Coxobolellus saratani, Pimvichai & Enghoff & Backeljau, 2022

Pimvichai, Piyatida, Enghoff, Henrik & Backeljau, Thierry, 2022, Two new millipede species of the genus Coxobolellus Pimvichai, Enghoff, Panha & Backeljau, 2020 (Diplopoda, Spirobolida, Pseudospirobolellidae), ZooKeys 1128, pp. 171-190 : 171

Coxobolellus saratani sp. nov.

Figs 2 , 4 , 5

Material studied.

Holotype ♂ (CUMZ-D00153-1), Thailand, Loei Province, Muang District, Phu Pha Lom ; 17°32'30"N, 101°51'38"E; 370 m a.s.l.; 25 September 2021; P. Pimvichai, P. Prasankok and S. Saratan leg. Paratypes. 7 ♂♂, 9 ♀♀; same data as holotype (CUMZ-D00153-2) .

Etymology.

The species is named after Mr Sathit Saratan, who always supports the authors during fieldwork and who is a devoted millipede collector.

Diagnosis.

Differing from all other species in the genus by having the tip of the telopodital part (pt) forming a flattened, pointed lobe, directed distad (Fig. 2C, F-H ), whereas in the other 11 Coxobolellus species the tip of the telopodital part of the posterior gonopod curves mesad or forms a rounded lobe.

Description.

Adult males with 51-55 podous rings. Length ca 6-7 cm, diameter ca 4.9-5.2 mm. Adult females with 52 or 53 podous rings. Length ca 6-8 cm, diameter ca 5.6-6.1 mm.

Colour. Living animal greenish grey except for dark brown antennae and legs (Fig. 4A ).

Anterior gonopods (Fig. 2A, B, D, E ) with high coxae, apically obliquely truncated, mesal margins straight, diverging, delimiting a V-shaped space between both coxae, posterior surface with relatively high ridge laterally for accommodation of telopodite. Telopodite (at) projecting slightly over anterior gonopod coxa (cx), subapically strongly constricted, apically forming a triangular process with pointed tip and a pigmented brown node (Fig. 2B, E , unlabeled arrow).

Posterior gonopods (Fig. 2C, F-J ) simple, rounded, with long, smooth coxal part (pcx); telopodital part (pt) fairly long, apically pointed, directed distad, with a sharp, pointed, folded process in the middle (Fig. 2C, F-H ), with a small transverse ridge near tip protruding from mesal surface, with serrate mesal margin (Fig. 2J , unlabeled arrow).

Female vulvae (Fig. 2K ): valves prominent, of equal size.

DNA barcodes.

The GenBank accession numbers are:

Holotype CUMZ-D00153-1: COI = OP580098; 16S rRNA = OP580513.

Paratype CUMZ-D00153: COI = OP580097; 16S rRNA = OP580512.

Habitat.

Found under leaf litter and crawling around (on the rock and stairs).

Distribution.

Known only from the type locality in Loei Province, Thailand (Fig. 5 ).

Figures

Figure 2. Coxobolellus saratani sp. nov., holotype, gonopods (CUMZ-D 00153 - 1) A, D anterior gonopod, anterior view B, E anterior gonopod, posterior view, unlabeled arrows indicate a pigmented brown node C, F, G left posterior gonopod H SEM, right posterior gonopod, posterior-mesal view I SEM, mesal part of posterior gonopod, posterior-mesal view J SEM, tip of posterior gonopod, posterior-lateral view K SEM, left female vulva, posterior-mesal view. at = anterior gonopod telopodite; cx = coxa; oeg = opening of efferent groove; op = operculum of vulva; pcx = coxal part of the posterior gonopod telopodite; pt = telopodital part of the posterior gonopod telopodite.

Figure 4. Live Coxobolellus species from Thailand A C. saratani sp. nov., male (paratype, CUMZ-D 00153 - 2) B C. serratoligulatus sp. nov., male (holotype, CUMZ-D 00154 - 1).

Figure 5. Distribution of the species of Coxobolellus in Thailand. Droplets vary in size to improve readability.