Propodobolus sp.

Golovatch, S. I., Mauriès, J. P. & Akkari, N., 2021, On the collections of Indo-Australian Spirobolida (Diplopoda) kept in the Zoological Museum of the Moscow State University, Russia. 3. Some Rhinocricidae, Arthropoda Selecta 30 (1), pp. 3-27 : 4-6

Propodobolus sp.

Figs 1–9 .

MATERIAL. 2 ♂♂, 2 ♀♀ ( ZMUM), Indonesia, West Papua Province, Onin Peninsula , 5–7 km N of Fak-Fak, S2°53′, E132°18′, 300–400 m a.s.l., primary lowland tropical rainforest on limestone, 25.IX.2010, D. Telnov leg.

DESCRIPTION. Body ca. 170–185 mm long, width or height of midbody segments 14–15 mm (♂, ♀), with 54p+1ap+T (♀) or 56p+T (♂, ♀) segments. Colouration uniformly blackish to black-brown, antennae, legs, gonopods and telson dark red-brown, clypeus usually red ( Figs 1–9 ). Mesozonae often mottled with small light spots, apparently these being sigilla translucent from beneath.

Body cylindrical, postcollum constriction very faint ( Fig. 2 ). Head as usual, bare, with three small, but evident, central teeth at fore margin of, and a short, axial and distinct suture on, labrum, followed by a superficial, fine, axial, epicranial line, with ca. 7–8+7–8 labral and 2+2 supralabral setae. Eye patches suboval, large and blackish ( Fig. 1 ), each composed of ca. 23–25 flat ommatidia arranged in 5–6 vertical rows (e.g., ca. 5+5+5+4+3+2); interantennal isthmus ca. 2.5x diameter of eye patch ( Fig. 2 ). Antennae short and clavate, curved anteroventrad, in situ stretchable laterally behind until caudal margin of collum; in length, antennomere 2> 3> 4=5=6> 1> 7; antenomeres 5–7 clothed with particularly dense, but mostly short setae; 8 th with four small apical cones ( Figs 1, 2 ). Tegument bare, almost smooth, very finely leathery, mostly shining ( Figs 1–5 ). Collum broadly rounded and clearly bordered only anteriorly, sulcus being rather short; caudolateral surface very delicately, densely, longitudinally and irregularly striolate ( Fig. 1 ). Segment/ring 2 with a conspicuously flattened and subvertically striolate anteroventral part to subtend collum. Midbody segments/rings devoid of evident sutures between zonae, very poorly constricted and sometimes even slightly rugulose only between meso- and metazonae; dorsum bare until ring 7 or 8, following metazonae and, later, mesozonae sparsely, irregularly, mostly finely and longitudinally striate/striolate dorsally, striations often being rather vague and abbreviated both caudally and anteriorly, mostly being deeper on metazonae; mesozonae remaining smooth from about ozopore level down to a particularly densely, obliquely and irregularly striolate ventrolateral third, while metazonae striate across entire circumference, but increasingly clearly, more densely and regularly so ventrolaterally; prozonae particularly densely, confusedly and vertically striolate ( Figs 1–5 ). Scobinae absent. Ozopores small and round disks lying at fore margin of metazonae on all leg-bearing segments starting with segment 6 ( Figs 1, 3, 5 ). Telson ( Fig. 5 ) as usual, epiproct flat, small, digitiform, clearly concave dorsally at base, rounded caudally; paraprocts very strongly and regularly convex, smooth, clearly bordered into prominent caudal lips with a conspicuous gutter between both valves; hypoproct nearly semi-circular, transverse, rounded caudally. Only ♂ segment 7 clearly swollen ventrally, a complete ring due to a strong ventral bridge in caudal half ( Figs 1, 2 ). No visible sigilla on internal surface of meso- and metazonae.

Legs short and slender, ca. 2/3 as long as midbody height, each usually with a spine above and below claw, ventral spine being more clearly removed from claw; only ♂ legs 1 and 2 somewhat shorter and devoid of ventral sole pads on tarsi, while most following tarsi until those in ♂ caudal body third with evident sole pads; ♂ coxae 3–5 clearly expanded ventrally, rounded tubercles being more evident on coxae 3, but lower on coxae 5 ( Fig. 2 ).

Gonopods strongly sclerotized ( Figs 6–9 ). Anterior gonopods with an unusually prominent, high and semi-circular sternum (s) devoid of a median process, s being slightly higher than telopodites (t); the latter slender, each with a bulbous apical swelling (sw) on caudal face, only slightly longer than a stout coxa (cx) with its prominent, mesal, subtriangular process/lobe (lo); both lobes almost meeting at midline. Posterior gonopods (pg) connected with a simple, membranous, ribbon-shaped sternum, each gonopod consisting of a short subcylindrical coxa (cx2) and a slender, longer, bipartite telopodite (t2); apicolateral branch (lb) the largest, clearly curved, apically expanded into a small and obliquely truncate blade with a short, curved, apicolateral, flagelloid spike; mesal branch (= solenomere, sl) much shorter, flagelliform, originating just at base of t2.

