephronia montis sp. nov.

FIGURE 4. Endoterga of midbody rings. A. Sphaerobelum cattiense sp. nov. Male paratype (ZFMK MYR6516); B. Sphaerobelum konkakinhense sp. nov., male holotype (ZMUM). Scale bars: 100 µm.

FIGURE 5. Sphaerobelum konkakinhense sp. nov. A–F, H = male holotype (ZMUM), G = female paratype (ZFMK MYR6612). A: right anterior telopod, posterior view; B and C: right anterior telopod, anterior and lateral views, respectively; right anterior telopod; D. left leg 9, posterior view; E. right male antenna; F. posterior telopod, posterior view; G. posterior telopod, anterior view; H: vulva. Not to scale.

FIGURE 6. Sphaerobelum konkakinhense sp. nov., male holotype (ZMUM), right antenna. A. lateral view; B. apical view of disc. Abbreviations: sc = sclerotized scales; sb = sensilla basiconica. Scale bars: A = 1000 µm; B = 100 µm.