Zoosphaerium blandum (de Saussure & Zehntner, 1902 )

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 : 3-8

publication ID	https://doi.org/ 10.5281/zenodo.5391729
persistent identifier	https://treatment.plazi.org/id/AA451447-2B36-FFD2-FF35-FCF9FBBA9CAF
treatment provided by	Marcus
scientific name	Zoosphaerium blandum (de Saussure & Zehntner, 1902 )
status

Treatment

Zoosphaerium blandum (de Saussure & Zehntner, 1902) View in CoL

( Figs 38-40 View FIG View FIG View FIG )

Sphaerotherium blandum de Saussure & Zehntner, 1902: 3 , pl. 1, figs 9-9b, figs 10-10c.

Sphaerotherium stridulator de Saussure & Zehntner, 1902 :, pl. 1, figs - e n. syn.

Sphaerotherium (Globotherium) blandum – Demange 19 9: 48, figs 4-7.

Zoosphaerium blandum View in CoL – Jeekel 1999: 12 (lists species name). — Enghoff 2003: 20 (lists species name).

TYPE MATERIAL. — Zoosphaerium blandum : coll. C. Alluaud, 1901, ♂ holotype ( MNHN CB011).

Sphaerotherium stridulator : coll. C. Alluaud, 1901, ♂ holotype ( MNHN CB04).

TYPE LOCALITY. — Zoosphaerium blandum and Sphaerotherium stridulator : Madagascar, col de Sakavalana (possibly Sakavalana mine), 20°44’48”S, 4 °4’30”E.

OTHER MATERIAL EXAMINED. — Madagascar. Andrahomana, coll. C. Alluaud, VIII-XI.1900, 1 immature ♂ ( MNHN CB011) (maybe Province Toliara, 2 °10’ 0”S, 4 °40’0”E, 89 m). — Sud-Ouest, Tulear, coll. I. Bigot, VI.19, 1 ♂ ( MNHN CB011). — 7. km ENE Hazofotsy (Réserve naturelle intégrale d’Andohahela camp #), 24°49.0’S, 4 °3. ’E, 120 m, leg. S. Goodman, 7-1.XII.199, 1 ♂ ( FMMC 372).

DIAGNOSIS. — Up to 23 mm long. Colour faded in alcohol. Surface of tergites smooth and glabrous. Anal shield weakly rounded, with relatively steep slope.Antennomeres 1-3 with sclerotized teeth ( Fig. 39A View FIG ). Apical joint with 4 sensory cones ( Fig.39A View FIG ). First antennal joint with groove ( Fig. 39A View FIG ). Third joint of posterior telopods of abnormal shape, posterior side with up to 1 sclerotized knobs, a single large lobe and up to sclerotized spines ( Fig. 38H View FIG ). Second joint immovable digit broad and strongly curved towards third joint, basally sometimes with 1 large membranous lobe and a spine ( Fig. 38G, I, J View FIG ). Two stridulation ribs on each male harp ( Fig. 38D View FIG ). Anal shield with 2 locking carinae of variable length, in some specimens are the posterior or even both carinae completely absent. Female unknown.

SIMILAR SPECIES

The unusual shape of the chela of posterior telopods in combination with the presence of two stridulation ribs on the harp identifies Z. blandum unambiguously.

DESCRIPTION

Body measurements (males, specimens): length up to 22.8, width of thoracic shield up to 10.7, height of thoracic shield up to.8.

Habitus: general appearance elongated.

Coloration: tergite coloration in alcohol faded, with mix of brown and greenish. The relatively fresh FMNH specimen shows a much darker coloration on posterior half of tergites. Head, collum, antennae and tips of legs greenish.

Head: posterior margin of head towards the collum without patch of small hairs.

Antennae: length of joints: 1<2>3=4= <, sixth joint longest, of cylindrical shape ( Fig. 39A View FIG ), apically with 1 row of sensilla basiconica, on tip bearing a disc with 4 () sensory cones ( Fig. 39A View FIG ). First joint remarkably broader than the others, short and with groove ( Fig. 39A View FIG ). Sclerotized teeth at base of joints 1-3, reaching apical border only on first joint ( Fig. 39A View FIG ). First joint apically on one side with 1 or 2 rows of sensilla basiconica ( Fig. 39B View FIG ).

Mandible: with rows of pectinate lamellae; number of teeth decreasing proximad ( Fig. 40B View FIG ). Condylus with 2 strongly developed steps at apical and inner margin, both steps of same strength ( Fig. 40B View FIG ).

Gnathochilarium: ventral side with some bristles ( Fig. 39C View FIG ). No sensory cones detectable lateral of palpi ( Figs 40A View FIG ). Sensory uvulae on central pads not clearly visible ( Fig. 40A View FIG ).

Collum: all hairs standing in pits. Anterior margin with c. 2 long hairs, posterior margin with only c. 1 long hairs. Remaining part of collum glabrous.

Thoracic shield: surface similar to those of tergites. Extensions shallow.

Tergites: tips of posterior paratergite margins not (!) projecting posteriorly. Tergites smooth and glabrous, at high magnification (> 40 ×) a weak leather-like surface becomes visible.

