Tylopus sapaensis, 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 : 301

Tylopus sapaensis , new species

( Figs. 9 , 10 , 18 )

Material examined. — Holotype: 1 male in the bottle IEBR-93H with a label “ Lao Cai Province, Sa Pa, Hoang Lien National Park (22°08'– 22°23'N, 103°45'– 104°00'E), primary forest, 2000 m a.s.l., coll. Nguyen Duc Anh, 17 Jul.2007 ”.

Paratypes: 2 males, 1 female (IEBR-93P), same collection data as holotype .

Etymology. — “ sapaensis ”, an adjective to refer to the type locality.

Diagnosis. — This species is closely related to Tylopus topali , but differs from the latter in the larger body size of a mature individual, the setal formula on the metaterga, the prefemur and femorite of legs with microtubercles, and the gonopod process h shorter than spine z.

Description. — Size: Body length 29–[30] mm (male), 31–33 mm (female). Width of prozona 2.2–[2.3] mm (male), 2.3–2.9 mm (female) and metazona 3.0–[3.2] mm (male), 3.2–4.0 mm (female).

Colouration: Body castaneous brown or reddish brown, but prozona and pleura somewhat paler. Legs and antenna brownish yellow. Distal part of antennomere 6 and whole antennomere 7 blackish brown.

Head: Slightly broader than collum; labrum setose, supralabral parts less setose. Epicranial suture thin, distinct and dividing slightly convex frons into two parts; each part with 2 setae along epicranial suture. Antenna claviform, reaching body ring 4 laterally. Antennomere 2=3=4=5=6>7& 1 in length.

Collum: Slightly narrower than body ring 2, subtrapeziform. Surface somewhat smooth, shining, with two rows of 3+3 and 1(2)+1(2) setae. Axial line evident. Paratergum poorly developed, rounded 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. Metaterga 2–4 shining, somewhat smooth, without rugosity, but with a row of 2+2 setae on front half. Metaterga 5–18 shining, rugulose, especially on posteriormost body rings. Transverse sulcus present on metaterga 5–19, reaching base of paraterga on metaterga 7–19. Metaterga 5–17 with rows of 2+2 and 2+2 setae in front of and behind transverse sulcus, respectively. Metaterga 18–19 also with rows of 3+3 and 4+4 setae in front of and behind transverse sulcus, respectively. Axial line traceable. Waist between pro- and metazona deep, finely striate. Pleura with dense microgranules. Pleurosternal keels well developed on body rings 2–4, reduced as long caudal spine on body rings 4–15, completely absent on subsequent body rings ( Fig. 9A ).

Paraterga ( Fig. 9A ): Well-developed, slightly lower than metatergal surface. Caudal corner acute on body rings 2–5, beak-like on subsequent body rings, especially more protruding and pointed on body rings 13–19. Paraterga not surpassing posterior contour on body rings 2–12, but exceeding posterior contour on body rings 13–19. Calluses with one or two traces of setiferous incision on poreless or pore-bearing paraterga. Ozopores located on lateral side of paraterga 5, 7, 9–10, 12–13, 15–19.

Telson: Epiproct short, broadly truncated with two small terminal tubercles. Tip concave, with four spinnerets. Hypoproct trapeziform, with two small distolateral setiferous knobs ( Fig. 9B ).

Sterna: Male sterna sparsely setose; longitudinal suture faint, indistinct whereas transverse suture obviously visible. Sterna without any modification except for sternum 5 with a setiferous emarginated bifid trapeziform lamina between coxae 4 ( Fig. 9C ).

Legs: Slightly slender, about 1.5–1.7 times as long as midbody height, without tarsal brushes. Prefemora swollen. Ventral part of prefemora, femora densely setose and with dense microtubercles, but without larger tubercles.

Gonopod ( Figs. 9D,E , 10A–D ): Coxite cylindrical, long, subequal to femorite in length; distoventral part densely setose. Prefemur densely setose, and set off from femorite by an oblique sulcus. Femorite strong, grooved mesally, weakly constricted in middle, and enlarged distally, well demarcated from lamina l by a parabolically rounded sulcus laterally. Lamina l well developed, distal part produced into an erect, long spine s. Process h erect, shorter than spine s. Lobes m present, small whereas lobe n absent. Solenophore strongly coiled, completely sheathing flagelliform solenomere. Tip of solenophore pointed.

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

Figures

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

Fig. 10. Tylopus sapaensis, new species, holotype: left gonopod, mesal view (A), lateroventral view (B), dorsal view (C), and lateral view (D, E); Leg 9 (F).

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).