Zoosphaerium voeltzkowianum (de Saussure & Zehntner, 1897 )

Wesener, Thomas & Wägele, Johann-Wolfgang, 2008, The giant pill-millipedes of Madagascar: revision of the genus Zoosphaerium (Myriapoda, Diplopoda, Sphaerotheriida), Zoosystema 30 (1), pp. 5-85 : 42-0

publication ID	https://doi.org/ 10.5281/zenodo.5391729
persistent identifier	https://treatment.plazi.org/id/AA451447-2B29-FFC0-FCCA-FA23FB9C9E14
treatment provided by	Marcus
scientific name	Zoosphaerium voeltzkowianum (de Saussure & Zehntner, 1897 )
status

Treatment

Zoosphaerium voeltzkowianum (de Saussure & Zehntner, 1897) View in CoL

( Figs 24-29 View FIG View FIG View FIG View FIG View FIG View FIG )

Sphaerotherium voeltzkowianum de Saussure & Zehntner, 1897 : pl., fig. 21; 1901: 43, pl. 39, figs, 7, pl. 40, fig. 3; 1902: 2, pl. 14, figs 8-8a, pl. 1, figs 3-3a.

Sphaerotherium imbecillum de Saussure & Zehntner, 1897 : pl., fig. 20, n. syn.

Sphaerotherium globulus de Saussure & Zehntner, 1902: 34 , n. syn.

Zoosphaerium voeltzkowianum View in CoL – Jeekel 1999: 12 (lists species name). — Enghoff 2003 (lists species name).

TYPE MATERIAL. — Zoosphaerium voeltzkowianum : Madagascar, leg. Musée de Genève (de Saussure & Zehntner [1902: 3] mentioned “plusieurs individus de Nosy Bé, récoltés par le docteur Voeltzkow”), ♂ lectotype (here designated) ( MNHN CB04 View Materials ) ; same data as lectotype, 2 ♀♀ paralectotypes .

Zoosphaerium imbecillum : Madagascar, Nosy Bé, 2 ♂♂ syntypes ( MNHN CB031).

Zoosphaerium globulus : Madagascar, Nosy Bé, 4304, leg. 188, ♂ holotype (broken) (MNHN CB02).

OTHER MATERIAL EXAMINED. — Madagascar. Province Antsiranana, Nosy Bé, Parc national de Lokobe, 4.9 km 12 ° ESE Hellville, 13°24’ ”S, 48°18’27”E, 0-200 m, rainforest, pitfall trap, coll. D. Andriamalala, C. Griswold, H. Ratsirarson & D. Silva, 1.II.2003, 1 ♂ (BLF 8000).

DIAGNOSIS. — Up to 30 mm (literature: 41 mm, de Saussure & Zehntner 1902) long. Brown, posterior margin of tergites darker brownish, some specimens with traces of former green coloration. Surface of tergites glabrous, at high magnification small dot-like impressions become visible. Anal shield well-rounded ( Fig. 24A View FIG ), glabrous. Apical antennomere with 4 sensory cones ( Fig. 28A View FIG ). Third joint of posterior telopod broad, with well-rounded tip. Posterior side with around sclerotized teeth and 3 sclerotized spines ( Figs 24L View FIG ; 2 G; 2 H View FIG ). Second joint with long and slim, weakly curved immovable digit, basally with 1 spine, distally at inner margin with numerous sclerotized spots ( Fig. 24K View FIG ). Two stridulation ribs on each male harp and 2 on each side of female washboard ( Figs 24F, H View FIG ; 2 E; 2 E View FIG ). Anal shield with 2 locking carinae, first small, second more than 4. times longer than first ( Figs 24D View FIG ; 2 D; 2 C View FIG ). Operculum of vulva minute, female possibly immature ( Fig. 24E View FIG ).

SIMILAR SPECIES

All species in the coquerelianum- group show similar shaped posterior telopods and female vulvae. Zoosphaerium voeltzkowianum features nevertheless a unique combination of characters, as 4 antennal sensory cones, 2 stridulation ribs on the male harp, glabrous collum, absence of sclerotized teeth on the third joint of anterior telopods and the length of the posterior locking carina.

