Zoosphaerium darthvaderi Wesener & Bespalova, 2010

Wesener, Thomas, Bespalova, Ioulia & Sierwald, Petra, 2010, Madagascar’s living giants: discovery of five new species of endemic giant pill-millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae: Zoosphaerium), African Invertebrates 51 (1), pp. 133-133 : 148-152

Zoosphaerium darthvaderi Wesener & Bespalova , sp. n.

Figs 11–13 , 17D

Etymology: From the “Star Wars” character Darth Vader, whose helmet strongly resembles the anal shield of this species ( Fig. 11D ).

Differential diagnosis: Differs (at least in the male) from all other Malagasy Sphaerotheriida in the presence of a strongly bell-shaped anal shield ( Figs 11A, D ). Male gonopore large, strongly sclerotised and protruding from the coxa ( Fig. 11F ), a unique character within the Sphaerotheriida . The posterior telopods of Z. darthvaderi resemble those of members of the Z. coquerelianum species-group ( Wesener 2009), but the fixed finger, as well as the inner lobes, are more slender than in any other member of the group ( Figs 12D–F ). The anterior telopods are elongated ( Figs 12A–C ), resembling those of members of the Z. neptunus species-group ( Wesener & Wägele 2008). The male stridulation rib is strongly reduced, almost invisible ( Fig. 12A ).

Description:

Male.

Body length: Holotype: length 20.8 mm, width of thoracic shield 9.4 mm, height of thoracic shield 5.2 mm.

Habitus: Small, mostly glabrous pill-millipede. Tergites on posterior margin with conspicuous rows of longer hair ( Fig. 11A ).

Colouration: Some discolouration may have occurred because of preservation in alcohol. Tergites are green-brown with an ochre rim at posterior edge of tergite.Anal shield one solid colour, browner than tergites. Legs and antennae jade-green, legs with yellow tips. Head and collum are dark leafy green.

Head: Eyes with 65–70 ocelli ( Fig. 11A ). Antennae long and thin, with cylindrical joints ( Fig. 13A ). Length of antennomeres: 1>2>3=4>5<6. First antennomere without groove or sensilla basiconica. Sclerotised teeth present on antennomeres 1–3. Apical disc bearing around 20 sensory cones ( Fig. 13B ). Mouthparts not dissected. Collum with just a few hairs around perimeter, median part glabrous.

Thoracic shield: Surface like tergites.

Tergites: Surface of tergites covered with numerous minute pits. Paratergites not projecting posteriorly.

Endotergum: Single, sparse row of marginal bristles reaching edge, or a little past edge, of margin. Cuticular impressions absent. Internal section with short triangular spines and few isolated long bristles ( Fig. 17D ).

Anal shield: Pronounced bell shape ( Figs 11D, E ); top of bell featuring a prominent hump densely covered in very short hairs. Underside with 2 black locking carinae, posterior one twice as long as anterior one, latter slightly curving posteriorly towards margin of anal shield. Carinae separated by a space about as long as 0.5 length of anterior carina.

Legs: Tarsi 1 with 4, 2 with 6, 3 with ca 7 ventral spines. First 2 leg pairs without an apical spine. Tarsi of legs 3–21 with an apical spine and 8–10 ventral spines. In leg 10, femur 1.87×, tarsi 3.87× longer than wide ( Fig. 11C ).

Stigmatic plates: First plate with triangular lobe. Lobe short and stout, and slightly curving towards coxa ( Fig. 11B ).

Female. Unknown.

Male sexual characters: Gonopore unusual, covered by an extremely large plate of 3 sclerotised sections with membranous parts between them ( Fig. 11F ). Two sections large and equal in size, located next to each other (one mesally, one laterally) and together covering width of gonopore.Above them, a small apical sclerotised section covered by a large membranous region gives gonopore a flat top. Gonopore plate protruding prominently above coxa ( Fig. 11F ). Anal shield featuring a prominent hump covered in a carpet of very short hairs ( Fig. 11D ).

