Thyropygus opinatus ( Karsch, 1881 ) Karsch, 1881

Pimvichai, Piyatida, Enghoff, Henrik & Panha, Somsak, 2009, A revision of the Thyropygus allevatus group. Part 1: the T. opinatus subgroup (Diplopoda: Spirostreptida: Harpagophoridae), Zootaxa 2016, pp. 17-50 : 27-29

Thyropygus opinatus ( Karsch, 1881) , n. comb.

( Figs. 6 A–F, 18A)

Spirostreptus opinatus Karsch, 1881: 23

Spirostreptus opinatus: Pocock 1889: 294, 1893: 401 Spirostreptus regis Pocock, 1889: 297 (?)

Spirostreptus andersoni Pocock, 1893: 401 (nomen nudum?) (?) Cornugonus opinatus: Demange, 1961: 178

Material: 1 male MYANMAR, Malewoon, 10° 14ˏ 0˝ N, 98° 37ˏ 0˝ E. Fea leg., ( ZMUC). This specimen comes from the same series as that illustrated by Demange (1961), studied earlier by Pocock (1893) and now belonging to MNHN, 3 males, 2 females THAILAND, Petchaburi Province, Cha-Um district, at Nakwang cave, 12° 51ˏ 26˝ N, 99° 56ˏ 29˝ E. 6 October 2008. H. Enghoff, S. Panha, P. Pimvichai and members of Animal Systematics Research Unit leg., ( CUMZ), 1 male THAILAND, Prachuap Khirikhan Province, Bang Saphan district, Ban Grude, 11° 16ˏ 25˝ N, 99° 33ˏ 1˝ E. 12 October 2008. C. Sutcharit and P. Tongkerd leg., ( CUMZ), 3 males THAILAND, Prachuap Khirikhan Province, Khao Sam Roi Yot National Park, ca. 100 m before Kaeo cave, 12° 11ˏ 17˝ N, 99° 59ˏ 27˝ E. 21 July 2006. G. Hantke & F. Brand leg., ( SMF) and 4 males THAILAND, Prachuap Khirikhan Province, Khao Sam Roi Yot National Park, ca. surrounding of 10 m from Kaeo cave, 12° 12ˏ 6˝ N, 99° 59ˏ 25˝ E. 22 July 2006. G. Hantke & F. Brand leg., ( SMF, ZMUC)

Diagnosis: A species of the opinatus subgroup. Spatulate lobe (sl) at apical part of telopodite terminating in a sharp brown spine. Similar in this respect to T. floweri , T. implicatus and T. erectus . Differing from these species by mesal margin of anterior coxal fold (alp) serrated or with a single denticle, with a small spine (ss) at base of apical part, opposite the origin of tibial spine, and the mesal process of anterior coxal fold (amp) almost as long as lateral process.

Description: Adult males with 62–70 podous rings, no apodous rings. Length ca. 19–21 cm, width ca. 10.5–11.5 mm. Adult females with 70 podous rings, no apodous rings. Length ca. 18 cm, width ca. 9.8–10.8 mm. Overall color of living animal ( Fig. 18A ) black. Legs and antennae reddish brown. Epiproct and margins of paraprocts yellowish brown.

Gonopods ( Figs. 6 A–F): Anterior coxal fold (ac): lateral process (alp) broadly expanded and apically gradually narrowed, mesal margin with fine serrations ( Demange 1961: fig. 244) or smooth with a single denticle ( Figs. 6 A–C, Pocock 1889: fig. 2b); mesal process (amp) almost as long as lateral process, slender, straight, directed distad, terminally slightly curved, pointed, sometimes crossing over with opposite amp ( Figs. 6 A–C). Posterior coxal fold (pc) ( Fig. 6 D) distally with two processes: mesal process (pmp) a rounded lobe, shorter than lateral process (plp) and separated from plp by deep, rounded sinus; lateral process (plp) a large, smooth, rounded node, projecting further caudad than mesal process. Telopodite ( Figs. 6 E–F): Femoral spine (fe) long, slender, very distinctly crenulated along outer curvature, in situ resting against posterior surface of alp; telopodite distally to fe with a massive, broad, round lobe (lo) projecting distolaterally; tibial spine (ti) long, slender, recurved, in anterior view crossing over with fe and reaching mesal end of lo; apical part: spatulate lobe (sl) terminating in a sharp brown spine (very slender in Nakwang specimens); a small spine (ss) at base of apical part, opposite the origin of ti; palette (pa) simple, with a longitudinal rounded crest (cr) near tip, distally with about ten brownish blepharochaetae (bp).

