Glyphiulus pseudocostulifer, 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 : 45-50

Glyphiulus pseudocostulifer , new species

( Figs. 1 , 2 )

Holotype. Male ( ZFMK MYR-10009 A ( TW411 )), Laos, Oudomxay Province, Ban Chom Ong, Tham Ketlin (F47- 120-011), 20°43′19″N, 101°45′59″E, 28 December 2014, leg. M. Vandermeulen.

Paratypes. 1 female ( ZFMK MYR-10009 ), same locality, together with holotype . 1 male ( CUMZ MYR-10008 A ( TW414 )), same locality, 27 December 2014, leg. M. Vandermeulen. 1 male ( ZFMK MYR-9994 A ( TW400 )) 1 female ( ZFMK MYR-9994 B ( TW401 )), Laos, Oudomxay Province, Ban Houay Soy, Tham Houay Soy (F47-120- 015), 20°42′37″N, 101°45′50″E, 29 December 2014, leg. H. Steiner and I. Ermakova. 1 male ( ZFMK MYR-10004 A ( TW412 )), Laos, Oudomxay Province, Ban Chom Ong, Tham Hou Nguak (F47-120-010), 20°42′54″N, 101°45′38″E, 27 December 2014, leg. D. Fröhlich and M. Laumanns.

Etymology. To emphasise the obvious similarities to G. costulifer Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2007 . Noun in apposition.

Diagnosis. This new species is especially similar to both G. steineri , new species, and G. costulifer , from Luang Prabang Province, Laos ( Golovatch et al., 2007b). With G. costulifer , it shares the following diagnostic characters: the unique legs 1, and anterior and posterior gonopod structural details. It differs from G. costulifer by the carinotaxic formula of the collum: 1–5+6a+pc+ma ( Fig. 1A, B ) (vs. 1–6+7a+pc+ma) and the carinotaxic formula of the midbody rings/segments: 2/2+I/i+3/3+I/i+2/2 ( Fig. 1A, B, D–H ) (vs. 2+I/i+3/3+I/i+2), coupled with the paramedian processes on male coxae 1 being much higher than the prefemur ( Fig. 2B, C ) (vs. lower than the prefemur), the apicomesal processes (d) on the anterior gonopods being long and slender ( Fig. 2H, I ) (vs. shorter and digitiform) and the presence of a very long and slender flagellum process (f) on the posterior gonopods ( Fig. 2J, K ) (vs. a shorter flagellum process). The differences between G. pseudocostulifer , new species, and G. steineri , new species, are found in the carinotaxic formula of the midbody rings as well as the gonopods (see further details below).

Description. Length of holotype 26.5 mm; adult paratypes 17.5–29.5 (males) or 20.8–27. 5 mm long (females); midbody rings/segments round in cross-section ( Fig. 1F ), their width (horizontal diameter) and height (vertical diameter) being similar; width in holotype 0.9 mm; in paratypes 1.0–1.3 (males) or 1.1–1.5 (females).

Colouration in alcohol ( Fig. 1 ), after nine years of preservation, uniformly greenish-golden to grey-brown, dorsal crests and porosteles usually dark brownish ( Fig. 1A, B, D, E, G, H ). Head light yellow, vertex dark brown to red brownish ( Fig. 1A, C ). Antennae, venter and legs yellowish to yellow brown ( Fig. 1A–C, E–G, I ). Eyes blackish ( Fig. 1A, C ).

Body with 60p+2a+T (holotype) rings; paratypes with 34–52p+5a+T (males) or 44–57p+2–6a+T (females). Eye patches transversely ovoid, each composed of 7–11 blackish, rather flat ommatidia in 3–5 irregular longitudinal rows ( Fig. 1A ). Antennae rather short and clavate ( Figs. 1A, C , 2G ), extending to ring 4 laterally, antennomeres 5 and 6 each with a small distoventral group or corolla of bacilliform sensilla ( Fig. 2H ). Gnathochilarium with a clearly separated promentum ( Fig. 2A ).

Head width = ring 2 <collum = midbody ring (close to 13th to 15th) >> ring 4 <5 <6 <7 <3 <8 <9 <10; body abruptly tapering towards telson on a few posterior-most rings ( Fig. 1H ). Postcollar constriction evident ( Fig. 1B ).