Endotergum: internal section with numerous slim, long spines and bristles ( Fig. 4 A View FIG ). Two rows of cuticular patterns, anteriorly large grooves, separated from one another, posteriorly small circular spots in touch with the ridge, located close to one another ( Fig. 4 A View FIG ). Externally a single row of marginal bristles. Bristles long, surmounting posterior end of tergite ( Fig. 4 A View FIG ).

Anal shield: weakly rounded, not bell-shaped but weakly tapered with steeper slope. Reaching its hindmost point on a small process of its lower side. In contrast to smooth tergites covered with numerous small hairs. Hairs located only on slope, especially toward its hindmost end. Underside carrying a variable number of locking carinae (see intraspecific variation). A distinct suture between both carinae, representing border of 13th tergite fused to anal shield.

Legs: first tarsi with 2-4, second with 3- long ventral spines. First 2 tarsi with only weakly curved claws and without apical spine. Tarsi 3-21 with curved claws, 8-12 ventral spines and an apical spine ( Fig. 38B View FIG ). Femur 1. times, tarsi 3. times longer than wide. Femora with crenulated ridge ( Fig. 38B View FIG ).

Stigma-carrying plate: first stigma-carrying plate lobe long, surmounting coxa 1. Plate covered sparsely with hairs, particularly around apical margin. Lobe almost straight, only weakly curved towards coxa, ending broad and blunt ( Fig. 38A View FIG ).

Female unknown.

Male sexual characters: male gonopore small, covered with single, large, sclerotized, undivided and rounded plate. Apical part of plate membranous. Gonopore covering 1/3 of height and 1/2 of coxal width ( Fig. 38C View FIG ). Anal shield well-rounded, covered with field of small hairs around hindmost point.

Anterior telopods: first joint with a stridulation harp and 2 stridulation ribs. Both ribs straight, lateral one much longer and better developed than internal rib ( Fig. 38D View FIG ). Second joint on posterior side with lobe like, weakly curved process with rounded edges ( Fig. 38E, F View FIG ). Point of process protruding up to half of third joint height, towards third joint with sclerotized spots ( Fig. 38F View FIG ). Apical margin of third joint well-rounded. Third joint with a cavity juxtaposed to second joint. Internal margin towards cavity with numerous sclerotized spots and a single small spine located closely towards tip. One additional short spine arising inside of cavity juxtaposed to second joints process ( Fig. 38E, F View FIG ). Syncoxite on both sides without hair ( Fig. 38D View FIG ). Only lateral borders of first joint sparsely covered with hair.

Posterior telopods: third joint curved and especially at inner margin irregularly rounded. Hollowed-out margin towards second joint with single large lobe and up to five smaller, sclerotized spines ( Fig. 38G, I, J View FIG ). Third joint on posterior aspect with one row of c. 1 crenulated teeth ( Fig. 38H View FIG ). Process of second joint as wide as third joint, with strongly arched tip. Anterior side basally with single membranous lobe and sclerotized spine (can be absent in some specimens), furthermore on whole inner margin around the tip with small, sclerotized spots juxtaposed to third joint. Second and third covered on both sides with long hairs, tips of both only laterally with isolated hairs ( Figs 38 View FIG G-J). Inner horns broad, with pointed tip arched backwards and covered with small hairs.

INTRASPECIFIC VARIATION

The male specimens differ a lot in some characters, which seem to be stable in other giant pill-millipede species (Wesener & Sierwald 200 a). Even specimens from the same locality (the types of

Z. blandum and Z. stridulator ) show variation in the development of the closing ledges on the anal shield. Some specimens show no carinae, others just 1, the specimen from Andohahela, 1 weak and 1 small dot-like posterior carina, and the type of Z. stridulator has 1 small and 1 long closing carinae. There is also variation in the number of spines and lobes on the chelae of posterior telopods. More material is necessary to evaluate the intraspecific variation of this species. Possibly genetic studies may show if Z. blandum includes cryptic species, or if the large amount of intraspecific variation is the effect of a hybridization process.

DISTRIBUTION AND ECOLOGY

This species shows a distribution around the dry forest in the southern part of Madagascar ( Fig. 41 View FIG ). In two of four localities it was found together with Z. libidinosum .

CONSERVATION

Because of the wide distribution in one of the least anthropogenically-affected Malagasy ecoregions ( Fig. 41 View FIG ), this species seems not to be under a threat of extinction.

REMARKS

In the original description of Sphaerotherium stridulator, de Saussure & Zehntner (1902) already mentioned that this species is closely related to Z. blandum , which has even the same type locality. Observation of the type material at the MNHN revealed that the original description by de Saussure & Zehntner (1902) had one eminent mistake: the drawing of anterior telopods shows and also the description text states that S. stridulator has 3 stridulation ribs, which would be a unique feature in the genus Zoosphaerium . Nevertheless, the studied holotype of S.stridulator has just 2 stridulation ribs, without any trace of a third one. Also the general appearance, shape of anal shield and number of sensory cones on the antennae, is the same in both type specimens. With these facts it is proposed to synonymize Sphaerotherium stridulator de Saussure & Zehntner, 1902 with Zoosphaerium blandum (de Saussure & Zehntner, 1897) .