DESCRIPTION

Body measurements: males (specimens): length up to 30.2 (largest broken), width of thoracic shield up to 1., height of thoracic shield up to 9.2. Females (2 specimens): length up to 27.2 (literature 41.0 mm), width up to 13.7, height up to 7.9.

Habitus: elongated, not high ( Figs 24A View FIG ; 2 A; 2 A View FIG ). Tergites and anal shield without hair, but surface of tergite and anal shield at high magnification covered with small, irregular circular pits

Coloration: faded in alcohol. Tergites brown, posterior margin with thin dark brown line. Sometimes traces of shiny green coloration visible. Head, antennae and tips of legs green.

Head: posterior margin of head towards collum without small hair.

Antennae: length of joints: 1>2>3=4= << ( Fig. 28A View FIG ), sixth joint longest, of cylindrical shape ( Fig. 28A View FIG ), apically with 1 row of sensilla basiconica, on tip bearing a disc with 4 () sensory cones ( Fig. 28A View FIG ). First joint remarkably broader than the others, short and with one groove ( Fig. 28A View FIG ). Sclerotized teeth at the base of joints 1-3, reaching not up to apical border. First joint apically on one side with 1 or 2 rows of sensilla basiconica ( Fig. 28B View FIG ).

Mandible: with rows of pectinate lamellae; number of teeth decreasing proximad ( Fig. 27A View FIG ). Condylus with 2 strongly developed steps near apical margin, apical step stronger developed ( Fig. 27A View FIG ).

Gnathochilarium: ventral side with numerous bristles ( Fig. 27B View FIG ). Bump with 4 sensory cones, located together lateral of palpi ( Fig. 27D View FIG ). Vale on backside of palpi with numerous sensory cones ( Fig. 28C View FIG ). Two different types of sensory uvulae on central pads: long, cylinder-shaped ones with single pit in their middle and more plain ones without pit ( Figs 27C View FIG ; 28C View FIG ).

Collum: anterior and posterior margin with some long hairs arranged in one row. Remaining part of collum glabrous.

Thoracic shield: surface structured like those of tergites ( Fig. 24A View FIG ).

Tergites: posterior paratergite margins projecting slightly posteriorly, in last 2 paratergites almost straight ( Fig. 24A View FIG ).

Endotergum: internal section with short spines and isolated bristles. One row of large circular cuticular pattern between marginal ridge and internal area ( Fig. 29A, C, D View FIG ). External 1 row of marginal bristles, standing closely to one another. Bristles scaly ( Fig. 29B View FIG ), protruding 1/2-2/3 towards posterior margin ( Fig. 29A View FIG ).

Anal shield: well-rounded, neither bell-shaped nor tapered ( Figs 24A View FIG ; 2 A; 2 A View FIG ). Like tergites completely covered with numerous, small, irregular pits. Underside carrying 2 well-developed black locking carinae on both sides, anterior 1 small, but well-developed, projecting posteriorly slightly towards anal shield margin. Posterior carina more than 4. times longer than first, straight. Locking carinae separated from one another by a distance equal to 1/3 of shorter carina length ( Figs 24D View FIG ; 2 D; 2 C View FIG ).

Legs: first tarsi with 4-, second with -8, third with 8 or 9 long ventral spines. First 2 tarsi with weakly curved claws and without apical spine.Tarsi 3-21 with curved claws, 9-12 ventral spines and an apical spine. Ventral spines dispersed through whole inner margin of tarsus. Ninth leg femur 2.3 times longer than wide, tarsi.1 times longer than wide. Femora with crenulated ridge of medium length ( Figs 24C View FIG ; 2 B View FIG ).

Stigma-carrying plate: first stigma-carrying plate lobe long and well-rounded, surmounting apical edge of coxa 1. Lobe curved towards coxa, broad and slimmer at pointed tip ( Figs 24B View FIG ; 2 C; 2 B View FIG ).

Female sexual characters: only immature females available. Subanal plate with a washboard consisting of well-developed stridulation ribs, 2 ribs on each side. Stridulation ribs symmetrical, broad. Ribs short, ending far away from posterior margin ( Fig. 24F View FIG ). Vulva small, covering fewer than 1/2 of coxa. Operculum low, ending before apical coxa margin. Apical margin of operculum medially weakly notched, with 2 rounded lateral tips ( Fig. 24E View FIG ). Inner plate reaching up to 1/3 operculum height ( Fig. 24E View FIG ).

