Iguazus robustus, Bouzan & Pena-Barbosa & Brescovit, 2017

Bouzan, Rodrigo S., Pena-Barbosa, João Paulo P. & Brescovit, Antonio D., 2017, Two new Brazilian species of Chelodesmidae of the genera Iguazus and Tessarithys (Diplopoda: Polydesmida), Zoologia (e 19986) 34, pp. 1-8 : 2-4

Iguazus robustus sp. nov.

http://zoobank.org/ CE310199-8C38-444C-9A0D-644298CDBED5

Figs 1–3, 7–12, 19–21, 28

Diagnosis. Males of this species differ from those of other species of the genus by having a constriction in the zone of the gonopodal acropodite tip ( Fig. 1, arrow) and an extra branch at the tip of the acropodite.

Description. Female: Unknown. Male (Holotype, IBSP 4397): Head reddish with a yellow labrum, Tömösvary organ suboval in shape. Antennae reddish brown, terminal antennomere with invaginations between the four apical sense cones. Body reddish brown and paranota tip yellow, gradually losing the brown color towards the posterior body rings, reddish brown color in the mid-body ring restricted to the anterior and posterior edge and yellow filling the remaining portion ( Figs 19–21). Body rings: tegument smooth; alignment of paranota ventrally curved; paranota with posterior edges acutely produced from body ring 5; ozopore centrally situated on body ring 5; and posteriorly situated on the other body rings; ozopore arrangement at the edge of paranota: 5, 7, 9, 10, 12, 13, 15-19 (following the standard polydesmid pore formula). Penultimate body ring with reduced paranota ( Fig. 12, arrows). Stigma oval and elongated. Coxae of leg pair 2 nd with rectangular shaped genital papilla ( Fig. 7, arrows). Sternite of body ring 5 with a pair of elongated projections ( Fig. 8). Sternite of body ring 8 presenting two pairs of pointed projections in the zone anterior to the coxae ( Fig. 9, arrows). Gonopod aperture on seventh body ring: elliptical, posterior edge without folds. Legs whitish yellow, with rounded ventro-apical process on the prefemur and with an apical-ventral membranous projection on the tibia ( Figs 10–11), leg modifications are present in all pairs except the last. Telson yellowish with dark brown edges. Total length: 39. Collum 2.08 long, 5.46 wide. Antennomere length: 0.26; 1.14; 1.23; 1.15; 1.27; 1.00; 0.21. Gonopod aperture 1.66 long, 2.56 wide. Telson 0.85 long. Gonopods ( Figs 1–3): gonopod coxae equivalent to about half the length of the telopodite and prominent in ectal view ( Fig. 3). Coxae with two bristles in the distal dorsal side. Spiniform projection present. Cannula ( Fig. 1): hook-shaped. Prefemoral region ventrally developed and short, 1/3 the size of telopodite. In ectal view, presence of a conspicuous groove near the beginning of the acropodite ( Fig. 3, arrow). Prefemoral process (PfP) long, massive, blade-like. In the middle portion, the prefemoral process divides into three different projections: the first projection, mesal view, sickle-shape ( Figs 1–3, a); the mid-projection, the largest among them, boat-shaped ( Figs 1–3, b); the last is the spine-shaped lower projection ( Figs 1–3, c). Acropodite (A) elongated and slender, carrying the seminal groove; acropodite is unbranched and sinuously-curved ( Figs 1–3); its distal portion, mesal view, displays a constriction, that resembles a cingulum where a moveable branch is attached, that results in a pointed tip and in a blade which seems to have the function of protecting this acute blade on the lateral side, thus the tip of acropodite is constituted for two branches ( Figs 1, 3).

Type material. Male holotype from Parque Estadual Pedra da Boca, Araruna (6°45’95”S, 35°67’78”W, 228 m), Paraíba, Brazil, 01-02.VI. 2012, I.L.F. Magalhães & J.L. Chavari col., deposited in IBSP 4397 .

Distribution. Known only from the type locality ( Fig. 28).

Etymology. The species epithet, robustus , is a reference to the massive prefemoral process and derives from the Latin word “robustus ”, “robusta”.