Glyphiulus houaphanhensis, Likhitrakarn & Jeratthitikul & Jirapatrasilp & Wesener, 2024

Likhitrakarn, Natdanai, Jeratthitikul, Ekgachai, Jirapatrasilp, Parin & Wesener, Thomas, 2024, Integrated taxonomy of three new species of Glyphiulus Gervais, 1847 (Diplopoda, Spirostreptida, Cambalopsidae) from Laos, Raffles Bulletin of Zoology 72, pp. 42-61 : 53-56

publication ID	https://doi.org/ 10.26107/RBZ-2024-0003
publication LSID	lsid:zoobank.org:pub:DC2582A7-C5DD-4726-9B59-3F2C00E9485E
persistent identifier	https://treatment.plazi.org/id/038A87F0-FFCE-E70E-2DC7-FC05FB84FBA8
treatment provided by	Felipe
scientific name	Glyphiulus houaphanhensis
status	sp. nov.

Treatment

Glyphiulus houaphanhensis , new species

( Figs. 5 View Fig , 6 View Fig )

Holotype. Male ( ZFMK MYR-10011 C), Laos, Houaphan Province, Xam Neua, Tham Lo (F48-125-119), 20°33′31.1″N, 104°01′24.2″E, 9 January 2014, leg. H. Steiner. GoogleMaps

Paratypes. 1 male ( CUMZ MYR-10005 A) , 1 male ( ZFMK MYR-10001 A), Laos, Houaphan Province, Xam Neua, Tham Long Ngeuang (F48-125-132), 20°32′20.1″N, 104°01′45.2″E, 15 January 2014, leg. H. Steiner. GoogleMaps 1 female ( ZFMK MYR-10000 A), Laos, Houaphan Province, Xam Neua, Tham Falang (F48-125-122), 20°33′29.9″N, 104°01′25.5″E, 9 January 2014, leg. H. Steiner. GoogleMaps 1 male, 2 females ( ZFMK MYR-9999 ), Laos, Houaphan Province, Xam Neua, Tham Bae (F48-125-117), 20°33′50.8″N, 104°03′30.7″E, 7 January 2014, leg. H. Steiner. GoogleMaps

Etymology. The species is named in allusion to the type locality — Houaphan Province, adjective.

Diagnosis. This new species is especially similar to G. percostulifer Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2007 , from Khammouan Province, Laos ( Golovatch et al., 2007b), with which it shares the following diagnostic characters: the unique carinotaxic formula of midbody rings, coupled with anterior and posterior gonopod structural details. It differs from G. percostulifer by the absence of ommatidia (vs. present in G. percostulifer ), the carinotaxic formula of the collum: 1+2c+3–4+5c+6a+pc+ma ( Fig. 5A, B View Fig ) (vs. 1–4+5a+pc+ma), coupled with the apicomesal processes (d) on the anterior gonopods being long and slender ( Fig. 6H, I View Fig ) (vs. broad and stout), and the apicolateral process (ap) on the anterior gonopods being large, curved and subdigitiform ( Fig. 6H, I View Fig ) (vs. small and rounded), and the presence of a slim and smooth flagellum process (f), with a pointed tip on the posterior gonopods ( Fig. 6J, K View Fig ) (vs. flagellum process plumose distally).

Description. Length of holotype 21.8 mm; that of paratypes 18.5–22.5 (males) or 18.5–22. 8 mm (females); midbody rings round in cross-section ( Fig. 5F View Fig ), their width (horizontal diameter) and height (vertical diameter) being similar; width of holotype 0.7 mm, of paratypes 0.9–1.0 (males) or 1.1– 1.3 mm (females).

Colouration in alcohol ( Fig. 5 View Fig ), after nine years of preservation, uniformly brownish or chestnut-brown to pallid, dorsal crests and porosteles usually dark brownish ( Fig. 5A–E, G, H View Fig ). Head, antennae, venter, and legs yellowish to pallid ( Fig. 5A–C, E–G, I View Fig ).

Body with 46p+4a+T rings (holotype); paratypes with 37–44p+4a+T (males) or 40–50p+3–4a+T (females) rings. Eye patches invisible ( Fig. 5A, C View Fig ). Antennae long and clavate ( Figs. 5A–C View Fig , 6B View Fig ), reaching behind ring 5 laterally, antennomeres 5 and 6 each with a small distoventral group or corolla of bacilliform sensilla ( Fig. 6B View Fig ). Gnathochilarium with a clearly separated promentum ( Fig. 6A View Fig ).

