Pleonoporus tanzanicus, Enghoff & Akkari, 2022

Enghoff, Henrik & Akkari, Nesrine, 2022, A new species of the hitherto monospecific genus Pleonoporus Attems, 1938 (Diplopoda, Spirostreptida, Odontopygidae), ZooKeys 1117, pp. 189-202 : 189

Pleonoporus tanzanicus sp. nov.

Figs 1 , 2 , 3 , 4

Diagnosis.

Differs from P. robustus , its only congener, by having a long, slender, disto-laterad hooked spine on the gonopodcoxa; in P. robustus , there is no trace of such spine.

Material examined.

(total 5 ♂♂, 1 (juvenile) ♀). Holotype. Tanzania • ♂; Singida Region, Manyoni District, Kilimatinde ; 05°50'S, 34°58'E; 26 Jan. - 08 Feb. 1911 ; E. Obst leg.; verbatim label text: "Ostafr.-Exp. d. Hamb. Geogr. Ges. Kilimatinde , Landschaft Ugogo Dr, E. Obst leg., 26.I -8.II. 1911. Geogr-. Ges. ded. 3.x.1912 "; (ZMH) Paratypes. Tanzania • ♂; Singida Region, Manyoni District, Saranda-Sawa [here understood as the village of Saranda ca. 14 km N of Kilimatinde]; 05°43'S, 34°59'E; 15-16 Feb. 1911 ; E. Obst leg. ZMH-A0016675; NHMD 621850; verbatim label text: "Ostafr.-Exp. d. Hamb. Geogr. Ges. Ugogo und Turu, Saranda-Sawa, Dr. E. Obst leg., 15.-16.II. 1911, Geogr-. Ges. ded. 3.x.1912 "; additional labels: " Spinotarsus ?, R.L. Hoffman det. 1966", " Odontopygidae :?n.gen. oder viell. Spinotarsus ?" [label by Krabbe?] • ♂; Singida Region, Manyoni District, Mahalala [here understood as the village of Muhalala ca. 11 km WNW of Kilimatinde]; 05°47'S, 34°53'E; 12-14 Feb. 1911 ; E. Obst leg.; ZMH-A0016676; verbatim label text: "Ostafr.-Exp. d. Hamb. Geogr. Ges. Mahalala, Landschaft Ugogo leg. Obst, 12/14.II. 1911" • 2 ♂♂, 1 (juvenile) ♀; same collection data as holotype, ZMH- A0016676; 1 ♂, same collection data as holotype, NHMW MY 10277 (♂) .

Description.

(males). Size. Length ca. 8 cm. Diameter 5.5-6.0 mm. 60-62 podous rings, no apodous rings in front of telson.

Colour (Fig. 1 ). Quite faded after 111 years in alcohol. Head below antennal sockets, antennae and legs yellowish brown. Head above antennal sockets, collum, rings 2 and 6 almost uniformly dark brown. Other body rings greyish or whitish, with some irregular darker blotches; posterior part of metazonites amber. Traces of a pattern can be seen in some specimens, in which the prozonites from midway between the ozopore level and the midline are yellowish, white in the anterior half and a contrasting blackish in the posterior half; anterior part of body with traces of a narrower dorsal longitudinal light band flanked by a darker coloured zone.

Head. Area below supralabral setae vertically wrinkled, otherwise smooth; parietal furrow distinct, interocular furrow very faint; supralabral setae abraded and uncountable in most specimens, but six setae/sockets can be seen in some; eyes extending to medial tangent to antennal sockets. Mandibular stipes with a not very pronounced disto-ventral lobe; distal margin very shallowly emarginated.

Collum. With rectangular lateral lobes; a marginal furrow and one further furrow extending almost halfway to dorsal midline, two short furrows between them.

Body rings. Unvaulted; prozonites with fine, finely punctate ring furrows; suture straight, simple; metazonites with rather dense, deep longitudinal furrows in ventral part; on anterior body rings the furrows reach almost to ozopores level, further back they stop well below the pores and are not so deep. Ozopores starting on ring 5, visible as black dots (Fig. 1C ). Limbus (Fig. 2F ) with pointed, triangular lobes, lobes slightly longer than broad at base.

