Glyphiulus subbedosae Likhitrakarn, Golovatch & Panha

Likhitrakarn, Natdanai, Golovatch, Sergei I., Inkhavilay, Khamla, Sutcharit, Chirasak, Srisonchai, Ruttapon & Panha, Somsak, 2017, Two new species of the millipede genus Glyphiulus Gervais, 1847 from Laos (Diplopoda, Spirostreptida, Cambalopsidae), ZooKeys 722, pp. 1-18 : 2-4

Glyphiulus subbedosae Likhitrakarn, Golovatch & Panha sp. n. Figs 1A, B, 2, 3, 4

Type material.

Holotype ♂ (CUMZ), Laos, Luang Prabang Province, Chomphet District, Kacham Waterfall, 442 m a.s.l., 19°38'57"N, 100°04'52"E, 30.08.2014, leg. C. Sutcharit and R. Srisonchai.

Paratypes. 4 ♂, 7 ♀ (CUMZ), 1 ♂, 2 ♀ (ZMUM), same locality, together with holotype. 4 ♂, 1 ♀ (CUMZ), same District, small waterfall near road, 405 m a.s.l., 19°41'54"N, 102°07'52"E, 01.07.2014, leg. R. Srisonchai.

Etymology.

To emphasize the obvious similarities to G. bedosae Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2007.

Diagnosis.

This new species is particularly similar to G. bedosae , with which it shares the following diagnostic characters: the presence of a row of several strong setae near the median marginal ridge on the paraprocts, combined with the gnathochilarium being considerably less densely setose on the caudal face, and the anterior gonopods showing a pair of smaller apical. It differs from G. bedosae primarily by the larger lateral teeth on the coxosternal plate. See also Key below.

Description.

Length of holotype ca 12.1 mm; that of paratypes 12.1-23.1 (♂) or 12.2-18.3 mm (♀); midbody segments round in cross-section (Fig. 2L), their width (horizontal diameter) and height (vertical diameter) similar, width of holotype 1.0 mm, of paratypes 0.8-1.5 (♂) or 0.9-1.2 mm (♀).

Coloration of live animals brownish yellow (Fig. 1A, B); unfaded specimens variegated, with contrasting dark brownish, lateral, longitudinal stripes above ozopores on each side, both interrupted mid-dorsally by a light wide axial stripe; vertex dark brown, anterior half of collum blackish to dark brown; venter, legs and telson light yellowish to brownish yellow; ocellaria blackish; coloration in alcohol similar, but body brownish yellow to light brownish; vertex dark brown to brown, anterior halves of both collum and head light brown to dark brown; eyes blackish to brownish.

Body with 50p+2a+T segments (holotype); paratypes with 39-58p+2(3)a+T (♂) or 41 –47p+2– 4a+T (♀) segments. Eye patches transversely ovoid, each composed of 10-18 rather flat ocelli in 4 or 5 irregular longitudinal rows (Fig. 2D). Antennae short and clavate (Figs 1A, 2A, D, E), extending behind segment 3 laterally, antennomeres 5 and 6 each with a small distoventral group or corolla of bacilliform sensilla (Fig. 2F, G). Gnathochilarium with a clearly separated promentum (Figs 2E, 4B).

Head width = segment 2 <collum = midbody segment (close to 13th to 15th)> segment 3 = 6> 4 <5 <7 <8 = 10; body abruptly tapering towards telson on a few posteriormost segments (Fig. 2P). Postcollar constriction very evident (Fig. 2B).

Collum with 7+7 longitudinal crests starting from anterior edge, but both median crests interrupted in about caudal 1/2-1/3, being replaced there by similar 1+1+1 crests; carinotaxy formula 1-6+7a+pc+ma (Fig. 2B, C).

Following metaterga similarly strongly crested (Figs 1A, 2 A–C, H, I, O, P), especially from segment 5 on, whence enlarged porosteles commence, these becoming completely absent from legless segments due to loss of ozopores (Fig. 2P). Porosteles large, conical, round, directed caudolaterad, wider than high (Fig. 2N). Midway metatergal crests on segment 5 distinctly divided into two at about 1/3 of metatergal height, each half rather evident and well rounded, nearly undivided and small tubercles in their stead in legless segments in front of telson (Fig. 2B, I, O, P). Carinotaxy formulae 3+I+4+I+3 and 3+i+3+i+3, the former standing for frontal row of crests, the latter for caudal one, both fairly independent (Fig. 2 A–C, H, I, O, P).

Tegument extremely delicately and quite sparsely alveolate-areolate (Fig. 2K), dull throughout. Fine longitudinal striations in front of stricture between pro- and metazona, remaining surface of prozona very delicately shagreened (Fig. 2J). Metatergal setae absent. Segments 2 and 3 each with long pleural flaps. Limbus extremely finely and regularly spiculate (Fig. 2K). Epiproct (Fig. 2 O–Q) simple, regularly rounded caudally, faintly convex medially. Paraprocts regularly convex, each with premarginal sulci medially and with a row of several strong setae at medial margin (Fig. 2Q). Hypoproct transversely bean-shaped, slightly concave caudally, with 1+1 strongly separated setae near caudal margin (Fig. 2Q).

Ventral flaps behind gonopod aperture on ♂ segment 7 barely distinguishable as low swellings forming no marked transverse ridge.

Legs short, on midbody segments about 2/3 length of body height (Figs 2A, H, M, O, 4D). Claw at base with a strong accessory spine almost half as long as main claw (Fig. 4D). Tarsi and tarsal setae very delicately fringed.

♂ legs 1 highly characteristic (Figs 3 A–C, 4C) in being very strongly reduced, represented only by a sternum devoid of any median or paramedian structures, but carrying 1+1 strongly separated prongs, both evidently curved posteriad and bearing several strong setae and rudimentary, 2-segmentel leg vestiges at base on caudal face (Figs 3B, C, 4C).

♂ legs 2 very slightly hypertrophied (Figs 3D, E, 4F), only claw and, anteriorly, coxa somewhat reduced; penes broad, oblong-subtrapeziform, each with 4-6 strong setae distolaterally (Figs 3D, E, 4D).

♂ legs 3 modified in having coxa especially slender and elongate (Figs 3F, 4G).

Anterior gonopods (Figs 3 G–J, 4E) with a typical shield-like coxosternum which is rather sparsely microsetose on caudal face (Fig. 3H, J) and shows its inner, somewhat elevated, axe-shaped processes, as well as small, but obvious, apicolateral teeth. Telopodite small, but movable, 1-segmented, lateral in position, with 2 or 3 strong apical setae and a field of microsetae at base (Fig. 3H, I), modestly higher than adjacent lateral corner of coxosternum.

Posterior gonopods (Figs 3 K–P, 4H, I) compact, broadly subquadrate, coxite medio-apically with a long, plumose, apical flagellum (f) (Fig. 3M, N) with evident spikes paramedially (Fig. 3 K–O); caudal piece (telopodite) (b) microsetose laterally, both b and strongly setose lobes (l), lower than frontal, microsetose, median piece (a).

Remarks.

The granulatus-group currently encompasses 34 described species. The above new one is only the second species in this group to be reported from Laos. Two populations have been found, each from near a forest at a waterfall, and both show the remarkable colour pattern as described above.