Head width = ring 3 = 6> 4 = 5 <7 = collum <midbody ring (close to 8th to 10th); body abruptly tapering towards telson on a few posteriormost rings ( Fig. 5H View Fig ). Postcollar constriction rather evident ( Fig. 5B View Fig ).

Collum with evident crested, carinotaxy formula 1+2c+3– 4+5c+6a+pc+ma ( Fig. 5A–C View Fig ), with 6+6 longitudinal crests starting from anterior edge, but both median crests interrupted in about caudal 2/3–3/4, being replaced there by similar 1+1+1 crests.

Following metaterga similarly strongly crested ( Fig. 5A–H View Fig ), especially from ring 5 on, whence porosteles commence ( Fig. 5A, B View Fig ), smaller tubercles in their stead on legless rings in front of telson due to lack of ozopores ( Fig. 5G, H View Fig ). Porosteles large, conical, round, directed caudolaterad, wider than high, ozoporiferous crests distinctly divided into two about midway, their frontal halves being higher ( Fig. 5A, B, D–H View Fig ). Carinotaxy formulae 2+I/i+3+I/i+2 on rings 2–4, as well as on the last 1 or 2 leg-bearing and legless rings ( Fig. 5A, B, G, H View Fig ); midbody rings showing all dorsal crests subdivided transversely (carinotaxy formulae 2/2+I/i+3/3+I/ i+2/2) and sharper, especially so lateral crests ( Fig. 5D–H View Fig ). Tegument rather smooth and shining, quite sparsely alveolate-areolate ( Fig. 5A, B, D, E, G, H View Fig ). Fine longitudinal striations in front of stricture between pro- and metazonae, remaining surface of prozonae very delicately shagreened ( Fig. 5D, E View Fig ). Metatergal setae absent. Rings 2 and 3 each with long pleural flaps. Epiproct ( Fig. 5G–I View Fig ) simple, regularly rounded caudally, faintly convex medially, with a rounded ridge in caudal part and an evident axial rib dorsally. Paraprocts regularly convex, each with premarginal sulci medially and a row of sparse setae at medial margin ( Fig. 5I View Fig ). Hypoproct transversely bean-shaped, slightly concave caudally, with 1+1 strongly separated setae near caudal margin ( Fig. 5I View Fig ). Ventral flaps behind gonopod aperture on male ring 7 evident, distinguishable as low swellings forming no marked transverse ridge ( Fig. 5C View Fig ).

Legs long and slender, on midbody rings nearly as long as body diameter ( Figs. 5A, C, E–G, I View Fig , 6G View Fig ). Claw at base with a strong accessory spine almost half as long as main claw ( Fig. 6G View Fig ).

Male leg pair 1 highly characteristic ( Fig. 6C, D View Fig ) in showing nearly fully developed, 5-segmented telopodites and a pair of rather high, subdigitiform, medially contiguous, but apically diverging coxal processes with a group of few strong setae at base.

Male leg pair 2 nearly normal, claw long and slender, anteriorly, coxa somewhat reduced, and femur abbreviated on frontal face; penes broad, oblong-subtrapeziform, each with 2 or 3 strong setae distolaterally ( Fig. 6E View Fig ).

Male leg pair 3 modified, coxa especially slender and elongate ( Fig. 6F View Fig ).

Anterior gonopods ( Fig. 6H, I View Fig ) with a typical shield-like coxosternum, the latter sparsely microsetose in anterior and lateral parts on caudal face ( Fig. 6I View Fig ), with a long, high, digitiform, apicomesal process (dp) and an obvious, curved, apicolateral process (ap). Telopodite typical, rather small, slender, movable, 1-segmented, lateral in position, with 2 or 3 strong apical setae and a field of microsetae at base ( Fig. 6I View Fig ). Posterior gonopods ( Fig. 6J, K View Fig ) compact, subtrapezoid, with a rather long, slim flagellum process (f), pointed tip ( Fig. 6J, K View Fig ; lamelliform lobe (l) higher than caudal piece of coxite, membranous, wrinkled frontolaterally, with an apical field of coniform microsetae laterally ( Fig. 6K View Fig ). Coxite smooth, each mediolateral part of coxite with 10–12 strong, short, and curved setae ( Fig. 6J, K View Fig ).

Remarks. Based on its uniform colouration lacking any discernible patterns and the absence of eyes, this species appears to have undergone evolutionary adaptations indicative of troglophily. It is exclusively reported within the confined cave systems in the Xam Neua area of Houaphan Province ( Fig. 7 View Fig ), Laos, unequivocally establishing its status as a species endemic to Laos.