Bioacoustics of Zoosphaerium xerophilum

Description: Anal shield shape : Top well rounded, bottom sharply tapering downward. From apical view, shield looks slightly but sharply pointed posteriorly like bottom half of a hazelnut. Female sexual characters : Subanal plate with washboard possessing up to 5 stridulation ribs on each half, some long, some shorter. Vulva large, covering more than 3/4 of coxa ( Fig. 18 ). Operculum large, reaching past apical edge of coxa, with indent at apex halving it into two small same-sized mounds. Meso-apical region of operculum shallowly indented. Mesal plate long and broad, protruding to 0.5 of operculum height, but not past apical edge of coxa. Material examined: MADAGASCAR : Antsiranana Prov. : 1^( FMNH-INS 55897 ) Forêt d’Ambre , tropical dry forest, J. Köhler et al. , iii.2008 .

Diagnosis : Up to 38 mm long. Coloration light brown with darker posterior margins, appendages green. Texture of tergites smooth and glabrous. Antenna without groove (Fig. 27B), disc with>45 apical cones (Fig. 27C). Movable finger of posterior telopods broad, weakly curved, longer than fixed finger, with two large, non-sclerotized lobes and 3–5 thin spines (Fig. 26G), on posterior side with circa 28 sclerotized teeth (Fig. 26H). Fixed finger broad, basally with single, large membranous lobe and small spine (Fig. 26G). Two stridulation ribs on each male harp (Fig. 26D). Anal shield with two small locking carinae of equal length. Female unknown. Similar species : The species is distinct from all other members of this group by the special-shaped telopods and the presence of two small locking carinae on the anal shield.

Description : Body length : Males ( 3 specimens ): length up to 38 mm , width of thoracic shield up to 20.3 mm , height of thoracic shield up to 11.4 mm . Coloration : Faded during five years in alcohol. Tergites light-brown, posterior third dark brown. Head and collum also brown, ocelli, antennae and legs green. Head : Eyes with>75 ocelli. Antennae : Length of antennomeres: 1>2<3>4<5<<6 (Fig. 27A), sixth antennomere bearing disc with>45 apical cones (Fig. 27C). First antennomere short and cylindrical, without groove, apically on one side with 1 or 2 rows of sensilla basiconica (Fig. 27B). Sclerotized teeth present at base of antennomeres 1–5 (Fig. 27A). Mandible : Thin, five rows of pectinate lamellae, number of teeth declining apically to proximally. Condylus with single, strongly developed step near apical margin. FIGURE 026 . Zoosphaerium xerophilum n. sp. , male holotype , A : 9th left leg, posterior view; B : first left coxa and prefemur with first stigmatic plate, posterior view; C : left second coxa with gonopore, posterior view; D: right side of anterior telopod, anterior view; C : last two podomeres of anterior telopod, posterior view; D : anterior telopod, last two podomeres, lateral view; E : posterior telopod, anterior view; F : posterior telopod, chela, posterior view. Abbreviations: cav = cavity; cr-t = crenulated teeth; Cx = coxa; ml = membranous lobe; Pre = prefemur; rdg = femur ridge; s-p = sclerotized spot; SR = stridulation ribs; St = stigmatic plate. Scale bars = 1 mm . FIGURE 027 . Zoosphaerium xerophilum n. sp. , SEM, paratype , A: antenna, lateral view; B : antenna, first antennomere with sensilla basiconica (arrow); C : antenna, apical view on disc; D : gnathochilarium, right inner palpus with rudimentary lateral palpus. Abbreviations: iP = inner palpus; rlp = rudimentary lateral palpus; sb = sensilla basiconica ; v = depression on posterior side of palpus. Gnathochilarium : Lateral of palpi 3 or 4 sensory cones, located together (Fig. 27D). Depression on posterior side of palpi with numerous sensory cones (Fig. 27D). Collum : Median part of collum glabrous. Thoracic shield : Generally, concave lateral extensions not deeply invaginated. Tergites: Smooth and glabrous. Paratergites slightly projecting posteriorly. Endotergum : Inner section with thin spines and few, isolated bristles (Fig. 35B). Between marginal ridge and inner area single row of large, elliptical cuticular impressions within regular distance to one another (Fig. 35B). Externally three rows of marginal bristles, inserting closely to one another. Bristles extending beyond tergite (Fig. 35B). Anal shield : Anal shield slightly excavated at hindmost point. Ventral side carries two black locking carinae, both carinae of equal size. Legs : Tarsi of first pair of legs with five or six, second with up to seven and third with seven to nine ventral spines. First two leg pairs with only weakly curved claws and without apical spine. Tarsi of legs 3–21 with curved claws, 12–13 ventral spines and one apical spine. Femur 2.0, tarsus 4.7 times longer than wide (Fig. 26A). Stigmatic plate : First lobe broad and well-rounded (Fig. 26B). Female unknown Male sexual characters : Male gonopore small, covered by sclerotized, undivided and rounded plate. Apical part of plate membranous (Fig. 26C). Anterior telopods (Figs 26D–F): First podomere with harp and two stridulation ribs. Both ribs straight, mesal rib longer but thinner than lateral rib. Second podomere process lobe-like and little curved with rounded edges, reaching almost to half of third podomere height, with sclerotized spots. Third podomere cavity mesally with sclerotized spots and 4 or 5 small spines, three of them located closely towards tip. Tip with one triangular, sclerotized spot. Posterior telopods (Figs 26G, H): Movable finger of chela long and slightly curved; hollowed-out inner margin with two non-sclerotized lobes and 5 or 6 smaller, sclerotized spines, posterior aspect with circa 28 crenulated teeth. Fixed finger only 2/3 as wide as movable finger, also significantly shorter, with almost straight tip. Finger with single membranous lobe, on inner margin covered with numerous sclerotized. First podomere on both sides almost glabrous, second podomere on both sides covered with numerous hair, leaving out the fixed finger. Movable finger only basally with numerous hair.