Distribution ( Fig. 20): Described from MYANMAR, Tenasserim, without an exact locality ( Karsch, 1881). Subsequently recorded from Sullivan Island (10° 50ˏ 0˝ N, 98° 15ˏ 0˝ E) by Pocock (1889). The Myanmar specimens studied by us, Pocock (1893) and Demange (1961) are from Malewoon, Tenasserim (10° 14ˏ 0˝ N, 98° 37ˏ 0˝ E). We here record the species as new to Thailand based on specimens from Petchaburi and Prachuap Khirikhan Provinces. The records from King Island ( Pocock 1889), and from "S. Tenasserim" ( Pocock,1893) are fraught with serious doubts (see notes) and are not shown on the map.

Notes: This species presents several unresolved problems. The original description ( Karsch, 1881) was said to be based on a male, but as usual, Karsch did not describe the gonopods. The whereabouts of the type specimen are unknown. The next mention of opinatus was by Pocock (1889) who reported it from Sullivan Island. Pocock gave a relatively good description, including a small gonopod drawing. In 1893, Pocock recorded opinatus from Malewoon and further noted that “Two young examples collected by Oates in S. Tenasserim are doubtfully referred to this species” and further that “This species was originally described from Tenasserim and was subsequently procured by Dr. Anderson from the Mergui Archipelago”. The latter statement must refer to the name “? Sp. andersoni ” Pocock, 1889 listed in the synonymy of opinatus by Pocock (1893) with an exact reference to the page and figure number in his 1889 paper and a note that this name is based on a young specimen. The strange thing is that in Pocock (1889) there is no Spirostreptus andersoni ; instead there is, on the cited page and under the cited figure number, a Spirostreptus regis Pocock, 1889 , based on a single female from King Island. The length of this specimen was given as 55 mm which does suggest a juvenile. It seems most likely that andersoni is a lapsus calami for regis , maybe due to confusion with Spirobolus andersoni Pocock, 1889 , described just two pages after Spirostreptus regis . Demange (1960) found specimens of neither andersoni nor regis in the Natural History Museum of London.

Demange (1961) based his description of opinatus on a specimen from Malewoon examined by Pocock (1893), and we have carried on this understanding of opinatus , being aware that rediscovery of Karsch’s type specimen may require a revision. Pocock’s (1889) gonopod drawing based on the specimen he described from Sullivan Island bears a strong resemblance to our Fig. 6 A, although the lateral process (alp) of the anterior gonopod fold looks slightly narrower in the Sullivan Island specimen. Considering that the specimen illustrated by Demange (1961) is again slightly different from the one from the same series studied by us, in this case with an even broader alp, and further considering the variability among the new Thai specimens, we accept the record of opinatus by Pocock (1889) as belonging to this species as understood here.

Figures

FIGURE 6. (A, D, E, F): Thyropygus opinatus, gonopods. A: anterior view, left telopodite removed (specimen from Malewoon). B: anterior view, anterior coxal fold (specimen from Nakwang cave). C: anterior view, anterior coxal fold (specimen from Ban Krude). D: right coxa, posterior view. E: right telopodite, anterior view. F: right telopodite, posterior view.

FIGURE 18. A: Thyropygus opinatus, living male. B: Thyropygus bearti, living male. C: Thyropygus bispinispatula, living male. D: Thyropygus brachyacanthus, living male.