Zoosphaerium priapus (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 : 30-34

publication ID	https://doi.org/ 10.5281/zenodo.5391729
persistent identifier	https://treatment.plazi.org/id/AA451447-2B15-FFF0-FECD-FEFEFE959A62
treatment provided by	Marcus
scientific name	Zoosphaerium priapus (de Saussure & Zehntner, 1897 )
status

Treatment

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

( Figs 14-1 View FIG )

Sphaerotherium priapus de Saussure & Zehntner, 1897 : pl. 4, figs - d; 1902: 1.

Zoosphaerium priapus View in CoL – Jeekel 1999: 14 (lists species name). — Enghoff 2003: 20 (lists species name).

TYPE MATERIAL. — ♀ lectotype (here designated) ( MNHN CB042).

TYPE LOCALITY. — Madagascar, Antananarivo, leg. Catat, 1890.

OTHER MATERIAL EXAMINED. — Forêt d’Orangea, 3. km 128° SE Remena, 12°1 ’32’’S, 49°22’29’’E, littoral forest, 90 m, pitfall trap, leg. Fisher, Griswold et al., 2 ♂♂, 12 ♀♀, 1 juv. ( FMMC 3911 ) GoogleMaps ; 1 ♀ ( FMMC 3922 ) GoogleMaps .

DIAGNOSIS. — Up to 30 mm long. Light brownish, posterior margin of tergites and anal shield laterally with black pattern. Surface of tergites smooth and glabrous. Anal shield well-rounded, with rough, leather-like surface, underside carries 2 locking carinae, both short, second even weaker and shorter than first, in some specimens completely absent ( Fig. 14C View FIG ). Antennomeres 1- with sclerotized teeth, apical joint with 1 -2 sensory cones. All antennal joints without groove ( Fig. 14A View FIG ). Legs short, covered with numerous long hairs ( Fig. 14B View FIG ). First 3 pair of legs without apical spine. Third joint of posterior telopods weakly curved, posterior side with up to 18 sclerotized teeth, two large, non-sclerotized lobes and c. 4 sclerotized spines ( Fig. 14K, L View FIG ). Second joint with broad and stout immovable process and basally with 1 large membranous lobe and a spine.Two stridulation ribs on each male harp and 2-4 on each side of female washboard ( Fig. 14E, G View FIG ). Operculum of vulva large, surmounting coxa, apically with 2 well-rounded lobes protruding to same height ( Fig. 14D View FIG ).

SIMILAR SPECIES

The short and hairy legs, the shape of female operculum and special surface of the anal shield separates Z. priapus easily from all other described Malagasy sphaerotheriids.

DESCRIPTION

Body measurements: males (2 specimens): length up to 17.9 (in literature: 2. mm, de Saussure &

Zehntner 1902), width of thoracic shield up to 8.8, height of thoracic shield up to 4.9. Females (13 specimens): length up to 30.2, width up to 14.1, height up to 8.0.

Habitus: body high, reaching its highest point at midbody tergites.Tergites smooth and glabrous, at high magnification, small isolate pores and a weak, leather-like surface becomes visible.

Coloration: tergites lightly brown, sometimes brown-reddish, through posterior body end with dark black coloration pattern, becoming much thicker towards tips of paratergites. Posterior end of anal shield dark. Head and collum with dark olive-green to blackish coloration. Antennae and legs olive-greenish. Preserved specimens loose their coloration pattern in alcohol. A nice drawing of the coloration pattern of Z. priapus is shown in de Saussure & Zehntner (1897: pl. 4).

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. 1 A, C View FIG ), apically with 1 row of sensilla basiconica, on tip bearing a disc with 1 -2 sensory cones ( Fig. 1 C View FIG ). Antenna conspicuously short, protruding up to labrum tooth. First joint remarkably broader than others, but short and without groove ( Fig. 1 A View FIG ). Sclerotized teeth at the base of joints 1-, reaching apical border only on first joint. First joint apically on one side with 1 row of sensilla basiconica ( Fig. 1 B View FIG ).

Mandible: with rows of pectinate lamellae, number of teeth decreasing proximad ( Fig. 1 D View FIG ). Condylus with single, strongly developed step near apical margin ( Fig. 1 D View FIG ).

Gnathochilarium: ventral side with numerous, long bristles ( Fig. 1 E View FIG ). Lateral of palpi 4 sensory cones, located together ( Fig. 1 A, C View FIG ). Depression on backside of palpi with some sensory cones ( Fig. 1 A View FIG ). Two different types of sensory uvulae on central pads: long, cylinder-shaped ones with 1 pit in their middle and more plain ones without pit ( Fig. 1 A, B View FIG ).

Epipharynx: with numerous spines, similar in shape to all known species of giant pill-millipedes ( Figs 1 D View FIG ).

Collum: anterior margin with 20-30 long hairs arranged in one row. Posterior margin and edges with 12-1 fine long hairs. Remaining part of collum glabrous.

Thoracic shield: with few, but long hairs in the concave lateral extension of thoracic shield, especially at margins.

Tergites: tips of posterior paratergite margins slightly projecting posteriorly. Tergites smooth and glabrous.

