Research Article |
Corresponding author: Sergei I. Golovatch ( sgolovatch@yandex.ru ) Corresponding author: Wei-Xin Liu ( da2000wei@163.com ) Academic editor: Didier Vanden Spiegel
© 2022 Yi Zhao, Wan-Ru Guo, Sergei I. Golovatch, Wei-Xin Liu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Zhao Y, Guo W-R, Golovatch SI, Liu W-X (2022) Revision of the javanicus species group of the millipede genus Glyphiulus Gervais, 1847, with descriptions of five new species from China (Diplopoda, Spirostreptida, Cambalopsidae). ZooKeys 1108: 89-118. https://doi.org/10.3897/zookeys.1108.85156
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The javanicus-group of Glyphiulus is re-assessed and its Chinese component species are presently divided between the following two newly-circumscribed species groups, i.e. the formosus- and the sinensis-group. The two can be differentiated, based on the diagnostic characters of the first pair of legs in the male. In addition, metatergal crests being complete and the carinotaxy formula on the collum being I–III+P+M are only characteristic of the formosus-group. A molecular phylogeny of the genus, based on DNA sequencing of four gene fragments of four genes, allows for Glyphiulus to be recovered as a monophyletic group, the phylogenetic relationship being ((Clade A, Clade B), Clade C). Molecular evidence is fully congruent with the morphological one. In addition, based on barcoding data, interspecific p-distances between Glyphiulus species amount to 11.2–24.9%, vs. 0–8.2% for intraspecific p-distances. Five new species of Glyphiulus, all cavernicolous, are described from China: G. sinuatoprocessus Zhao & Liu, sp. nov., G. conuliformis Zhao & Liu, sp. nov. (both from Guangdong Province), G. xiniudong Zhao & Liu, sp. nov., G. scutatus Zhao & Liu, sp. nov. and G. portaliformis Zhao & Liu, sp. nov. (all three from Guangxi Zhuang Autonomous Region). The known Chinese species of the formosus-group appear to mainly be confined to the South China region.
Cave, DNA barcoding, new record, new species, phylogeny, taxonomy
Glyphiulus Gervais, 1847 is the largest genus in the millipede family Cambalopsidae, currently comprising 70 species (
The genus Glyphiulus has recently been reviewed and divided into two species groups, based on morphological characteristics alone, namely, the granulatus-group and the javanicus-group (
There are presently 103 gene sequences related to Cambalopsidae species that can be found in NCBI. COI and 28S gene fragments used in studies on the genera Trachyjulus Peters, 1864, Glyphiulus and Plusioglyphiulus Silvestri, 1923 have demonstrated the genus Trachyjulus to be monophyletic (
China currently supports the largest number of Glyphiulus species in the world, with 46 known species which are mainly distributed in South China’s karsts (
After many years of investigation and sampling across southern China, the authors of the present paper have found out that the Chinese species from the javanicus-group could further be subdivided into two reliable groups, namely, the formosus- and the sinensis-group, based both on morphological and molecular evidence. However, the phylogenetic relationship between the formosus-, granulatus- and sinensis-group seems to be unstable. To substantiate the above new information, the present paper puts on record not only five new species, but it also adds new records for two previously-described species of Glyphiulus from caves in southern China. Besides this, a key to all 14 species of the formosus-group of Glyphiulus known from China is given and their distributions are mapped.
The material underlying the present study was collected by hand from several caves in southern China and preserved in 95% ethanol. The holotypes and most of the paratypes are deposited in the Zoological Collection of the South China Agricultural University (
Genomic DNA was extracted from legs and collum tissue of specimen samples with Qiagen DNeasy Blood and Tissue kit following the manufacturer’s extraction protocol. Partial sequences of two mitochondrial genes (COI and 16S) and two nuclear genes (18S and 28S) were amplified and sequenced. The PCR amplification was performed using a T100 thermal cycler (BIO-RAD) with a final reaction volume of 25 μl. Raw sequences were edited and assembled using SeqMan Pro software (Lasergene v. 7.1; DNA Star, Inc., Madison, Wis., USA).