Collum with low evident crests, carinotaxy formula 1–5+6a+pc+ma ( Fig. 1A–C ), with 6+6 longitudinal crests starting from anterior edge, but both median crests interrupted at about caudal 1/4–1/3, being replaced there by 1+1+1 crests starting from posterior edge, lateral crests being longer than median one.

Following metaterga similarly strongly crested ( Fig. 1A–H ), especially from ring 5 on, whence porosteles commence ( Fig. 1A, B ), smaller tubercles in their stead on legless rings in front of telson due to lack of ozopores ( Fig. 1G, H ). Porosteles large, conical, round, directed caudolaterad, wider than high, ozoporiferous crests distinctly divided into two about midway, their frontal halves being higher ( Fig. 1A, B, D–H ). Carinotaxy formulae 2+I/i+3/3+I/i+2 on rings 2 and 3, as well as on the last 1 or 2 leg-bearing and legless rings ( Fig. 1A, B, G, H ); 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. 1D, E, G, H ).

Tegument finely alveolate- areolate ( Fig. 1A, B, D, E, G, H ), dull throughout. Fine longitudinal striations in front of stricture between pro- and metazonae, remaining surface of prozonae very delicately shagreened ( Fig. 1D, E ). Metatergal setae absent. Rings 2 and 3 with long pleural flaps.

Epiproct ( Fig. 1G–I ) 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. 1I ). Hypoproct slightly concave caudally, with 1+1 strongly separated setae near caudal margin ( Fig. 1I ).

Ventral flaps behind gonopod aperture on male ring 7 evident, distinguishable as rather low swellings with rounded flaps bent abruptly caudad ( Fig. 1C ).

Legs rather short and stout, on midbody rings about 3/4–3/5 as long as body diameter ( Figs. 1A, C, G, I , 2F ). Claw at base with an evident accessory claw about 1/3–1/4 the length of main claw.

Male leg pair 1 highly characteristic ( Fig. 2B, C ) in showing nearly fully developed, 5-segmented telopodites and a pair of rather small, subdigitiform, medially contiguous, but apically diverging coxal processes, higher than prefemur ( Fig. 2B, C ), with a group of a few strong setae at base.

Male leg pair 2 nearly normal, claw long and slender, coxa somewhat reduced, femur abbreviated on frontal face; penes broad, oblong-subtrapeziform, each with 4 or 5 setae distolaterally ( Fig. 2D ).

Male leg pair 3 modified, coxa especially slender and elongate ( Fig. 2E ).

Anterior gonopods ( Fig. 2H, I ) with a typical shield-like coxosternum, this being rather densely microsetose on caudal face ( Fig. 2I ), with a long and high, digitiform, apicomesal process (dp). Telopodite typical, rather small, slender, movable, 1-segmented, lateral in position, with 3 or 4 strong apical setae and a field of microsetae at base ( Fig. 2I ).

Posterior gonopods ( Fig. 2J, K ) compact, subtrapezoid, micropapillate medially on oral face ( Fig. 2K ); with a very long and slim flagellum process (f), a pointed tip ( Fig. 2J, K ); a lamelliform lobe (l) higher than caudal piece of coxite ( Fig. 2J ), membranous, wrinkled frontolaterally, with an apical field of coniform microsetae caudally ( Fig. 2K ). Coxite rather smooth, each mediolateral part of coxite with 13–17 strong, short and curved setae ( Fig. 2J, K ).

Figures

Fig. 1. Glyphiulus pseudocostulifer, new species, male holotype (ZFMK MYR10009A). A–C, anterior part of body, lateral, dorsal, and ventral views, respectively; D, E, midbody rings, dorsal and lateral views, respectively; F, cross-section of a midbody ring; G–I, posterior part of body, lateral, dorsal, and ventral views, respectively.

Fig. 2. Glyphiulus pseudocostulifer, new species, male holotype (ZFMK MYR10009A). A, gnathochilarium, ventral view; B, C, leg pair 1, oral and caudal views, respectively; D, leg pair 2, caudal view; E, leg pair 3, caudal view; F, midbody leg; G, antenna, lateral view; H, I, anterior gonopods, oral and caudal views, respectively; J, K, posterior gonopods, oral and caudal views, respectively. Abbreviations: ap, apicolateral process; dp, apicomesal processes; f, flagellum process; l, lamelliform lobe. Scale bar: A–G 0.1 mm, H–K 0.02 mm.