Male sexual characters: male gonopore covered with single, large, sclerotized, undivided and rounded plate. Apical part of plate membranous. Gonopore covering 1/3 of coxal height and more than 1/2 of coxal width ( Fig. 24G View FIG ). Anal shield well-rounded.

Anterior telopods: first joint with a stridulation harp and two stridulation ribs. Both ribs straight and well-developed. Inner rib reaching only 2/3 of lateral rib length ( Fig. 24H View FIG ). Second joint on posterior side with lobe like, weakly curved process with rounded edges ( Fig. 24I, J View FIG ), protruding almost as high as third joint. Process towards third joint apically with sclerotized spots ( Fig. 24J View FIG ). Tip of third joint strongly bending inwards, protruding twice as high as second joint process. Joint with a cavity juxtaposed to second joint process. Apical margin of third joint well-rounded, towards cavity with numerous sclerotized spots and 2 spines.Two additional spines located closely to tip ( Fig. 24I, J View FIG ). Syncoxite on both sides with only few, isolated hairs ( Fig. 24H View FIG ).

Posterior telopods: third joint weakly curved, becoming slightly slimmer towards tip ( Fig. 24K View FIG ). Hollowed-out margin towards second joint with 3 sclerotized spines ( Figs 24K View FIG ; 2 H; 2 G View FIG ), on posterior aspect with one row of c. sclerotized teeth ( Figs 24L View FIG ; 2 G; 2 H View FIG ). Second joint process slim, almost as long as third joint, tip weakly curved. Anterior side of second joint process basally with one short sclerotized spine. Third joint on both sides basally with some hairs, on rest of surface hairs absent. Second joint on backside almost completely covered with long hairs, anterior side only basally with some long hairs. First joint on both sides with some hairs around its margin ( Fig. 24K, L View FIG ). Inner horns of syncoxite apically curved posteriorly. Tips sharp, whole horns covered with numerous small hairs.

INTRASPECIFIC VARIATION

Smaller specimens show almost no cavity on last joint of anterior telopods. Particularly in the small types of S. imbecillum the posterior telopods are slightly slimmer than in larger males ( Fig. 2 E, F View FIG ). A variation of the tip of the first stigma-carrying plate ( Figs 2 C; 2 B View FIG ) is visible, but to few material is available to make further studies on the intraspecific variation of this character.

DISTRIBUTION AND ECOLOGY

Only known from the island of Nosy Bé ( Fig. 23 View FIG ). Species collected together with two other species of Zoosphaerium .

CONSERVATION

The protection status of this species, obviously endemic to Nosy Bé ( Fig. 23 View FIG ), is unknown.

REMARKS

The synonymization of S. imbecillum and S. globulus with Z. voeltzkowianum was a difficult task, which needs a longer explanation. The correct identification of this species was not easy, because most of the specimens in the type series were immature, especially all specimens of S. imbecillum . The only existing specimen of S. globulus is furthermore in poor condition. Type series of both species did not include female specimens and the female specimen of Z. voeltzkowianum are obviously immature. The species were distinguished in the original description using the different size and surface structures on tergites as separating characters. The authors do not agree with this conclusion. De Saussure & Zehntner (1902) even observed the striking similarity in the telopods of S. imbecillum , S. globulus and Z. voeltzkowianum . The authors observed furthermore striking similarities in the structure of the endotergum ( Fig. 29 View FIG ). All differences mentioned by de Saussure & Zehntner (1897, 1901, 1902) can be explained with the different size of specimens. To make this issue even more complicated, the specimens determined as Sphaerotherium voeltzkowianum at the Senckenberg Institute and one female in the type series at the MNHN are not conspecific with the other two males and two females of the type series. In fact, these three specimens may even represent an undescribed genus different from Zoosphaerium . Sphaerotherium imbecillum and S. globulus were described in the same article (de Saussure & Zehntner 1902). In the text and the determination key, S. globulus is mentioned at first, but the plates of S. imbecillum and Z.voeltzkowianum were published five years before the publication of the description in 1897 (see Jeekel 1999 for a statement about this issue). Because of these facts, S. globulus and S. imbecillum are both proposed to be synonymous to Z. voeltzkowianum .