Glyphiulus formosus ( Pocock, 1895 )

Jiang, Xuan-Kong, Hennen, Derek A., Chen, Hui-Ming & Xie, Zhi-Cai, 2020, First description of the male of Glyphiulus formosus (Pocock, 1895) (Diplopoda Spirostreptida: Cambalopsidae) from China, Zootaxa 4861 (2), pp. 281-289 : 282-288

publication ID	https://doi.org/ 10.11646/zootaxa.4861.2.8
publication LSID	lsid:zoobank.org:pub:7A2EDE06-5BEB-4EB4-8268-5A2F6B5EA63E
DOI	https://doi.org/10.5281/zenodo.4427137
persistent identifier	https://treatment.plazi.org/id/042AAA07-7119-FFF2-FF5E-FD16359EFE58
treatment provided by	Plazi
scientific name	Glyphiulus formosus ( Pocock, 1895 )
status

Treatment

Glyphiulus formosus ( Pocock, 1895)

( Figures 1 View FIGURE 1 ‒22)

Cambalomorpha formosa Pocock, 1895: 364 ; Attems, 1914: 295.

Glyphiulus formosus Mauriès, 1970: 513 , 517; Mauriès, 1977: 246; Wang & Mauriès, 1996: 85; Jeekel, 2004: 52; Golovatch et al., 2007a: 11; Golovatch et al., 2007b: 418; Jiang et al., 2018: 156.

Material examined. Near-topotypes: 4 males, 10 females and 3 juveniles, China, Guangdong Province, Shenzhen City, Tanglangshan Suburb Park , 22°34’17” N, 113°58’44” E, alt. 270 m, 13 October 2018, X.K. Jiang and H.M. Chen leg. ( IBGAS) GoogleMaps .

Diagnosis. This species belongs to the G. javanicus group, and it can be separated from other species from this group except for G. recticullus Zhang & Li, 1982 and G. calceus Jiang et al., 2018 by (1) the crests on collum complete and developed, carinotaxic formula I–III + P + M; (2) male legs I two-segmented, obviously shorter than coxosternal process; (3) coxite process of anterior gonopod prolonged and axe-shaped; (4) male femora VI and VII slightly inflated. G. formosus is very similar to G. recticullus , but it can be distinguished by the flagellum of the posterior gonopod being incurved. G. formosus can be diagnosed from G. calceus by (1) coxite process of anterior gonopod relatively broader and shorter; (2) flagellum of posterior gonopod more slender; (3) male femora VI and VII slightly inflated, whereas they are unmodified in G. calceus .

Description. Body size ca. 27–35 mm long and 1.6–2.0 mm wide. Body rings with 52–58p + 4–2a + T.

Color. Generally orange-yellow ( Fig. 1 View FIGURE 1 ); epicranium purple ( Fig. 2A View FIGURE 2 ); clypeus and labrum cream; color of collum and subsequent two rings variable, from cream ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 A–B) to fuscous; one thin, purple dorsal median line ( Figs 1A View FIGURE 1 , 2C View FIGURE 2 ) and two purple lateral bands ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 B–F) extending from fourth ring to the last ring of trunk; the lateral band covering the ozoporiferous tubercles to the lateralmost crests ( Figs 1B View FIGURE 1 , 2D View FIGURE 2 ); telson light yellow ( Fig. 2 View FIGURE 2 E–F); antennae purple ( Fig. 2 View FIGURE 2 A–B); legs cream-colored ( Fig. 1B View FIGURE 1 ).

Head. Each eye patch with 10–12 pigmented ommatidia arranged in two irregular linear rows ( Figs 2 View FIGURE 2 A–B, 3A–B). Antennae stout. Antennomeres V expanded distally ( Figs 2B View FIGURE 2 , 3B View FIGURE 3 ). Antennae apical cones obvious (3 cones lost in Fig. 5A View FIGURE 5 ). Clypeus with four teeth medially ( Fig. 4A View FIGURE 4 ). Gnathochilarium with a separate promentum, oligotrichous ( Fig. 4A View FIGURE 4 ). Mandibular gnathal lobe with a large external tooth and three small internal teeth ( Fig. 5B View FIGURE 5 ).

Collum. All crests on collum complete and fully developed, carinotaxic formula I–III + P + M ( Figs 2 View FIGURE 2 A–B,

3A–B). Body rings. Postcollum constriction modest ( Fig. 1A View FIGURE 1 ). Tegument rough. Front of prozonae delicately al- veolate-areolate. Posterior parts of prozonae with fine longitudinal striations separated by smooth areas. Metazonae with engraved reticulate pattern ( Fig. 3 View FIGURE 3 A–E). Metatergal crests well-developed ( Figs 2 View FIGURE 2 B–G, 3A–E). Crests divided into two transverse rows of tubercles, carinotaxic formula 2/2+I/i+3/3+I/i+2/2 ( Figs 2 View FIGURE 2 B–D, 3B–D). Ozoporiferous tubercles with rounded tip, larger than other tubercles. Lateral crests rather small, about 1/3 size of ozoporiferous tubercles ( Figs 2 View FIGURE 2 B–D, G, 3B–D, 5D). Midbody rings round in cross-section ( Figs 2G View FIGURE 2 , 5D View FIGURE 5 ). Limbus with two rows of fine and regular denticulation ( Fig. 5 View FIGURE 5 E–F).

