Zoosphaerium piligerum (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 : 7-2

publication ID	https://doi.org/ 10.5281/zenodo.5391729
persistent identifier	https://treatment.plazi.org/id/AA451447-2B38-FFD4-FCE5-FC18FB6D9AE3
treatment provided by	Marcus
scientific name	Zoosphaerium piligerum (de Saussure & Zehntner, 1897 )
status

Treatment

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

( Figs 34-37 View FIG View FIG View FIG View FIG )

Sphaerotherium piligerum de Saussure & Zehntner, 1897 : pl., figs 19-19a; 1902: 3, pl. 1, figs 4-4b.

Zoosphaerium piligerum View in CoL – Jeekel 1999: 11 (lists species name). — Enghoff 2003: 20 (lists species name).

TYPE MATERIAL. — Madagascar, I.1890, leg. Catat, ♂ holotype ( MNHN CB040).

OTHER MATERIAL EXAMINED. — Madagascar. Province Antananarivo, 3 km 41° NE Andranomay, 11. km 147° SSE Anjozorobe , 18°28’24’’S, 47° 7’3 ’’E, 1300 m, montane rainforest, - 13.XII.2000, coll. Griswold et al., general collecting, 1 ♂, 3 ♀♀ ( BLF 2 43) GoogleMaps ; 1 ♀ ( BLF 2371 ) GoogleMaps ; 1 ♀ ( BLF 2377 ) .

DIAGNOSIS. — Up to 3 mm long. Colour splendid blackish ( Fig. 19B View FIG ), younger individuals darkish green. Surface of tergites shiny, with few, small isolated hairs. Anal shield bell-shaped, in the male covered completely with short hairs, in the female with few small hairs. Antennomere 1-2 with sclerotized teeth ( Fig. 3 A View FIG ). Apical joint with 12-19 sensory cones ( Fig. 3 B View FIG ). All antennal joints without groove ( Fig. 3 A, B View FIG ). Posterior telopod third joint strongly curved, posterior side with up to 14 sclerotized teeth, a large, non-sclerotized lobe ( Fig. 34K View FIG ) and around 4 sclerotized spines. Second joint with long and slim immovable digit, strongly curved, basally with one large membranous lobe and a spine.Two stridulation ribs on male harp ( Fig. 34G View FIG ) and 1 or 2 on each side of female washboard ( Fig. 34E View FIG ). Anal shield with 2 locking carinae, first small, second 3-4 times longer than first ( Fig. 34C View FIG ). Operculum large, surmounting coxa, apically with 2 well-rounded lobes protruding to same height. Interior plate of vulva surmounting operculum ( Fig. 34D View FIG ).

SIMILAR SPECIES

The shape of posterior telopods is unique for described Malagasy Sphaerotheriida .

DESCRIPTION

Body measurements: males (2 specimens): length up to 3.0, width of thoracic shield up to 13.4, height of thoracic shield up to 7.8. Females (4 specimens): length up to 2.4, width up to 24., height up to 13.3.

Habitus: tergites shiny and with few hairs. At high magnification small isolate pores and a leather-like surface become visible.

Coloration: tergites splendid blackish ( Fig. 19B View FIG ). Head, antennae and legs dark olive-greenish.

Head: posterior margin of head towards collum with patch of small hairs.

Antennae: length of joints: 1<2<3>4= <, sixth joint longest, of cylindrical shape ( Fig. 3 A, B View FIG ), apically with one row of sensilla basiconica, on tip bearing a disc with 12-19 sensory cones ( Fig. 3 B View FIG ). First joint remarkably broader than the others, short and without groove ( Fig. 3 A View FIG ). Sclerotized teeth at base of joints 1-2, not reaching apical border ( Fig. 3 A View FIG ). First joint apically on one side with 1 or 2 rows of sensilla basiconica ( Fig. 3 A View FIG ).

Mandible: with rows of pectinate lamellae, number of teeth decreasing proximad ( Fig. 3 B View FIG ). Condylus with 2 steps near apical margin, proximal step strongly developed, apical step barely visible.

Gnathochilarium: ventral side with few bristles ( Fig. 3 A View FIG ). No sensory cones visible lateral of palpi ( Fig. 3 C View FIG ).Two different types of sensory uvulae on central pads: long, cylinder-shaped ones with single medial pit and more plain ones without pit.

Collum: anterior and posterior margin each with c. 1 long hairs arranged in a single row. Remaining parts of collum glabrous.

Thoracic shield: glabrous, but lateral extensions especially at margins with patch of long hairs.

Tergites: tips of paratergites posterior margin projecting posteriorly. Tergites smooth and with few, small isolated hairs,.