Protein-coding gene sequences (COI) were aligned using the codon-aware programme MACSE v. 2.03 (
The analysis involved 37 Glyphiulus, two Plusioglyphiulus and five Trachyjulus COI sequences (18 new sequences and 26 from GenBank). Codon positions included were 1st+2nd+3rd. All positions containing ‘N’s were removed for each sequence pair. Uncorrected p-distances of COI markers were calculated using MEGA X (
The final aligned dataset included 28 sequences, each with 657 bp of COI (one is not available for SCAUG32), 481 bp of 16S rRNA, 627 bp of 18S rRNA and 1182 bp of 28S rRNA. The combined analysis after these exclusions consisted of 2947 positions. Maximum Likelihood (ML) and Bayesian Inference (BI) analyses were executed by PhyloSuite v.1.2.2 (
All analysed species, voucher numbers/taxonomy ID, and Genbank accession numbers are listed in Table
List of the species used for molecular phylogenetic analyses and their relevant information. *: new sequence; /: absent.
Voucher number | Species | GenBank accession numbers | |||
---|---|---|---|---|---|
COI | 16S | 18S | 28S | ||
SCAUG33* | Glyphiulus sp. 1 | ON255879 | ON617345 | ON263093 | ON263226 |
SCAUWL49* | Glyphiulus sp. 1 | ON255892 | ON617360 | ON263096 | ON263229 |
SCAUWL20* | Glyphiulus sp. 2 | ON256155 | ON617353 | ON263101 | ON263239 |
SCAUG32* | Glyphiulus zorzini | / | ON263092 | ON263225 | ON263092 |
SCAUWL23* | Glyphiulus zorzini | ON255887 | ON263095 | ON263228 | ON263095 |
SCAUG39* | Glyphiulus sp. 3 | ON255880 | ON263094 | ON263227 | ON263094 |
IBGASJXK051 | Glyphiulus guangnanensis | MN725096 | MN733292 | MN733302 | MN733282 |
SCAUWL38* | Glyphiulus impletus | ON255889 | ON617357 | ON263088 | ON263235 |
SCAUWL39* | Glyphiulus impletus | ON255890 | ON617358 | ON263090 | ON263236 |
IBGASJXK002 | Glyphiulus impletus | MN725095 | MN733291 | MN733301 | MN733281 |
SCAUG78* | Glyphiulus xiniudong Zhao & Liu, sp. nov. | ON255885 | ON617351 | ON263085 | ON263232 |
SCAUWL37* | Glyphiulus calceus | ON255888 | ON617356 | ON263089 | ON263234 |
IBGASJXK061 | Glyphiulus calceus | MN725098 | MN733294 | MN733304 | MN733284 |
SCAUG72* | Glyphiulus scutatus Zhao & Liu, sp. nov. | ON255884 | ON617350 | ON263084 | ON263231 |
SCAUWL30* | Glyphiulus scutatus Zhao & Liu, sp. nov. | ON256153 | ON617355 | ON263087 | ON263238 |
IBGASJXK059 | Glyphiulus foetidus | MN725097 | MN733293 | MN733303 | MN733283 |
SCAUWL40* | Glyphiulus portaliformis Zhao & Liu, sp. nov. | ON255891 | ON617359 | ON263091 | ON263237 |
JXK275 | Glyphiulus sinuatoprocessus Zhao & Liu, sp. nov. | OM746179 | / | / | / |
SCAUWL02* | Glyphiulus sinuatoprocessus Zhao & Liu, sp. nov. | ON255886 | ON617352 | ON263086 | ON263233 |
SCAUG24* | Glyphiulus conuliformis Zhao & Liu, sp. nov. | ON255878 | ON617343 | ON263083 | ON263230 |
SCAUG15* | Glyphiulus deharvengi | ON255877 | ON617342 | ON263097 | ON263221 |
IBGASJXK310 | Glyphiulus deharvengi | MN725104 | MN733300 | MN733310 | MN733290 |
IBGASJXK072 | Glyphiulus quadrohamatus | MN725099 | MN733295 | MN733305 | MN733285 |
IBGASJXK196 | Glyphiulus granulatus | MN725102 | MN733298 | MN733308 | MN733288 |
SCAUG50* | Glyphiulus proximus | ON255881 | ON617347 | ON263098 | ON263222 |
SCAUG61* | Glyphiulus proximus | ON255882 | ON617348 | ON263099 | ON263223 |
SCAUG62* | Glyphiulus speobius | ON255883 | ON617349 | ON263100 | ON263224 |
CAM022 | Glyphiulus duangdee | MN893779 | / | / | / |
CAM030 | Glyphiulus sattaa | MN893778 | / | / | / |
JXK282 | Glyphiulus formosus | MN905180 | / | / | / |
JXK375 | Glyphiulus fortis | OM746180 | / | / | / |
JXK376 | Glyphiulus fortis | OM746181 | / | / | / |
JXK377 | Glyphiulus fortis | OM746182 | / | / | / |