Telson. Epiproct simple, with a rounded caudal ridge and a sharp dorsal tooth ( Figs 2 View FIGURE 2 E–F, 3E). Paraprocts convex, polytrichous ( Figs 2F View FIGURE 2 , 3F View FIGURE 3 ). Hypoproct crescent-shaped ( Fig. 3F View FIGURE 3 ).

Walking legs. Slender, slightly longer than body width, with a small accessory claw present at base of claw ( Figs 4 View FIGURE 4 G–H, 5D).

Male sexual characters. Male legs I strongly reduced to two-segmented appendages, with a pair of medial coxosternal hooked processes in contact medially ( Fig. 4B View FIGURE 4 ). Male legs II normal. Penes small ( Fig. 4C View FIGURE 4 ). Male legs III modified, with coxa especially slender and elongated ( Fig. 4D View FIGURE 4 ). Femora VI and VII slightly inflated distoventrally ( Fig. 4 View FIGURE 4 E–F). Anterior gonopods. Coxite shield-like, ridged medially, creating a slight depression in caudal view, with a line of microsetae at the distolateral margin ( Fig. 6A View FIGURE 6 ). Coxite processes slightly flattened, prolonged, axe-shaped, slightly longer than telopodites, with a few long setae at the medial margin ( Fig. 6A View FIGURE 6 ). Telopodites located laterally on coxite, one-segmented, slender, curved, with slight apical indentation distomedially and slightly expanded at base, and with several distal setae and a field of microsetae at base ( Fig. 6A, C View FIGURE 6 ). Posterior gonopods. Coxite with a medial lamelliform lobe and a row of strong, curved setae at mediolateral margin ( Fig. 6B View FIGURE 6 ). Flagella short, incurved and sawtooth-shaped at inner margin, situated at the tip of coxite lobe ( Fig. 6B, D View FIGURE 6 ). Lateral margin of coxite with a field of microsetae ( Fig. 6D, E View FIGURE 6 ).

Vulvae. Simple, medial margin with a slightly laterally extended tip ( Fig. 5C View FIGURE 5 ).

Ecology. These millipedes were found under rocks and rotten logs in a deciduous forest ( Fig. 7 View FIGURE 7 ). Some specimens have been parasitized by ectoparasitic fungi in the order Entomophthorales ( Fig. 2A View FIGURE 2 ), resembling its cavernicolous congener G. latus (see Jiang et al. 2017: fig. 2D).

Distribution. China: Hong Kong and Guangdong (Shenzhen).

GenBank accession numbers. MN905178 View Materials – MN905180 View Materials .

Notes. Our specimens agree with all the characters described for G. formosus in its original description, except the number of body rings and body size. The holotype has 72 body rings (number of podus and apodus rings unknown) and is about 50 mm long, whereas the largest specimen in our collection has 60 body rings (58 podus rings and 2 apodus rings) and is 35 mm long. The type of anamorphosis in Cambalidea was deduced to be euanamorphosis ( Enghoff et al. 1993), that means the cambalids can successively molt in its entire lifetime, and every molt is accompanied by the addition of new body rings and length. Indeed, large intraspecific variation in adult ring number is known in the Cambalidea, with differences of up to 35 rings reported ( Enghoff et al. 1993). Therefore, the holotype having more rings and being longer in body length likely indicates a stadium older than our specimens. Based on the near identical somatic morphology, the very close geographic locality, and the fact that there is no other species reported from this area (or even the whole province), we confidently report our specimens as the species G. formosus .

This species was known only from the original description and a brief redescription based on a female holotype, collected in 1892 ( Pocock 1895, Mauriès 1970). No further specimens have been reported since, until now with the 17 we collected for this study. Here, we have described the male of this species for the first time and solved this 125 years mystery.

The most important feature to distinguish the two groups of Glyphiulus , the G. granulatus group and the G. javanicus group, is the morphology of male legs I ( Golovatch et al. 2012, Jiang et al. 2017). However, lacking information on the male morphology, G. formosus was tentatively assigned to the G. javanicus group based on the similarity to G. mediator Attems, 1938 , in that they share the same carinotaxic patterns ( Mauriès 1970, Golovatch et al. 2007b). Our discovery clearly shows the characters of male legs I, and verifies its current taxonomic placement in the G. javanicus group.

The DNA barcodes of three specimens of G. formosus were successfully obtained, with the final length of 635bp. The pairwise intraspecific distances calculated based on Kimura 2-parameter model were 0% and 1.76%, respectively. The interspecific distances between G. formosus and G. sattaa were 23.98%, and between G. formosus and G. duangdee were 26.42% and 26.65% ( Table 1 View TABLE 1 ).