Globanus drewesi, VandenSpiegel & Shelley & Golovatch, 2020

VandenSpiegel, Didier, Shelley, Rowland M. & Golovatch, Sergei I., 2020, The millipede genus Globanus Attems, 1914, endemic to Sao Tome and Principe, with the description of a new species (Diplopoda, Spirostreptida, Spirostreptidae), ZooKeys 930, pp. 61-74 : 61

Globanus drewesi sp. nov. Figures 2 , 3

Type material.

Holotype ♂, Republic of São Tomé and Príncipe, São Tomé Island, Morro Provaz Ridge, road to Lagoa Amelia, alt. 1475 m, 3.III.2010, 0°16 ’58” N, 6°35 ’12.5” E, Bob Drewes leg. (CASENT9032626).

Paratypes: 1 ♂, 6 ♀♀, Republic of São Tomé and Principe, São Tomé Island, Morro Provaz Ridge, Headwaters of Rio do Oro, alt. 1240 m, 3.III.2010, 0°17 ’3.8” N, 6°35 ’57.5” E, Bob Drewes leg. (CASENT9032626).

Etymology.

Honours Bob Drewes, the collector.

Diagnosis.

Distinguished from other species of the genus by the acuminate distal prolongation of the gonopod proplica. Post-torsal process of telopodite with two attached lamellae; apex rotated 360°ending in a tongue-shaped process.

Description.

Holotype, adult male with 52 body rings (including preanal ring), length ca 65 mm (curved and broken), maximum body diameter 4.23 mm.

Colour (in alcohol) predominantly brownish; prozonae yellowish brown; metazonae, legs, and antennae dark brown.

Head without modifications, smooth and polished, interantennal isthmus 1.11 mm, interocellarial isthmus 1.15 mm; antennae short (55% of maximum body diameter), extending up to posterior edge of collum; sensory pits on antennomeres 5 and 6 present, on 5th antennomere smaller. Eyes reniform, ommatidia arranged in five series: 9-8-7-6-4 = 34, counted from behind (Fig. 2C ). Gnathochilarium with a transverse row of about 10 setae along distal margin and 6 large setae on each lingual lamella; mentum elongate-triangular with a few setae and a well-marked submedian transverse groove (Fig. 2D , sg).

Collum subcylindrical, smooth, lateral ends with three submarginal striae (Fig. 2B ).

Body rings circular (height/width ratio of midbody rings 0.98-1.0), no legless body rings in front of telson. Prozonae smooth, suture between pro- and metazonae straight. Metazonae equal in diameter to prozonae; metazonital striae present below ozopore level; ozopores starting with segment 6, rather vague, located just behind suture on midbody segments (Fig. 2B , oz). Paraprocts convex, distal margins set off by a submarginal groove. Hypoproct not fused to preceding segment.

First pair of male Iegs as shown in Fig. 2F , with 5 or 6 setose tubercles laterally; each prefemur with a prominent basal projection on anterior side and with short setae medially. Second pair of legs and penes as in Figure 2E . Walking legs rather short (length 61% of midbody diameter, only tarsi visible from above when stretched; Fig. 2E, H ), distal third with ventral tibial pads extending to proximal third of tarsi. Tarsal claws long and curved, each with a small basal seta (Fig. 2I, s ).

Gonopods with a small sternum; proplica (pp) slender, with an acuminate distolateral spine and a field of short setae proximal to it. Metaplica (mp) slender proximally, expanded distally to form a latero-apical metaplical process (lap), slightly projecting outside the body when at rest (Fig. 3A-C ). Telopodite as shown in Figure 3D, E , placed on anterior side of gonopod, antetorsal process (atp) long and slender, originating near arculus. Torsate region comprising less than half of telopodite length, distal third giving rise to a flattened blade (fb) and, beyond this, to a subtriangular projection (sp) (Fig. 3D ). Apex rotated 360° ending in a tongue-shaped process. Prostatic groove running straight to tip of solenomere, ending just before the tongue-shape process level to a small digit (Fig. 3F ).

Paratype male agrees with holotype in all structural details, but females larger (up to 80 mm in length and ca 6 mm in diameter), with short legs (ca 60% of midbody diameter) devoid of tibial pads; the number of body rings also varies between specimens (up to 56 body rings including preanal ring). Vulvae placed vertically inside segment 3; no setae on vulvae.

The other characters agree with those of the holotype.

Distribution.

The species seems to be endemic to São Tomé Island.

Relationships.

Although the three species of Globanus are externaly very similar, the gonopod structure suggests that the new species is closer to G. marginescaber . In both species, the median lamella of the telocoxite shows a well-marked distal proplica spine, which is absent in G. integer .

Figures

Figure 2. Globanus drewesi sp. nov., ♂ paratype. A habitus, lateral view B collum and segments 2 - 6, lateral view C frontal view of head D gnathochilarium E midbody transversal section F first pair of legs, oral view G second pair of legs, oral view H midbody legs, oral view I midbody claw, caudal view. Abbreviations: me = mentum, pe = penes, pfp = prefemoral process, s = seta at base of claw, sg = submedian transverse groove. Scale bars: 5 mm (A); 1 mm (B) 1 mm (D, E); 500 µm (C, D, F, G); 200 µm (H); 50 µm (I).

Figure 3. Globanus drewesi sp. nov. ♂ paratype. A, B left coxite, oral and caudal views, respectively C tip of left coxite, caudal view D, E left telopodite detached, anterior and posterior views, respectively F tip of left telopodite, posterior view. Abbreviations: atp = antetorsal process, bs = basomere, fb = flattened blade, lap = latero-apical process, map = meso-apical metaplical process, mp = metaplica, pp = proplica, ps = proplica spine, px = paracoxite, sp = subtriangular projection. Scale bars: 200 µm (A, B, D, E); 100 µm (C, F).