XK046 | Glyphiulus hainanensis | OM746174 | / | / | / |
XK047 | Glyphiulus hainanensis | OM746175 | / | / | / |
XK048 | Glyphiulus hainanensis | OM746176 | / | / | / |
XK049 | Glyphiulus hainanensis | OM746177 | / | / | / |
XK050 | Glyphiulus hainanensis | OM746178 | / | / | / |
IBGAS JXK517 | Cambala annulata | MT683305 | MT676457 | MT676456 | MT676769 |
IBGAS JXK165 | Hypocambala zizhongi | MN725101 | MN733297 | MN733307 | MN733287 |
CAM031 | Plusioglyphiulus erawan | MN893780 | / | / | / |
CAM021 | Plusioglyphiulus saksit | MN893781 | / | / | / |
CAM059 | Trachyjulus bifidus | MN893771 | / | / | / |
CAM061 | Trachyjulus bifidus | MN893772 | / | / | / |
CAM027 | Trachyjulus phylloides | MN893773 | / | / | / |
CAM079 | Trachyjulus unciger | MN893774 | / | / | / |
CAM070 | Trachyjulus magnus | MN893775 | / | / | / |
The Chinese Glyphiulus species could be divided into three morphologically distinct species groups, mainly based on the structure of male legs 1 (Fig.
Species of the formosus-group are also distinguished by the following characteristics (Fig.
The number of base differences per site between sequences (absolute p-distance) is shown in Suppl. material
Amongst the Glyphiulus species concerned, G. foetidus showed the highest divergence from the other Glyphiulus species, ranging from 14.4–24.9%. The lowest divergence was 11.2% between Glyphiulus sp.1 SCAUG33, SCAUWL49 and G. Glyphiulus sp. 2 SCAUWL20.
The intraspecific divergence of Glyphiulus species was found to range from 0.0–8.2%. Intraspecific distances in our dataset between individuals of G. impletus vary 2.4–8.2%, 2.1% in G. calceus, 0.0–3.3% in G. hainanensis and 6.6% in G. scutatus Zhao & Liu, sp. nov.
As the phylogenetic tree estimated by both the Maximum Likelihood (ML) and Bayesian Inference (BI) analyses revealed equivalent topologies, we only present the BI tree here (Fig.
Within Clade A, almost all internal nodes were strongly supported: 0.54–1 bpp for BI and 51–100% bootstrap values for ML. Glyphiulus foetidus and three new species (G. portaliformis Zhao & Liu, sp. nov., G. sinuatoprocessus Zhao & Liu, sp. nov. and G. conuliformis Zhao & Liu, sp. nov.) found their places in the basal part of the tree, followed by G. scutatus Zhao & Liu, sp. nov. and a sister clade of G. xiniudong Zhao & Liu, sp. nov., G. calceus and G. impletus (Fig.
In the single gene (COI) tree from the ML analysis, Trachyjulus species served as an outgroup and were clearly prioritised (Fig.
Molecular evidence is thereby fully congruent with the morphological one.
Family Cambalopsidae Cook, 1895
Holotype
♂ (
To emphasise the apicomesal process of the anterior gonopod coxite being hook-shaped.
Differs from congeners of the formosus-group by the anterior gonopod showing a high and digitiform process, in which the tip is hook-shaped, coupled with a short, distally pectinate flagellum of the posterior gonopod. Based on molecular evidence, G. sinuatoprocessus Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a > 16.1% uncorrected p-distance of the COI barcoding gene.
Length ca. 33.0–42.0 (♂) or 45.0–50.0 mm (♀), mid-body rings round in cross-section, their width and height similar, 2.2–2.3 mm (♂) or 2.5–2.8 mm (♀). Body with 52–65 (♂) or 70–76 (♀) podous + 1–4 apodous rings + telson. Colouration orange-brownish to brownish, anterior part of body much darker in alcohol, red-brownish (Fig.
Pictures of live animals A G. sinuatoprocessus Zhao & Liu, sp. nov. from Cave Niubi Yan B G. scutatus Zhao & Liu, sp. nov. from Cave Bianfu Dong C G. portaliformis Zhao & Liu, sp. nov. from Cave Baiyan Dong D G. xiniudong Zhao & Liu, sp. nov. from Cave Xiniu Dong E G. conuliformis Zhao & Liu, sp. nov. from Cave Yanzi Dong.
