Hyperglomeris bicaudata Likhitrakarn, 2023

Likhitrakarn, Natdanai, Srisonchai, Ruttapon, Siriwut, Warut, Jirapatrasilp, Parin, Jeratthitikul, Ekgachai, Panha, Somsak & Sutcharit, Chirasak, 2023, Review of the pill millipede genus Hyperglomeris Silvestri, 1917 (Diplopoda, Glomerida, Glomeridae) with description of two new species from Laos, ZooKeys 1163, pp. 177-198 : 177

publication ID

https://dx.doi.org/10.3897/zookeys.1163.103950

publication LSID

lsid:zoobank.org:pub:F9AC8A45-47D2-45D9-BB12-1A3DB16ABCB0

persistent identifier

https://treatment.plazi.org/id/FB13C74A-496A-45F0-BB73-C710A6C5123D

taxon LSID

lsid:zoobank.org:act:FB13C74A-496A-45F0-BB73-C710A6C5123D

treatment provided by

ZooKeys by Pensoft

scientific name

Hyperglomeris bicaudata Likhitrakarn
status

sp. nov.

Hyperglomeris bicaudata Likhitrakarn sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3A, B View Figure 3

Material examined.

Holotype: Laos - Houaphanh • ♂ (CUMZ-GLO006); Viengxay District, Limestone mountain area near Kaysone Phomvihane Cave ; elev. 890 m a.s.l.; 20°20'24"N, 104°13'44"E; 6 Jul. 2014; R. Srisonchai, C. Sutcharit, K. Inkhavilay leg.; CUMZ GoogleMaps ; Paratypes: Laos - Houaphanh • 1 ♀; same collection data as holotype GoogleMaps ; • 3 ♀♀ (CUMZ-GLO004); Viengxay District, Ban Tham Na Tan, Limestone mountain area; elev. 860 m a.s.l.; 20°27'28"N, 104°08'43"E; 5 Jul. 2014; R. Srisonchai, C. Sutcharit, K. Inkhavilay leg.; CUMZ; OQ661871 View Materials GoogleMaps 1 ♂, 2 ♀♀ (CUMZ-GLO007); Viengxay District, Limestone mountain area near vocational-technical school around kilometre 31; elev. 840 m a.s.l.; 20°24'15"N, 104°15'4"E; 6 Jul. 2014; R. Srisonchai, C. Sutcharit, K. Inkhavilay leg.; CUMZ; OQ661872 View Materials GoogleMaps .

Name.

To emphasize the caudal margin of the anal shield being more (♂) or less (♀) strongly bisinuate medially; adjective in feminine gender.

Diagnosis.

Its unique color pattern is similar to that of H. nigra Golovatch, 2017, from Vietnam (Golovatch, 2017), but the two species differ by the thickness of the contrasting paler bands at the lateral and caudal edges of all tergites (ca. 1/3 vs. 1/5 × as high as tergite height), the number of striae at the lateral edge of midbody tergites (2 vs. 3), the number of ommatidia (10+1(2) vs. 8+1), coupled with two tibial processes (one large process and one small cone vs. two small tibial cones), and the caudal edge of the anal shield (two strongly bisinuate medially vs. slightly emarginate medially).

Description.

Body length of stretched holotype 13.2 mm, width 8.3 mm. Body length of stretched paratypes 13.5 mm (♂), 13.5-15.5 mm (♀), width 9.5 (♂), 8.5-9.5 mm (♀).

Coloration of live animals (Fig. 1A-D View Figure 1 ): body blackish, with contrasting pale yellow to orange yellow, rather broad bands at the lateral and caudal edges of all tergites, ca. 1/3 × as high as each tergite height, including collum, thoracic and anal shields. Head and antennae black, only labrum and Tömösváry’s organ yellowish. Venter and legs dark brown to brown with a pale yellowish claw and the posterior part of each tarsus; coloration in alcohol faded after eight years of preservation (Fig. 1E-G View Figure 1 ), body pale black to charcoal, with contrasting pale yellow to whitish bands. Head and antennae grey to blackish. Venter and legs pale brown to brownish.