Anterior telopods ( Figs 12A–C ): Harp secondarily (?) reduced, with one barely visible stridulation rib. Second podomere process short, portion facing third podomere mostly covered with a mound of sclerotised spots. Below, spots at base of projection with a sclerotised spine. Third podomere possessing cavity which faces second podomere. Cavity basally deep, apically containing a large mound of sclerotised spots, laterally of cavity one small sclerotised spine. No sclerotised, crenulated teeth anywhere on anterior telopods, nor brown sclerotised spot.

Posterior telopods ( Figs 12D–F ): Movable finger thick (2.0× longer than wide), apically weakly curved and barely tapering. Shallow meso-apical cavity with 4 sclerotised spines, 2 positioned apically, 2 (1 short one positioned below 1 long one) in middle of cavity. On apical posterior margin are 5 or 6 large, sclerotised, crenulated teeth, 1 isolated and located much more basally than others. Fixed finger almost as long as movable finger, curved, very slender (9.2× longer than wide, when length measured from base of projecting second podomere to tip). Sharp lobe and long sclerotised spine located laterally at base of fixed finger. Tip of fixed finger latero-apically covered with a mound of sclerotised spots. Chelae almost completely glabrous, except for a few isolated setae on lateral area of posterior side of second podomere. Inner lobes of syncoxite very slender. Tips of inner horns curving inward.

Holotype: ơ ( FMNH-INS 7884 ). MADAGASCAR: Antananarivo Prov.: R.S d’Ambohitantely, 24 km NE Ankazobe , disturbed transitional mossy forest, 1450 m, 18°10.1'S: 47°16.6'E, S.M. Goodman, pitfall traps, 7–12.xii.1997.

Paratypes: immature 3ơ ( FMNH-INS 7884 , 8185 , 8187 ) same data as holotype .

Distribution & Ecology: Z. darthvaderi is currently only known from mossy forests of Ambohitantely ( Fig. 2 ).

Figures

Fig. 11. Zoosphaerium darthvaderi sp. n., holotype: (A) habitus, lateral view; (B) coxa and prefemur of first left leg with first stigmatic plate, posterior view; (C) 9th left leg, posterior view; (D) anal shield, lateral view; (E) anal shield, dorsal view; (F) male second right coxa and prefemur with strongly sclerotised gonopore, posterior view. Roman numerals refer to number of tergite.Abbreviations: c – collum (tergite 1), h – head, AS – anal shield, Cx – coxa, Go – gonopore, Pre – prefemur, St – stigmatic plate, th-s – thoracic shield (tergite 2). Scale bars: (A) = 10 mm, (B–F) = 1 mm.

Fig. 12. Zoosphaerium darthvaderi sp. n., holotype: (A–C) left anterior telopod: (A) anterior view, (B) lateral view, (C) posterior view; (D–F) posterior telopods: (D) anterior view, (E) posterior view, (F) right chela, posterior view. Roman numerals refer to number of podomere. Abbreviations: cr-t – crenulated, sclerotised teeth, IH – inner horns, IL – inner lobes, s-ps – sclerotised spots, SR – stridulation rib. Scale bars = 1 mm.

Fig. 13. Zoosphaerium darthvaderi sp. n., holotype, left antenna, SEM: (A) lateral view, (B) apical view on disc.

Fig. 17. Endoterga of tergites 10, arrows point to cuticular impressions: (A) holotype of Zoosphaerium muscorum sp. n., (B) holotype of Z. bambusoides sp. n., (C) holotype of Z. tigrioculatum sp. n., (D) holotype of Z. darthvaderi sp. n., (E) holotype of Z. heleios sp. n.Abbreviations: ci – cuticular impressions, IA – inner area with spines and long setae, mr – marginal ridge, mb – marginal bristles.

Fig. 2. Distribution map of new Zoosphaerium species.