Thyropygus uncinatus ( Demange, 1961 ) Demange, 1961

Pimvichai, Piyatida, Enghoff, Henrik & Panha, Somsak, 2011, A revision of the Thyropygus allevatus group. Part 3: the T. induratus subgroup (Diplopoda: Spirostreptida: Harpagophoridae), Zootaxa 2941, pp. 47-68 : 57

Thyropygus uncinatus ( Demange, 1961) , new status

( Figs. 5 A–F, 10C–D)

Thyropisthus induratus uncinatus Demange, 1961: 137

Thyropygus allevatus uncinatus: Hoffman 1975: 136 , 137 fig. 6

Material examined. 10 males, 10 females THAILAND, Chonburi Province, Koh Sichang District, Koh Sichang, 13° 9ˏ 24˝ N, 100° 48ˏ 30˝ E. 30 June 2007. S. Panha, P. Pimvichai and members of Animal Systematics Research Unit leg., ( CUMZ), 10 males, 10 females THAILAND, Prachinburi Province, Prachantakham District, Ban Khamtanod, 14° 6ˏ 28˝ N, 101° 36ˏ 13˝ E. 19 August 2007. P. Prasankok leg., ( CUMZ), 3 males, 3 females THAI- LAND, Nakhonrachasima Province, Muang District, Simathani Hotel, 14° 58ˏ 25˝ N, 102° 4ˏ 48˝ E. 1 September 2007. S. Panha, H. Enghoff and P. Pimvichai leg., ( CUMZ). 10 males, 9 females THAILAND, Roi-Et Province, Chaturaphakphiman District, Nong Phue, 15° 49ˏ 34˝ N, 103° 31ˏ 11˝ E. 31 July 2010. J. Pimvichai, C. Pimvichai and P. Pimvichai leg., ( CUMZ). 10 males, 5 females THAILAND, Saraburi Province, Chalermprakiat District, Phukhae Botanical Garden, 14° 40ˏ 15˝ N, 100° 53ˏ 12˝ E. 24 June 2007. S. Panha, H. Enghoff, P. Pimvichai and members of Animal Systematics Research Unit leg., ( CUMZ). 10 males, 10 females THAILAND, Surin Province, Muang District, Phanom Sawai Forest Park, 14° 15ˏ 45˝ N, 103° 22ˏ 7˝ E. 26 April 2009. S. Panha and members of Animal Systematics Research Unit leg., ( CUMZ). 5 males THAILAND, Burirum Province, Muang District, Khao Kradong, 14° 56ˏ 28˝ N, 103° 5ˏ 22˝ E. 15 July 2010. Y. Seethuanok leg., ( CUMZ). 1 male, 1 female SIAM, Koh Chang. 27 September 1911. ( ZMUC).

Diagnosis. A species of the induratus subgroup. Differing from all other species in the subgroup by having anterior coxal fold (ac) with two acuminate processes, curving mesad.

Description. Adult males with 62–73 podous rings, no apodous rings. Length 16–23 cm, width 8.7–13.0 mm. Adult females with 66–73 podous rings, no apodous rings. Length 18–20 cm, width 10.1–13.3 mm. Overall color of living animal in some populations ( Fig. 10 C) dark brown, with prozonite brownish grey and posterior margins of metazona, epiproct and margins of paraprocts reddish brown. In some populations, overall color of living animal ( Fig. 10 D) reddish brown.

Gonopods ( Figs. 5 A–D): Anterior coxal fold (ac) ( Figs. 5 A–C) basally almost parallel-sided, distally with two acuminate processes: the outer shorter and smaller than the inner one. Posterior coxal fold (pc) ( Fig. 5 D) basally with moderately high lateral paracoxites (px); mesal process (pmp) forming shelf (sh) for accommodation of telopodite, directed distolaterad. Telopodite ( Figs. 5 E–F) leaving coxite over shelf of posterior coxal fold; femoral spine (fe) relatively long, curving in a horizontal plane, very distinctly crenulated along outer curvature, in situ resting against tip of tibial spine; tibial spine (ti) very long, slender, curving in an oblique-sagittal plane, its tip close to tip of fe, in situ resting between the two ac; apical part: lamellar lobe (ll) broad, rounded, transparent; palette (pa) simple, basally with an uncate subterminal lobe ventrally (ucl); distally with about seven to eight brownish blepharochaetae (bp).

Note. There is considerable variation in body size, colour and the shape of the two apical processes of ac; in some populations the latter are longer – especially the inner process can be very long, strongly curved (tip meeting with tip of opposite side) and forming a deep curve between the two processes of each ac. In some populations the femoral spine (fe) is relatively short and the crenulation along its outer curvature is not so distinct or may even be missing.

Discussion. Following Demange (1961), Hoffman (1975) regarded uncinatus as a subspecies of induratus due to similarity in form of the anterior coxal fold (ac). However, Hoffman mentioned that the paracoxites (px) are less developed than in induratus as shown in Attems’ fig. 60(a) (1936), and that uncinatus shares a unique character with allevatus , i.e., a crenulated femoral spine (fe) and a very characteristic small hooked lobe on the anterior side of prostatic lobe. Hoffman found the same structure in resimus and induratus so he suggested treating all of these species as a subspecies of allevatus . The ‘hooked lobe’ is the one we call the uncate subterminal lobe (ucl).

We prefer to elevate uncinatus to a full species due to the following differences in gonopod structures:

- The apical part of ac does show some similarity with induratus but differs in configuration and details. - The uncate subterminal lobe (usl) (Hoffman’s “hooked lobe) is present in uncinatus and other members of the induratus subgroup and is clearly different from the subterminal process present in allevatus s.s., which is not hook-like but forms a flattened crest. See also discussion at end of paper.

Figures

FIGURE 5. Thyropygus uncinatus (specimen from Koh Sichang, except B and C), gonopods. A: anterior view, left telopodite removed. B: anterior view, anterior coxal fold (specimen from Ban Nong Phue). C: anterior view, anterior coxal fold (specimen from Simathani Hotel) D: posterior view, left telopodite removed. E: left telopodite, posterior-mesal view. F: left telopodite, anterior-lateral view.

FIGURE 10. A, B: Thyropygus resimus, living males (specimens from A: Phu-Kum-Khao, B: Klong Larn waterfall National Park.). C, D: Thyropygus uncinatus, living male and female (specimens from C: Roi-Et (male), D: Phukhae Botanical Garden (female).