Siliquobolellus amicusdraconis gen. et, 2022

Pimvichai, Piyatida, Enghoff, Henrik, Panha, Somsak & Backeljau, Thierry, 2022, A new genus of Pseudospirobolellidae (Diplopoda, Spirobolida) from limestone karst areas in Thailand, with descriptions of three new species, Zoosystematics and Evolution 98 (2), pp. 313-326 : 313

Siliquobolellus amicusdraconis gen. et sp. nov.

Figs 2 , 3 , 6 , 7

Material studied.

Holotype. 1 male (CUMZ-D00149-1), Thailand, Uthaithani Province , Lan-Sak District, Hub Pa Tard; 15°22'37.13"N, 99°37'49.98"E; 119 m a.s.l.; 26 July 2020; P. Pimvichai, T. Backeljau and P. Prasankok leg.

Paratypes. 3 males (CUMZ-D00149-3), 3 females (CUMZ-D00149-2); same data as holotype .

Etymology.

The species epithet means "friend of the dragon" and refers to the type locality, which is shared with the "shocking pink dragon millipede", Desmoxytes purpurosea Enghoff, Sutcharit & Panha, 2007.

Diagnosis.

Differing from other species in the genus by having the tip of anterior gonopod crossing over with tip of opposite side, the two together delimiting a drop-shaped “window”, whereas in the other two species the tips of anterior gonopod are separated from each other; externally differing by its bright orange color on the anterior and posterior ends. In contrast, S. constrictus gen. et sp. nov. has a row of triangular dark brown spots middorsally on its body rings, while S. prasankokae gen. et sp. nov. has a row of rectangular dark brown spots middorsally on the body rings.

Description.

Adult males with 41 or 42 podous rings, 1 apodous ring. Length ~3 cm, diameter 2.7-2.9 mm. Adult females with 41-43 podous rings, 1-3 apodous rings. Length ~3 cm, diameter 2.8-3.1 mm.

Colour. Living animal mainly dark brown. Head, dorsal part of the first four body rings and telson orange, antenna light brown, middorsal metazona orange (Fig. 6A, B ).

Anterior gonopods (Fig. 3A, B, D, E ) with extremely small triangular process between coxae (st), with high coxae, apically narrow, curving mesad, tip crossing over with tip of opposite side, the two together delimiting a drop-shaped “window”. Telopodite flattened apically rounded, curving backward, directed distad, as a thumb-like process (Fig. 3B , arrow).

Posterior gonopods (Fig. 3C, F-K ) simple, rounded, with short, smooth coxal part (pcx); telopodital part (pt) twice the length of the pcx, lateral margin folding mesad, forming a deep concavity, the inner lateral margin expanded into rounded lamella, apically forming a canopy (Fig. 3J , arrow).

Female vulvae (Fig. 3L ): simple, valves prominent, the right valve slightly larger than the left valve.

DNA barcode.

The GenBank accession number of the COI barcode of the paratype is OP174621 (voucher code CUMZ-D00149).

Habitat.

Found under leaf litter and on rocks.

Distribution.

Known only from the type locality in Uthaithani Province, Thailand (Fig. 7 ).

Figures

Figure 2. External morphology of Siliquobolellus gen. nov. A - C. S. amicusdraconis gen. et sp. nov. A. Head, lateral view; B. Head, ventral view; C. Posterior end, lateral view; D. Posterior end, lateral view (S. prasankokae gen. et sp. nov.); E. Posterior end, lateral view (S. constrictus gen. et sp. nov.); F-I. S. prasankokae gen. et sp. nov.; F. Posterior end, ventral view; G, H. Male leg, latero-ventral view; I. Body rings, dorsal colour pattern; J. S. constrictus gen. et sp. nov., body rings, dorsal colour pattern. Av = anal valves; Gst = gnathochilarial stipes; IL = incisura lateralis Me = mentum; Mst = Mandibular stipes; Pre = preanal ring; Sub = subanal scale.

Figure 3. Siliquobolellus amicusdraconis gen. et sp. nov., holotype, gonopods (specimen from Hub Pa Tard, CUMZ-D 00149 - 1). A. Anterior gonopod, anterior view; B. Anterior gonopod, posterior view, arrow indicates a thumb-like process; C. Right posterior gonopod, lateral view; D. Anterior gonopod, anterior view; E. Anterior gonopod, posterior view; F. Right posterior gonopod, lateral view; G. SEM, Right posterior gonopod, latero-mesal view; H. SEM, Mesal part of right posterior gonopod, lateral view; I. SEM, Right posterior gonopod, latero-mesal view; J. SEM, Tip of right posterior gonopod, latero-mesal view, arrow indicates a canopy; K. SEM, lateral part of pt, latero-mesal view; L. 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; st = sternal process.

Figure 6. Live Siliquobolellus gen. nov. species from Thailand. A, B. S. amicusdraconis gen. et sp. nov. (from Hub Pa Tard), female (paratype, CUMZ-D 00149 - 2); C, D. S. prasankokae gen. et sp. nov. (from Pha Thai), male (holotype, CUMZ-D 00148 - 1).

Figure 7. Geographic location of the type localities of Siliquobolellus gen. nov. species.