Tylopus roseiparaterga, Nguyen, 2012

Nguyen, Anh D., 2012, Tylopus Millipedes In Vietnam (Diplopoda: Polydesmida: Paradoxosomatidae: Sulciferini), With Descriptions Of Five New Species, Raffles Bulletin of Zoology 60 (2), pp. 289-311 : 293-298

Tylopus roseiparaterga , new species

( Figs. 5 , 6 , 18 )

Material examined. — Holotype: Male in the bottle IEBR-97H, with a label “ Vinh Phuc Province, Tam Dao National Park (21°21'– 21°42'N, 105°23'– 105°44'E), forest, 900–1000 m a.s.l., coll. Nguyen Duc Anh & Jun-ichi Kojima, 15–18 Oct.2010 ”.

Paratypes: 6 males, 1 female (IEBR-97P), same data as holotype .

Etymology. — “ roseiparaterga ”, a noun in apposition, and emphasizes the pink paraterga.

Diagnosis. — The species can be distinguished from its congeners by the pink paraterga and by gonopod conformation: lamina l subtrapeziform; process h short, thin,

finger-shaped; solenophore strongly coiled; lobe m present; lobe n and spine z absent.

Description. — Size: Body length 34–[36] mm (male), 30–31 mm (female). Width of prozona [2.6]– 2.8 mm (male), 2.4–2.5 mm (female) and metazona 3.4–[3.5] mm (male), 3.2–3.3 mm (female).

Colouration: Prozona and metaterga with a median broad whitish-yellow stripe and two paramedian small brown regions. Paraterga pink (living specimens) or paler (preserved specimens). Pleura and distal podomeres brown. Sterna yellowish brown. Most antennomeres brown except for distal part of antennomere 6 and whole antennomere 7 blackish brown.

Head: Slightly broader than collum. Labrum densely setose. Epicranial suture thin, evident, dividing frons into two parts; each part with 2 setae along epicranial suture. Antenna claviform, long, reaching body ring 4 laterally. Antennomere 3>2=4=5>6>1& 7 in length.

Collum: Slightly narrower than body ring 2; surface shining, more or less smooth, with two rows of 3+3 and 1+1 setae. Axial line evident. Paratergum very small, with a setiferous incision laterally.

Body ring 4<3<2= 5 in width, body parallel-sided on rings 5-16, thereafter gradually tapering towards telson. Surface of metaterga 2–4 more or less smooth whereas other metaterga considerably rugose. Transverse sulcus narrow, concave, present on metaterga 4-19, but fully developed (reaching base of paraterga) from metatergum 5. Anterior half of metaterga 2–19 with row of 2+2 setae ( Fig. 5A ). Axial line only evident in anterior half of metaterga. Waist between pro- and metazona broad, finely striate. Pleura with dense microgranules. Pleurosternal keels well developed on body rings 2–4, reduced as small caudal spine on body rings 5–9, and completely absent on subsequent body rings.

Paraterga: Well developed, slightly lower than metatergal surface. Caudal corner somewhat rounded on body rings 2–13, but gradually protruding, acute on body rings 14–19. Paraterga not surpassing posterior contour of metaterga 2–13, but surpassing posterior contour of metaterga 14–19. Calluses very small, somewhat reduced on poreless paraterga, but more developed on pore-bearing paraterga, with two traces of setiferous incisions laterally.

Telson: Epiproct long, truncated with two small terminal tubercles. Tip concave, with four spinnerets. Hypoproct subtrapeziform, with two small distolateral setiferous knobs ( Fig. 5B ).

Sterna: Sparsely setose, without any modifications; longitudinal and transverse sutures obvious. Male sternum 5 with a highly elevated, setiferous, bifid lamina between coxae 4 ( Fig. 5C ).

Legs: Thin and slender, about 1.3–1.4 times as long as midbody height. Prefemora not swollen. Ventral tubercles present on all legs. Tarsal brushes present on leg pairs 1–15, thinner on leg pairs 16–21 and absent on subsequent leg pairs. Ventral part of prefemora and femora with long setae ( Fig. 5D ).

Gonopod ( Figs. 5E,F , 6A–C ): Coxite cylindrical, slightly shorter than femorite; distoventral part sparsely setose. Prefemorite densely setose, set off from femorite by an oblique sulcus laterally. Femorite slender, slightly twisted, and demarcated from postfemoral region by a distinct transverse sulcus laterally. Lamina l present, subtrapeziform; spine z absent. Process h thin, short and finger-shaped. Lobe m moderate whereas lobe n absent. Solenophore completely sheathing solenomere and twisted twice.

Distribution. — Known only from the type locality ( Fig. 18 )

Figures

Fig. 5. Tylopus roseiparaterga, new species, holotype: body rings 10–11, dorsal view (A); hypoproct, ventral view (B); sternite 5, posterioventral view (C); legs 9, (D); left gonopod, mesal view (E) and lateral view (F). Scale bars = 1 mm.

Fig. 6. Tylopus roseiparaterga, new species, holotype: left gonopod, lateral view (A); postfemoral region, lateral view (B) and submesal view (C).

Fig. 18.Distribution map ofthe millipede genus Tylopus Jeekel, 1968 in Vietnam. 1: Sa Pa, Lao Cai Prov. (T. crassipes, T. procurvus, T. nodulipes, T. sigma, T. sapaensis, T. maculatus, T. magnicus); 2: Van Ban, Lao Cai Prov. (T. crassipes, T. nodulipes); 3: Xuan Son NP (T. strongylosomoides, T. golovatchi); 4: Tam Dao NP (T. tamdaoensis, T. roseiparaterga, T. strongylosomoides); 5: Cuc Phuong NP (T. granulatus, T. hilaroides, T. topali); 6: Pu Mat NP (T. nodulipes); 7: Huong Son, Ha Tinh prov. (T. nodulipes); 8: Bach Ma–Ba Na NP (T. hilaris, T. multilatus); 9: Ngoc Linh Mts., Kon Tum prov. (T. hilaris, T. phanluongi); 10: Bi Doup–Nui Ba NP (T. spinisterna).