Endotergum: internal section with short spines and few, isolated bristles ( Fig. 1 E View FIG ). One row of small, circular cuticular patterns between marginal ridge and internal area ( Fig. 1 E View FIG ). Externally two, in some rare cases three rows of marginal bristles, placed closely to one another. Bristles long, surmounting tergite ( Fig. 1 E View FIG ).

Anal shield: extraordinary well-rounded, neither bell-shaped nor tapered. Reaching its hindmost point slightly above its lower side. In contrast to glabrous and smooth tergites with rough, leatherlike surface, particularly towards hindmost end. In male specimens covered with numerous small hairs. Underside carries 2 black locking carinae on both sides, anterior one small, but well-developed, posterior carina dot-like, in some specimens even completely absent ( Fig. 14C View FIG ). Locking carinae separated from each other by a distance equal to twice the length of shorter carina ( Fig. 14C View FIG ).

Legs: first tarsi with 2 or 3, second with 2-4 long ventral spines. Third tarsi with 3 or 4 long and two short ventral spines. First 3 (!) tarsi with only weakly curved claws and without apical spine. Tarsi 4-21 with curved claws, 8 or 9 ventral spines and an apical spine. Legs, especially the femur ( Fig. 14B View FIG ), short (femur 1.4 times longer than wide, in Z. arborealis is the femur twice longer than wide). Tarsi 3.2 times longer than wide (in Z. alluaudi 4.2, in Z. arborealis even. times longer than wide).

Stigma-carrying plate: first stigma-carrying plate lobe long, surmounting coxa 1, covered sparsely with hairs. Lobe almost straight and only weakly curved towards coxa ( Fig. 14A View FIG ).

Female sexual characters: subanal plate with a washboard, consisting of well-developed stridulation ribs, 2 up to 4 ribs on each side. Stridulation ribs symmetrical, strong and long, ending shortly before the posterior margin ( Fig. 14E View FIG ). Vulva large, covering more than 4/ of coxa ( Fig. 14D View FIG ). Operculum high, surmounting apical edge of coxa. Apical margin of operculum medially notched, with 2 rounded lateral tips, both tips protruding to same height ( Fig. 14D View FIG ). Inner plate protruding almost as high as operculum ( Fig. 14D View FIG ).

Male sexual characters: male gonopore small, covered with one large, sclerotized, undivided and rounded plate. Plate covered with few, isolated, long hairs. Apical part of plate membranous. Gonopore covering 1/3 of height and 3/ of width of coxa ( Fig. 14F View FIG ). Anal shield well-rounded, covered with field of small hairs around its hindmost point.

Anterior telopods: first joint with a stridulation harp and 2 stridulation ribs. Both ribs straight and of same length ( Fig. 14G View FIG ). Second joint on posterior side with lobe-like, weakly curved process with rounded edges ( Fig. 14I, J View FIG ). Point of process with sclerotized spots, reaching almost as high as third joint ( Fig. 14I View FIG ). Third joint with a cavity juxtaposed to second joint process. Apical margin of third joint well-rounded, laterally with a projection. Inner margin and lateral projection arched towards second joint. Internal margin towards cavity with numerous sclerotized spots and 4 small spines, three of them located closely towards tip ( Fig. 14H View FIG ). One additional short spine standing inside of cavity juxtaposed to second joint ( Fig. 14 View FIG G-J).

Posterior telopods: third joint weakly curved. Hollowed-out margin towards second joint with two non-sclerotized lobes and up to four smaller, sclerotized spines ( Fig. 14K View FIG ). In posterior view a row of c. 18 crenulated teeth ( Fig. 14L View FIG ). Immovable process as broad as third joint, with weakly curved tip. Anterior side basally with 1 membranous lobe, and 1 short sclerotized spine, furthermore whole inner margin covered with numerous small sclerotized spots juxtaposed to third joint. Third joint only basally with few isolated hairs, on rest of surface hairs absent. First and second joint on both sides with some isolated hairs ( Fig. 14K, L View FIG ).

INTRASPECIFIC VARIATION

Too few male specimens were among the material examined to evaluate if the males in this species are significantly smaller than females or not. Generally,

smaller individuals have better-developed second locking carinae on the anal shield and seem to have a fewer number of antennal cones on antennae (1 -20 in specimens <20 mm, 21- 2 in specimens> 22 mm). Furthermore, small females have a fewer number of stridulation ribs on the washboard. The number of tarsal spines and the shape of the anal shield are constant in all specimens.

DISTRIBUTION AND ECOLOGY

This species was until now only known from its first description with the locality “ Antananarivo ”. It remains unclear if the specimens were really collected in or around the capital of Madagascar or if they were just purchased there by Catat. The only reliable locality of this conspicuous coloured species is the littoral forest of Orangea in the far north part of the island ( Fig. 13). It is unclear if this species is endemic to this single forest or to the littoral forest ecosystem. The brown-blackish coloration pattern, the long hairs on the legs and particularly the short, broad legs suggest that Z. priapus lives inside the soil. No other giant pill-millipede species was collected in Orangea forest.

CONSERVATION

Because the species is until now only known from the littoral forest in Orangea, its prospects of survival are directly connected with the survival of this forest. Because of the fast ongoing destruction, especially of the littoral forest ecosystem (de Gouvenain & Srilander 2003), Z. priapus is possibly in an urgent threat of extinction.