Tessarithys exacuminatus, 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 : 4-6

Tessarithys exacuminatus sp. nov.

http://zoobank.org/ B511E597-DFD1-45C0-AAC9-F95D21001B5A

Figs 4–6, 13–18, 22–27, 29

Diagnosis. Males of this species differ from those of other species of the genus by the large and ascending subterminal dorsal branch of the prefemoral process of the gonopod ( Fig. 4).

Description. Female: Unknown. Male (Holotype, IBSP 4431): Head dark reddish with a yellow labrum, Tömösváry organ suboval in shape. Antennae reddish brown, terminal antennomere with invaginations between the four apical sense cones. Body purple, coloration of paranota tip differing from body ring 5, reddish yellow ( Figs 22–24). Body rings: tegument slightly rough. Alignment of paranota: ventrally curved ( Fig. 18); paranota with posterior edges acutely produced from body ring 5; ozopore centrally situated on body ring 5, and posteriorly situated on the others; 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. Stigma oval and elongated. Coxae of 2 nd leg pair with rectangular shaped genital papilla ( Fig. 13, arrows). Sternite of body ring 4 with a pair of small rounded projections ( Fig. 13). Sternite of body ring 5 with two pairs of elongated projections ( Fig. 14). Sternite from body ring 8 presenting two pairs of pointed projections in the zone anterior to the coxae ( Fig. 15, arrows). Gonopod aperture on seventh body ring: transversal oval, posterior edge without folds. Legs reddish, with a membranous apical-ventral projection on the tibia ( Fig. 16–17); leg modifications are present in all pairs except on the last. Telson purple. Total length: 42.5 (Fragmented). Collum 2.03 long, 5.50 wide. Antennomere length: 0.41; 1.17; 1.28; 1.04; 1.23; 1.01; 0.20. Gonopod aperture 1.40 long, 2.77 wide. Telson 1.58 long.

Gonopods ( Figs 4–6): gonopod coxae equivalent to about half the length of the telopodite and prominent in ectal view ( Fig. 6). Coxae with two bristles in the distal dorsal side. Spiniform projection absent. Cannula ( Fig. 4): hook-shaped. Prefemoral region short, ventrally developed, 1/3 the size of telopodite. Presence of a conspicuous groove near the first portion of the acropodite, in the ectal view ( Fig. 6, arrow). Prefemoral process (PfP) long, parallel to the acropodite (A); displays a long and acuminated subterminal dorsal branch on the middle portion ( Figs 4–6, X). The final portion of the prefemoral process passes on the back of the acropodite, forming a distinct protection on the lateral side, with two blades forking in the terminal portion ( Fig. 4). Acropodite (A) long and slender, with solenomere and one additional branch ( Fig. 4). Spermatic groove mostly visible in mesal view except at the base of the acropodite where it diverts to the ectal side.

Variation. The body of the paratype (IBSP 4434) shows reddish brown coloration, with the edges of the paranota whitish yellow, tegument smooth and with a median band present, weakly developed ( Figs 25–27).

Type material. Holotype: one male ( IBSP 4431 ) from Reserva Particular do Patrimônio Natural Pedra do Cachorro (8°14’22.9”S, 36°11’13.7”W), São Caetano, Pernambuco, Brazil, 26.V.2012, I.L.F. Magalhães & J.L. Chavari coll. Paratypes: one male ( IBSP 4434 ) same data as holotype and one male ( IBSP 4634 ) from Unidade de Conservação Monumento Natural Grota do Angico , Poço Redondo (9°80’65”S, 37°68’36”W), Sergipe, Brazil. I. 2013, R. G. Faria coll.

Distribution. Known only from the type locality ( Fig. 29). Etymology. In reference to the acuminated subterminal dorsal branch, labelled “X” in figs 7-9 in Hoffman 1990.