Riotintobolus mandenensis Wesener,

Wesener, Thomas, Enghoff, Henrik & Sierwald, Petra, 2009, Review of the Spirobolida on Madagascar, with descriptions of twelve new genera, including three genera of ' fire millipedes' (Diplopoda), ZooKeys 19 (19), pp. 1-128: 51-52

publication ID 10.3897/zookeys.19.221

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Riotintobolus mandenensis Wesener

sp. n.

Riotintobolus mandenensis Wesener  , sp. n.

Material examined: 1 ♂, 16 ♀, 20 imm. Holotype: 1 ♂ (36 mm long, dissected), FMMC W040 C, Province Toliara, Mandena , littoral forest on sand, 34 m, 24°57.260’ S, 46°59.499’ E, leg. T. Wesener et al., 02.VI.2007GoogleMaps  . Paratypes: 5 ♀, 5 imm., FMMC W039 C, same data as holotypeGoogleMaps  ; 1 ♀, 2 imm., CAS W039View Materials C, same data as holotypeGoogleMaps  ; 1 ♀, 2 imm., ZMUC W39View Materials C, same data as holotypeGoogleMaps  ; 1 ♀, 2 imm., ZMH W39View Materials C, same data as holotypeGoogleMaps  ; 1 ♀, 2 imm., ZSM W039View Materials C, same data as holotypeGoogleMaps  .

Other material examined: 7 ♀, 7 imm., W039C, same data as holotype, University Antananarivo.

Differential diagnosis: the size and special colour pattern are unique for Malagasy millipedes. The gonopods of this species are similar in some aspects to those of R. minutus  sp. n. and R. anomalus  sp. n., but the posterior gonopods are of a unique shape.

Description. Measurements: holotype with 41 podous and 2 apodous rings, 36 mm long, 3.1 mm wide. Females with 41–43 podous and 0–2 apodous body rings, 37–43 mm long, 4.2–4.4 mm wide.

Coloration black, dorsally with an extraordinary wide, light brown stripe ( Fig. 24AView Figure 24). Posterior half of collum dorsally black ( Fig. 26AView Figure 26). Head, legs and antennae light brown. Eyes with 16–20 almost fused ocelli arranged in 4 or 5 rows ( Figs 26A, CView Figure 26). Antennae protruding back to body ring 2 ( Fig. 26AView Figure 26). Legs without tarsal pads. Male legs reach 0.7 times, female legs 0.6 times body diameter. Preanal process sharp-edged, straight, protruding above anal valves ( Fig. 26BView Figure 26). Anal valves small, between anterior part and lips with a deep groove, margin towards groove sharpedged ( Fig. 26BView Figure 26).

Anterior gonopod sternite basally wide, apically elevated into a lobe with a triangular, well-rounded tip ( Fig. 26IView Figure 26). Sternite tip almost as high as mesal process of coxite; latter relatively slender, elongated, longer than sternite ( Fig. 26IView Figure 26). Telopodite on posterior side apically with a large triangular, retrorse process ( Fig. 26KView Figure 26). Process projecting above coxite and telopodite ( Fig. 26KView Figure 26).

Posterior gonopods telopodite laterally with a single, large, finger-shaped process ( Fig. 26J, xView Figure 26). Second small projection, where sperm canal is discharging, is located close to apex ( Fig. 26M, yView Figure 26). A large, bi-lobical membrane present apically. Membrane apically three times wider than basally ( Fig. 26L, zView Figure 26). A small, white, swollen area ( Fig. 26MView Figure 26) is also located basally of membrane.

Intraspecific variation: females exist in different size classes. The presence of apodous rings in front of the telson in mature specimens hint to the existence of postmaturity moults.

Distribution and ecology: this species was only collected in the littoral rainforest on sand of Mandena ( Fig. 25View Figure 25). Only 160 ha of this forest will remain after a large-scale mining project ( Vincelette et al. 2003). All specimens were collected directly on the root layer under a thin layer of leaf litter. Disturbed specimens often did not curl into a spiral but remained motionless and stiff like a stick even when picked up. Because of their black/light-brown colour pattern ( Fig. 24AView Figure 24), specimens of R. mandenensis  were quite difficult to detect against the background consisting of sand with some darker top soil inclusion. The giant pill-millipede species Sphaeromimus inexpectatus Wesener & Sierwald, 2005  is also only known from a small area surrounding Mandena (Wesen- er and Sierwald 2005).

Etymology: mandenensis  , adjective, refers to the only area where this species lives, the littoral forest of Mandena.


California Academy of Sciences


Zoological Museum, University of Copenhagen


Zoologisches Museum Hamburg


Bavarian State Collection of Zoology