Rupidesmus aclys, Bouzan & Iniesta & Brescovit, 2018

Bouzan, Rodrigo Salvador, Iniesta, Luiz Felipe M. & Brescovit, Antonio Domingos, 2018, A review of the millipede genus Rupidesmus Schubart, 1952 (Polydesmida: Chelodesmidae), Zootaxa 4434 (3), pp. 589-599 : 593

Rupidesmus aclys new species

Figures 2D–F , 3D–F , 6

Type material. Male holotype from Fazenda Izabela Hendri , Sabará (43°49'34.29"W, 19°53'4.26"S), Minas Gerais, Brazil, 06.XI.2008, J.P.P. Pena-Barbosa coll., IBSP 2890 .

Diagnosis. Adults males of Rupidesmus aclys n. sp. differ from R. ruber based on combination of gonopodal characteristics: Prefemoral process directed parallel to acropodital branch ( Fig. 3D ). Prostatic groove softened and S-shaped along the acropodite, ending upon an elongated prostatic apex ( Fig. 3D ). Indention restricted to posterior margin. Presence of an acute acropodital process in ectal view ( Fig. 3F ).

Description. Male (Holotype, IBSP 2890). Coloration (long-preserved in 70% ethanol): Head reddish brown with a light brown labrum. Antennae light reddish brown with seventh antennomere yellow. Body reddish brown and paranota tip with the same color as the body ( Figs 2D–F ). Body rings: cuticle smooth; paranota with posterior edges sub-rectangular ( Fig. 2E ); ozopore posteriorly situated on paranota. Stigma oval. Sternite of body ring 5 with a pair of elongated projections ( Fig. 6D ). Pair of legs on body ring 3 with coxae possessing a rectangular-shaped genital papilla, and pairs of legs on body rings 5 to 17 with two pairs of rounded projections between coxae ( Fig. 6F , arrows). Gonopod aperture on seventh body ring ( Fig. 6E ) elliptical, posterior edge without folds. Legs whitish red, with rounded ventro-apical process on the prefemur and an acute apical-ventral membranous projection on the tibia ( Figs 6A–C ), leg modifications present in all pairs except the last. Telson with the same color as the body. Total length: 72.5 (Fragmented). Collum 3.07 long, 8.11 wide. Antennomere lengths (1>7): 0.94; 1.93; 1.72; 1.71; 1.83; 1.75; 0.47. Gonopod aperture 1.99 long, 3.05 wide. Telson 2.06 long.

Gonopods ( Figs 3D–F ): coxae equivalent to about half the length of the telopodite and prominent in ectal view ( Fig. 3F ). Coxae with two setae on the distal dorsal side and with four setae on distal ventral side. Presence of a spiniform process hidden by the coxa in mesal view (SP; Fig. 3E ). Cannula: hook-shaped. Prostatic groove softened and S-shaped. Prefemoral region ventrally developed and short, 1/4 length of telopodite. Prefemoral process small and directed parallel to acropodital branch (PfP; Fig. 3D ). Acropodite elongated and robust (A; Fig. 3D ); conspicuous indentation restricted to posterior margin of the telopodite ( Fig. 3D , arrow). Acropodite apex, in ectal view, with an acute acropodital process (AP; Figs 3D, F ). The posterior edge of apical region ends in a pointed tip ( Figs 3D–F ).

Female. Unknown.

Distribution. The species is known only from the type locality.

Etymology. The species epithet is a noun in apposition, from the Latin word aclys meaning “short lance”. The name refers to the shape of the small prefemoral process on the gonopod.

Figures

FIGURE 2. Dorsal views of anterior (A, D), midbody (B, E) and posterior (C, F) body rings of Rupidesmus ruber (holotype, MZSP 996) (A–C) and Rupidesmus aclys n. sp. (holotype, IBSP 2890) (D–F). Scale bar: 2 mm.

FIGURE 3. Rupidesmus ruber (holotype, MZSP 996), left gonopod. A, mesal view; B, lateroventral view; C, ectal view. Rupidesmus aclys n. sp. (IBSP 2890), left gonopod. D, mesal view; E, lateroventral view; F, ectal view. Scale bars: 1 mm. Abbreviations: AP, acropodital process; PfP, prefemoral process; PG, prostatic groove; SP, spiniform projection on gonopod coxae. Arrows refer to the indentation at the posterior margin of the acropodite.

FIGURE 6. Rupidesmus aclys n. sp. (holotype, IBSP 2890). A, leg (8 th leg pair) in lateral view; B, detail of prefemur, ventroapical process; C, detail of tibia, apico-ventral membranous projection; D, sternite of body ring 5 in dorsal view; E, aperture of gonopod; F, sternite on body ring 8. The arrows point to the pairs of projections of the sternites on body ring 8. Scales bars: 1 mm. Abbreviations: VaP, ventro-apical process; MP, membranous process.