Endotergum: internal section with short spines and isolated bristles. One row of elliptical cuticular patterns, standing in a small distance towards one another between marginal ridge and internal area ( Fig. 37 View FIG ). External 2 (in rare exceptions three) rows of marginal bristles, placed closely to one another. Bristles slightly surmounting posterior end of tergite ( Fig. 37 View FIG ).

Anal shield: bell-shaped. In contrast to the almost glabrous and polished tergites with numerous hairs. Underside carrying 2 well-developed black locking carinae on both sides, anterior one small, posterior carina4 times longer than first, at posterior end slightly projecting towards anal shield margin ( Fig. 34C View FIG ). Locking carinae separated from each other by a distance equal to the length of shorter carina ( Fig. 34C View FIG ).

Legs: first tarsi with up to 4, second with up to

, third pair with -8 long ventral spines. First two tarsi with only weakly curved claws and without apical spine. Tarsi 3-21 with curved claws, 7-10 ventral spines and an apical spine. Ventral spines dispersed through whole inner margin of tarsus ( Fig. 34A View FIG ). In 9th leg, femur 1.8 and tarsi 4.8 times longer than wide ( Fig. 34A View FIG ).

Stigma-carrying plate: first stigma-carrying plate lobe short and stout, protruding up to apical edge of coxa 1. Lobe only weakly curved towards coxa, broad, stout tip only a little thinner than more basal parts ( Fig. 34B View FIG ).

Female sexual characters: subanal plate with a washboard, consisting of well-developed stridulation ribs, 1 or 2 on each side. Stridulation ribs symmetrical, sometimes non-continuous. Ribs long, ending shortly before posterior margin of plate ( Fig. 34E View FIG ). Vulva large, covering more than 4/ of coxa ( Fig. 34D View FIG ). Operculum surmounting coxa. Operculum medially notched with 2 rounded lateral tips, both protruding to same height ( Fig. 34D View FIG ). Inner plate extraordinary long and broad, surmounting operculum ( Fig. 34D View FIG ).

Male sexual characters: male gonopore large, covered with one sclerotized, undivided and rounded plate. Apical part of plate membranous. Gonopore covering 2/ of coxal height and more than 1/2 of coxal width ( Fig. 34F View FIG ). Anal shield bell-shaped and completely covered with numerous small hairs.

Anterior telopods: first joint with a stridulation harp and two stridulation ribs. Both ribs straight and of same length ( Fig. 34G View FIG ). Second joint on posterior side with single, lobe like, weakly curved process with rounded edges ( Fig. 34H, I View FIG ). Point of process protruding almost as high as third joint, towards third joint apically with sclerotized spots and basally with spine ( Fig. 34H View FIG ). Third joint almost as wide as process of second joint, of cylindrical shape with well-rounded apical margin. Juxtaposed to process of second joint with a cavity. Margin towards cavity with sclerotized teeth, numerous sclerotized spots and 3 small spines. Spines located basally, medially and the largest one apically close towards tip ( Fig. 34 View FIG G-I).

Posterior telopods: third joint strongly curved around the suspiciously excavated tip ( Fig. 34J, K View FIG ). Hollowed-out margin towards second joint with 1 large membranous lobe and up to 4 smaller, sclerotized spines, 3 of them located around tip, fourth one largest and located adjacent to the lobe ( Fig. 34J View FIG ). Third joint on posterior aspect with row of c. 1 crenulated teeth ( Fig. 34K View FIG ). Process of second joint slim and shorter than third joint, with strongly curved tip. Anterior side basally with 1 membranous lobe and 1 sclerotized spine, furthermore on inner margin around tip with numerous small, sclerotized spots juxtaposed to third joint. Third joint only basally with few isolated hairs, hairs absent on rest of surface ( Fig. 34J, K View FIG ). First and second joint almost glabrous, on both sides with some isolated hairs ( Fig. 34J View FIG ). Inner horns of syncoxite apically curved posteriorly.Tips sharp, whole horns covered with numerous small hairs.

INTRASPECIFIC VARIATION

The material contained too few specimens to evaluate the intraspecific variation. Among the material, no variation among the locking carinae and only a little variation among the sensory cones of antenna and ventral spines on the legs were observed. The smaller individuals, including one male specimen, had well-rounded anal shields.

DISTRIBUTION AND ECOLOGY

This species is only known from the montane rainforest at Andranomay ( Fig. 41 View FIG ). It is unclear if this species is endemic to this single forest, but it was not found in other samples. At least four other giant pill-millipede species were collected in Andranomay, all of them are undescribed.

CONSERVATION

Because the species is until now only known from the montane forest in Andranomay ( Fig. 41 View FIG ), its prospects of survival are directly connected with the survival of this specific habitat. Because of the fast ongoing destruction of the forest ecosystems on Madagascar, Z. piligerum may be in urgent threat of extinction.