Labrum sparsely setose (Fig. 1F View Figure 1 ). Gnathochilarium with 2+2 palps of subequal length. Ocular fields whitish, 10+1(2) ommatidia, cornea convex, oval in shape, translucent. Antennae with four evident apical cones, segment 6 ca. 2.1-2.4 × as long as high. Organ of Tömösváry typical, horseshoe-shaped, oblong-oval, elongate, ca. 1.5-1.8 × as long as broad (Fig. 1F View Figure 1 ).

Collum as usual, with two transverse striae (Fig. 1F View Figure 1 ). Thoracic shield with a small hyposchism field not projecting caudad past tergal margin. Striae 4-6, mostly superficial, only lower 3 or 4 lying above schism, one level with schism, remaining 1 or 2 below schism, with 4 and 5 complete, crossing the dorsum (Fig. 1G View Figure 1 ). Terga 3 and 4 rather broadly rounded laterally (Fig. 1G View Figure 1 ). Following terga in front of pygidium faintly concave medially at caudal edge and with two striae starting above lateral edge, sometimes first stria fading away towards midway. Caudal edge of anal shield more (♂, Figs 1C, E, F, G View Figure 1 , 2A View Figure 2 ) or less (♀, Fig. 2B View Figure 2 )) strongly bisinuate medially.

Male legs 17 (Fig. 2C View Figure 2 ) strongly reduced, with a rather high, often irregularly rounded coxal lobe (cxl) and a 4-segmented telopodite.

Male legs 18 (Figs 2D View Figure 2 , 3A, B View Figure 3 ) simple, rather strongly reduced, without any evident outgrowths; syncoxite membranous, on either side with a simple, small, and narrowly ogival syncoxite notch (sn) and a 4-segmented telopodite.

Telopods (= male legs 19) (Fig. 2E-G View Figure 2 ) with a very large, broad and roundly subtrapeziform syncoxital lobe (sl) flanked by two short, spiniform, obliquely truncate, setose syncoxital horns (sh), level with syncoxital lobe (Fig. 2F View Figure 2 ). Telopodite 4-segmented, with a spine apically. Prefemur subellipsoid, with an evident, rather small, distad tapering, tuberculiform, distomesal prefemoral cone (pc) (a reduced trichostele), ca. 1/4-1/5 × as long as femur. The latter in caudal view with a prominent, stout, finger-shaped, distomesal femoral process (fp) devoid of a trichostele, produced apically to ca. 3/4 tibia. Tibia elongate, gently tapering distad and curved apically basad towards process on femur, with an evident, caudad curved, distolateral tibial process (tp) and a small, short and pointed distomesal tibial cone (tc). Tarsus smallest, subcylindrical, moderately sigmoid, strongly curved, narrowly rounded apically.

Remarks.

Unique to this species is that the caudal margin of the anal shield shows two more (♂, Figs 1C, E, F, G View Figure 1 , 2A View Figure 2 ) or less (♀, Fig. 2A View Figure 2 ) pronounced paramedian knobs. That the male is equipped with such modifications is quite usual in various lineages of Glomerida (e.g., Liu and Golovatch 2020), but their presence in the female, albeit not as strongly as in the male, is really striking.

This distinguishing character can be hypothesized as possibly playing an important role in a courtship process or being associated with courtship behavior. Certain male structures dedicated to interactions with females during courtship have often diverged relatively quickly during evolution, causing these features to change into species-specific differences ( Eberhard 2004). Noteworthy examples of such characters are antennae, legs and heads in springtails ( Collembola : Bourletiellidae ) ( Kozlowski and Aoxiang 2006) and stridulation organs in giant pill millipedes (Sphaerotheria) ( Wesener et al. 2011) that may not be involved directly in sperm transfer but are associated with mating behavior. In order to understand the relationship between these types of traits and their function in the glomerids, it is essential to examine the mating behavior of this species.

Kingdom

Animalia

Phylum

Arthropoda

Class

Diplopoda

Order

Glomerida

Family

Glomeridae

Genus

Hyperglomeris