Telson (Fig. 1B ). Preanal ring not keeled. Anal valves smooth, with well-developed dorsal spine and raised margins; no ventral spine or “corner”; setae not visible, no ravelins. Subanal scale simple.

Legs. Length ca. 0.8 × body diameter. Prefemoral and tibial pads present on all legs from pair 6 backwards.

First pair of legs (Fig. 2C-E ). With short, broad, regularly rounded lobes, almost semicircular in ventral view. Ca. 6 long coxosternal setae (CXS) in a group lateral to, and well separated from, prefemoral lobe. Prefemora with two to three mesapical setae (APS) and ca. five lateral setae (LPS).

Sternum 9 (Fig. 2B, C ). Massive; in anterior view triangular with a basal non-sclerotized incision resulting in an inverted V-shaped appearance; on posterior side strongly swollen.

Gonopod coxa (Fig. 3 ). In anterior view with a large hump (hu) on lateral margin; a long, slender, disto-laterad hooked spine (LCS) originating from distal part of hump. Mesal margin of proplica (PP) slightly sinuous, proplical lobe hidden from view by process (msp) from metaplica. Metaplica (MP) with large flange (MF) extending almost until half-height ofcoxa, ending abruptly but without a distal process. Metaplica distal to flange with a large horizontal shelf (ms) across mesal surface, ending posteriorly in triangular tooth (mst); a rounded knob (mk) projecting from mesal margin of metaplica, facing mst. Further distally, a lateral extension of the metaplica gives rise to a long, stout, transverse spine (mts) which curves posteriad across mesal surface ofcoxa, ending between mst and mk. Distal part ofcoxa, cucullus (CU) sensu Enghoff (2022), in anterior view resembling a bird’s head with the curved “beak” pointing meso-basad; a long, slender, slightly curved spine (msp) originating from base of cucullus on anterior side, extending basad along mesal margin of proplica.

Gonopod telopodite (Fig. 4 ). Arculus (ARC) 90°; torsotope (TT) compact, with a rounded torsotope lobe (TL); no post-torsal spine. Solenomere (SLM) much longer than telomere, slender, whip-like, without a basal solenomeral spine, but with a small tongue-like flap (fl) at base; without any other process or modification. Telomere (TM) complex; basal shape a broad sheet curved in a semicircle and with the lateral margins partly folded in. Telomere distally separating into two lamellae, anterior lamella (al) with largely smooth margins, posterior lamella (pl) coarsely and irregularly serrate.

Figures

Figure 1. Pleonoporus tanzanicus sp. nov. A paratype ♂, habitus (ZMHZMH- 0016676) B holotype ♂ (ZMH- 0016675) Last four body rings and telson C paratype ♂, head and first nine body rings (NHMW MY 10277). Scale bars: 5 mm (A); 1 mm (B, C).

Figure 2. Pleonoporus tanzanicus sp. nov., paratype, ♂ (NHMD 621850) A, B sternum 9 A anterior view B ventral view C-E first pair of legs C anterior view D sublateral view E ventral view F limbus. Abbreviations: APS = mesapical prefemoral setae; CXS = coxosternal setae; LPS = lateral prefemoral setae. Scale bars: 0.2 mm (A-E); 0.02 mm (F).

Figure 3. Pleonoporus tanzanicus sp. nov., paratype, ♂ (NHMD 621850), left gonopodcoxa A anterior view B posterior view C mesal view. Abbreviations: CU = cucullus; hu = lateral hump; LCS = lateral coxal spine; MF = metaplical flange; mk = metaplical knob; MP = metaplica; ms = metaplical shelf; msp = metaplical spine; mst = metaplical shelf tooth; mts = metaplical transverse spine; PP = proplica. Scale bars: 0.2 mm.

Figure 4. Pleonoporus tanzanicus sp. n., paratype, ♂ (NHMD 621850), left gonopod Gonopod telopodite A anterior view B posterior view (basomere partly covered by mounting tape (orange )) C ventral (apical) view D basal (dorsal) view E mesal view F tip of solenomere. Abbreviations: al = anterior lobe of telomere; ARC = arculus; fl = basal flap of solenomere; pl = posterior lobe of telomere; SLM = solenomere; TL I = torsotope lobe; TM = telomere; TT = torsotope. Scale bars: 0.2 mm (A-E); 0.02 mm (F).