Theratta, Anilkumar & Wesener & Moritz, 2022

Anilkumar, Pooja Avinipully, Wesener, Thomas & Moritz, Leif, 2022, First record of the order Polyzoniida from the Indian subcontinent with an integrative description of a new genus (Diplopoda, Colobognatha, Siphonotidae), Zootaxa 5182 (5), pp. 401-428 : 406

Genus Theratta n. gen. Anilkumar, Wesener & Moritz

Type species: Theratta mannavan n. sp. Anilkumar, Wesener & Moritz

Other species included: Theratta eravikulam n. sp. and Theratta shola n. sp.

Diagnosis. Habitus, size and coloration of Theratta species resemble those of the widespread introduced tramp species Rhinotus purpureus . Distinguished from the three other genera of the tribe Rhinotini by the bifurcation of the podomere II of anterior gonopod into a mesal process on the posterior side, with a furrow between the mesal process and the main part of the podomere II ( Figs 5D–F ); modification of the anterior side of anterior gonopod into a lamellar process ( Fig. 6C ); absence of conical elevations on the sternite of the posterior gonopod ( Figs 6I, J ), as found in the genera Rhinotus (see Wesener 2014) and Siphonoconus (see Attems 1931). Eyes consisting of a single pair of ommatidia ( Fig. 3A ); head with a pair of macrosetae anterior to the ommatidia ( Figs 2B , 3A ); tarsal claw with a thin paronychium extending beyond the claw, curved and bulged distally ( Fig. 4F ); tergites with groove-like striae; anterior margin of metazonites with a distinct row of striae ( Fig. 4A ); lateral margin of the pleurite covered with setae ( Fig. 3H ).

Etymology. Genus epithet, Theratta , noun, feminine. Millipedes are called ‘ Theratta ’ in Malayalam, the language spoken in the Indian province (Kerala) of the type species.

Figures

FIGURE 2. Theratta mannavan n. sp.. A, B: M paratype (ZFMK-MYR 9482A1). A: Habitus. B: Head, lateral view. C, D: Habitats, Mannavan Shola, Annamudi Shola National Park, Kerala, India. Abbreviations: an = antenna; co = collum; gp = gonopod; ms = macroseta; om = ommatidia.

FIGURE 3. Theratta mannavan n. sp., SEM. A, D, E: M paratype (ZFMK-MYR 9483A). B, C, F, G: M holotype (ZFMKMYR9482B1). H: M paratype (ZFMK-MYR 9482B2). A: Head, frontal view. B: Antenna. C: Sensilla basiconica on antennomeres 5 and 6. D: Apical disc with four sensory cones. E: Mouth parts, dorsal view. F: Mouth parts, ventral view. G: Anterior body, lateral view. H: Tergites, lateral view. Abbreviations: ac = apical cone; ag = anterior gonopod; an = antenna; br = body ring; co = collum; gn = gnathochilarium; le = leg; lb = labrum; ms = macrosetae; mz = metazonite; om = ommatidia; oz = ozopore; pg = posterior gonopod; pl = pleurite; pz = prozonite; sb = sensilla basiconica; sp = spiracle; st = sternite. I–VII indicates the number of antennomeres. The white arrow on (B) indicates the row of striae at the anterior margin of the antennomeres and on (H) indicates the lateral, ridge-like extension of the prozonite. Scale bars: A, G, H = 100 µm; B, D–F = 20 µm; C = 10 µm.

FIGURE 4. Theratta mannavan n. sp., SEM. A–D: M paratype (ZFMK-MYR 9483A). E, F: M holotype (ZFMK-MYR 9482B1). A: Tergites, dorsal view. B: First three leg pairs with gonopore, ventral view. C: Gonopore, posterior view. D: Detail of gonopore, ventral view. E: Leg. F: Paronychium. Abbreviations: cl = claw; cx = coxa; cxp = coxal pouch; fe = femur; le = leg; mz = metazonite; oz = ozopore; pe = penes; pf = prefemur; pn = paronychium; po = postfemur; pz = prozonite; sp = spiracle; st = sternite; ta = tarsus; ti = tibia; to = trochanter; vdo = vasa deferentia opening. The white arrow on (A) indicates the row of striae at the anterior margin of the metazonite. Scale bars: A = 200 µm; B, C, E = 20 µm; D, F = 10 µm.

FIGURE 5. Theratta mannavan n. sp., SEM. A, E, F: M holotype (ZFMK-MYR 9482B1). B: M paratype (ZFMK-MYR 9483A). C: F paratype (ZFMK-MYR 9482C). D: M paratype (ZFMK-MYR 9482B2). A: Telson, ventral view. B: Telson, lateral view. C: Female gonopore, ventral view. D: Gonopods, lateral view. E: Gonopods, posterior view. F: Gonopods, posterio-lateral view. Abbreviations: av = anal valve; cx = coxa; cxp = coxal pouch; fe = femur; go = gonopore; L = lamellae; le = leg; mp = mesal process; oz = ozopore; pbr = penultimate body ring; pf = prefemur; pl = pleurite; po = postfemur; st = sternite; ta = tarsus; te = telson; ti = tibia; ve = external valve of vulva; vi = internal valve of vulva. I–IV indicates the number of podomeres of gonopods. The black arrow on (E, F) indicates the remnant of podomere divisions of gonopods and the white arrow on (E, F) indicates the distal process present on the mesal process of the anterior gonopod. Scale bars: A = 200 µm; B, C = 100 µm; D–F = 20 µm.

FIGURE 6. Theratta mannavan n. sp., SEM. A, D, F, J: M paratype (ZFMK-MYR 9483A). B, E: M holotype (ZFMK-MYR 9482B2). C: M paratype (ZFMK-MYR 11393). G, H, I: M paratype (ZFMK-MYR 9482B1). A: Gonopods, dorsal view. B, C: Anterior gonopod, anterior view. D: Anterior gonopod, posterior view. E: Anterior gonopod, mesal view. F: Body teeth. G: Teeth on the mesal process of the anterior gonopod. H: Feather like serrated setae. I: Posterior gonopod, posterior view. J: Posterior gonopod, anterior view. Abbreviations: L = lamellae; mp = mesal process; st = sternite. I–IV indicates the number of podomeres of gonopods. The white arrow on (I) indicates the remnant of podomere division on the posterior gonopod. Scale bars: A, C–E, I, J = 20 µm; B, H = 10 µm; F, G = 2 µm.