REMARKS. This species readily resembles the particularly similar Propodobolus adipatus (Karsch, 1881) and P. beauforti ( Attems, 1914) , both nicely described and illustrated by Attems [1915] from Waigeo Island (formerly Waigeu), Raja Ampat Islands, Indonesia, and both showing rather irregular and vague striations on the metazonae, as well as hypertrophied and apically rounded sterna of the anterior gonopods. However, our species differs by the slightly higher sternum and apically non-pilose telopodites of the anterior gonopods. Moreover, P. adipatus and P. beauforti are so close both morphologically and geographically that they may well prove to represent different adult ♂ developmental stadia of a single species. Gradual changes in gonopodal struncture have long been shown in the hemianamorphosis of Rhinocricidae [ Mauriès, 1980; Enghoff et al., 1993; Bond et al., 2003]. So we are inclined instead to leave our sample unidentified closer.

In Propodobolus quintiporus ( Attems, 1897) (the type species of the genus), P. compactilis ( Attems, 1897) , P. fulvescens ( Carl, 1918) , P. pachyskeles ( Attems, 1897) , and P. xanthopygus ( Attems, 1897) , all from the Moluccas, Indonesia [ Attems, 1897; Carl, 1918], the anterior gonopod sternum is somewhat lower, sometimes bilobed apically, and the telopodites are clearly drawn apart either side of the midline.

The western, currently Indonesian part of New Guinea alone is also known to support a bunch of dubious rhinicrocids formally belonging to several genera, all of which Jeekel [2001] listed among Rhinocricidae , Spirobolida or even Juliformia of uncertain status. Two particularly enigmatic species, “ Julus ” roissyi Leguillou, 1841 and “ Julus ” doreyanus Gervais, 1847 , come from New Guinea, the former taxon totally without a locality. Only the name of the latter species may represent a hint at Port Dorey, harbour of Manokwari, Doberai Peninsula, Indonesia.

In addition, “ Rhinocricus ” dimissus Silvestri, 1895 was described from “Andai”. As all historic museum collections of the time also stem from near the settlement of Manokwari, S0°55’, E134°01’, the geographic provenance of that species seems to be clear. Likely the same concerns “ Julus ” roissyi as well. “ Rhinocricus ” granti Hirst, 1914 is known from near Mimika River, E136°30’, S4°30’, south of Mount Puncak Jaya, the highest peak of New Guinea, rather close to the town of Timika, Indonesia. “ Dinematocricus ” exul Chamberlin, 1920 is from “Djamna”, the old name of Jamna Island, S2°01, E139°15, off the northern coast of New Guinea, between Sarmi and Javapura, Indonesia.

“ Dinematocricus ” fratrellus Chamberlin, 1920 and “ D. ” permundus Chamberlin, 1920 , are both from Manokwari again, the capital city of West Papua Province of Indonesia. Although no identified rhinocricid seems to have ever been recorded from the Onin Peninsula, because the risk of falling in synonymy seems to us too high, we refrain from labeling our Papuan Propodobolus species before at least some of the available type material of old dubious taxa becomes revised, and an iconography published. This would allow us to properly compare the types to our description and illustrations.

Propodobolus spp. share virtually the same, highly characteristic structure of the posterior gonopod not only with the genus Australocricus Jeekel, 2001 , with seven species from eastern Australia [ Jeekel, 2001], but also with some Eurhinocricus forms from the Antilles [ Bond, Sierwald, 2002]. As this is likely to be evidence of a convergent evolution of that structure, the main distinction between the former two genera, both Australasian, remains the absence of a marked/high, basally constricted, central process on the anterior gonopod sternum in Propodobolus , vs. its presence in Australocricus .

Figures

Figs 1–9. Propodobolus sp., # from Onin Peninsula. 1, 2 — anterior part of body, lateral and ventral views, respectively; 3 — middle part of body, lateral view; 4 — body segments 8–13, dorsal view; 5 — caudal part of body, lateral view; 6, 7 — anterior gonopods and left posterior gonopod, anterior and posterior views, respectively; 8, 9 — right posterior gonopod, anterior and posterior views, respectively. Designations explained in text. Pictures by K.V. Makarov, taken not to scale. Рис. 1–9. Propodobolus sp., # с полуострова Онин. 1, 2 — переднЯЯ часть тела, соответственно сбоку и сниЗу; 3 — cреднЯЯ часть тела, сбоку; 4 — туловиЩные сегменты 8–13, сверху; 5 — ЗаднЯЯ часть тела, сбоку; 6, 7 — передние гоноподы и левый Задний гонопод, соответственно спереди и сЗади; 8, 9 — правый Задний гонопод, соответственно спереди и сЗади. ОбЪЯснениЯ обоЗначений в тексте. Фотографии К.В. Макарова, снЯты беЗ масШтаба.