Zoosphaerium bilobum, Wesener, 2009

Wesener, Thomas, 2009, Unexplored richness: discovery of 31 new species of Giant Pill-Millipedes endemic to Madagascar, with a special emphasis on microendemism (Diplopoda, Sphaerotheriida), Zootaxa 2097 (1), pp. 1-134 : 90-94

Zoosphaerium bilobum , new species

Derivatio nominis: bilobum , adjective, refers to the two triangular lobes on the posterior telopods (Fig. 61E).

Studied material: Holotype: 1 M (25.5 mm long), FMMC 5457 , Locus typicus: Madagascar: Province Toliara, Forêt de Vohibasia #3, 59km NE Sakaraha, 22°27.5'S, 44°50.5'E, 780 m, coll. S. Goodman, 10–16.i. 1996.

Distribution & Ecology: Only known from the subhumid forest Vohibasia in SW-Madagascar (Fig. 50).

This species occurs sympatrically with Z. album , n. sp..

FIGURE 061. Zoosphaerium bilobum n. sp., holotype, A: second left coxa with gonopore, posterior view; B: left half of anterior telopods, anterior view; C: last two podomeres of anterior telopod, lateral view; D: last three podomeres of anterior telopod, posterior view; E: posterior telopod, anterior view; F: posterior telopod, posterior view. Abbreviations: cav = cavity; Cx = coxa; Go = gonopore covered with plate; ml = membranous lobe; s-p = sclerotized spot; scl-t = sclerotized teeth; SR = stridulation ribs. Scale bars = 1 mm.

Diagnosis: Up to 25.5 mm long. Color brownish-green. Texture of tergites smooth, at high magnification leather-like texture becomes visible. Anal shield excavated, covered with numerous short hair. Disc of antenna with four apical cones (Fig. 62C), first antennomere with groove (Fig. 62A) and sensilla basiconica (Fig. 62B). First and fifth antennomere laterally with sensilla basiconica (Fig. 62A). Posterior telopods almost glabrous (Figs 61E, F). Movable finger broad, with well-rounded tip and two large lobes and three sclerotized spines (Fig. 61E), posterior side with circa 12 sclerotized teeth (Fig. 61F). Fixed finger long and wide, very weakly curved; basally with one small spine, distally at inner margin with numerous sclerotized spots (Fig. 61E). Fixed finger shorter than movable finger. One stridulation rib on each male harp (Fig. 61B). Anal shield with two locking carinae, first small, second more than 2.5 times longer than first. Endotergum with two rows of cuticular impressions (Fig. 63F). Marginal bristles standing in two rows, numerous of them strongly extending beyond tergite margin (Fig. 63F).

Similar species: Z. bilobum , n. sp. features a unique combination of characters, like four antennal apical cones and one stridulation rib on the male harp. Z. bilobum , n. sp. posterior telopods are very similar to those of Z. isalo , n. sp. but can be distinguished from the latter by the very different endotergum and different shaped anterior telopods.

Description: Body length: Holotype male: length 26 mm, width of thoracic shield up to 14.1 mm, height of thoracic shield up to 7.9 mm.

Coloration: Faded in alcohol. Light to darkish brown. Head, antennae and legs green.

Head: Eyes with>75 ocelli.

Antennae: Length of antennomeres: 1>2=3<4=5<6 (Fig. 62A), sixth antennomere longest, bearing disc with four sensory cones (Fig. 62C). First antennomere remarkably broader than others, short, with groove and 1 or 2 rows of sensilla basiconica (Fig. 62B). Sclerotized teeth at base of antennomeres 1–5 (Fig. 62A).

Mouthparts not dissected.

Collum: Margins and remaining part of collum with few, isolated hair.

Thoracic shield: Surface structured like other tergites.

Tergites: Paratergites not projecting.

Endotergum: Inner area with thin conical spines and long hair. Two rows of cuticular impressions present, regularly distributed (Fig. 63F). Inner row consisting of large, elliptical impressions, outer row consisting out of smaller impressions. Two dense rows of marginal bristles, strongly protruding above tergite (Fig. 63F).

Anal shield: Excavated at hindmost point and covered with numerous short hairs. Underside carries two well-developed black locking carinae, anterior one small, but well developed. Posterior carina more than 2.5 times longer than anterior one.

Legs: Tarsi of first pair of legs with six up to seven, second with eight or nine, third pair with ten ventral spines. First two leg pairs with only weakly curved claws and without apical spine. Tarsi of legs 3–21 with curved claws, 11 or 12 ventral spines and one apical spine. In 9th leg femur 1.9 times, tarsi 4.6 times longer than wide.

FIGURE 062. Zoosphaerium bilobum n. sp., holotype, SEM, antenna A: lateral view; B: first antennomere with sensilla basiconica; C: apical view on sixth antennomere with disc. Abbreviation: sb = sensilla basiconica.

Stigmatic plates: First lobe triangular with well-rounded tip.

Female unknown

Male sexual characters: Male gonopore covered by large, sclerotized, undivided and rounded plate. Apical part of plate membranous (Fig. 62A).

FIGURE 063. SEM, endoterga of midbody tergites, A: Zoosphaerium amabile n. sp.; B: Z. trichordum n. sp.; C: Z. smaragdinum n. sp.; D: Z. ambrense n. sp.; E: Z. isalo n. sp.; F: Z. bilobum n. sp. Abbreviations: ci = cuticular impressions; IA = inner area; mb = marginal bristles; mr = marginal ridge.

Anterior telopods (Figs 62B–D): Syncoxite on both sides with only very few, isolated hairs. Harp with single stridulation rib, straight and well-developed. Second podomere process lobe-like and little curved with rounded edges, reaching almost as high as third podomere, apically with sclerotized spots. Third podomere long, cavity mesally with numerous sclerotized spots, more basally with one spine; three additional spines and one sclerotized teeth located close to tip.

Posterior telopods (Figs 62E, F): Movable finger of chela weakly curved, apically slightly tapering. Hollowed-out inner margin with three sclerotized spines and two large membranous lobes, posterior aspect with circa 12 sclerotized teeth. Fixed finger wide, but shorter and more slender than movable finger. Tip of fixed finger weakly curved; anterior side basally with one short sclerotized spine, on tip with numerous sclerotized spots. Only posterior side of second podomere covered with few hairs, remaining part of posterior telopods glabrous. Inner horns of syncoxite curved. Tips sharp, whole horns covered with numerous short hairs.

FIGURE 064. Zoosphaerium tampolo n. sp., A, B, D–G holotype, C female paratype A: first left coxa and prefemur with first stigmatic plate, anterior view, B: first stigmatic plate, posterior view; C: second left coxa with vulva, posterior view; D: left half of anterior telopods, anterior view; E: last two podomeres of anterior telopod, lateral view; F: posterior telopod, anterior view; G: posterior telopod, posterior view. Abbreviations: cav = cavity; cr-t = crenulated teeth; Cx = coxa; EP = external plate of vulva; IP = mesal plate of vulva; O = operculum; Pre = prefemur; s-p = sclerotized spot; scl-t = sclerotized teeth; SR = stridulation rib; St = stigmatic plate. Scale bars = 1 mm.