Head
surface smooth (Fig.
Collum
: crests complete and evident; carinotaxy formula I–III+P+M (Fig.
Glyphiulus sinuatoprocessus Zhao & Liu, sp. nov., ♂ paratype A rings 2–4, dorsal view B, E mid-body rings, dorsal and lateral views, respectively C posterior body rings, dorsal view D rings 2–5, sublateral view F cross-section of a mid-body ring, caudal view. Scale bars: 1 mm. Abbreviation: pf: pleural flap.
Glyphiulus sinuatoprocessus Zhao & Liu, sp. nov., ♂ paratype A head, collum and antenna B gnathochilarium C penes D leg 1, frontal view E leg 3, frontal view F mid-leg G ♀ paratype, vulvae H anterior gonopods, caudal view I posterior gonopod, caudal view J flagellum. Scale bars: 0.5 mm (A, B), 0.2 mm, (C–I), 0.1 mm (J).
Epiproct
simple, very narrow, caudal edge uneven, with a strong central tubercle dorsally (Fig.
Legs
slender, about 1.2 times as long as mid-body height; claw with a small accessory spine at base, about 1/3 as long as claw (Fig.
Anterior gonopods
(Fig.
Posterior gonopods
(Fig.
Vulvae
very simple, bare, modestly emarginate medially (Fig.
In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most. In the Guangdong Province and in Hong Kong, only G. formosus and G. granulatus have been recorded as yet.
Holotype
♂ (
To emphasise the metatergal anterior tubercles being very sharp and coniform.
Differs from congeners of the formosus-group by the conical shape of the anterior tubercles of metaterga and by the first segment of the telopodite being significantly enlarged in ♂ legs 1, combined with the anterior gonopod process being slender, finger-shaped and curved inwards distally. Based on molecular evidence, G. conuliformis Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a > 17.0% uncorrected p-distance of the COI barcoding gene.
Length ca. 32.5–37.0 (♂) or 47.0–58.0 mm (♀), mid-body rings round in cross-section, their width and height similar, 1.7–2.0 mm (♂) or 2.2–3.0 mm (♀). Body with 48–53 (♂) or 57–67 (♀) podous + 2–4 apodous rings + telson. Colouration dark brownish, head and legs yellowish (Fig.
Head
surface smooth. Labrum with four teeth anteromedially (Fig.
Collum
: crests complete and evident; carinotaxy formula I–III+P+M (Figs
Glyphiulus conuliformis Zhao & Liu, sp. nov., ♂ paratype A, B anterior body rings, dorsal and lateral views C, D mid-body rings, dorsal and lateral views, respectively E, F posterior body rings, dorsal and ventral views, respectively. Scale bars: 1 mm. Abbreviation: ot: ozoporiferous tubercle.
Epiproct
simple, caudal edge with a very low central protrusion, dorsally with an obvious sharp tubercle (Fig.
Legs
slender, about 1.3 times as long as mid-body height; claw with a small accessory spine at base, about 1/6 as long as claw (Fig.
Glyphiulus conuliformis Zhao & Liu, sp. nov., ♂ paratype A head and collum B right antenna, oral view C gnathochilarium D mid-leg and claw E leg 3, caudal view F leg 1, frontal view G ♀ paratype, vulvae H penes I anterior gonopods, caudal view J, K posterior gonopods, frontal and caudal views, respectively. Scale bars: 0.5 mm (A–E), 0.2 mm (F–K).
Anterior gonopods
(Fig.
Posterior gonopods
(Figs
Vulvae
very simple, bare, M-shaped (Fig.
In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.
Holotype
♂ (
To emphasise the provenance of this species from the “Xiniu” Cave, in Chinese meaning “rhinoceros”; noun in apposition.
Differs from congeners of the formosus-group by the metazonae with an obvious, corrugate, carved texture and by the leg claw with a rather large accessory spine, coupled with a long subtriangular coxosternum of the anterior gonopod, the latter process being narrow and digitiform. Based on molecular evidence, G. xiniudong Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a > 14.7% uncorrected p-distance of the COI barcoding gene.
Length ca. 28.0–31.0 (♂) or 26.0–41.0 mm (♀), mid-body rings round in cross-section, their width and height similar, 1.1–1.3 (♂) or 1.2–1.8 mm (♀). Body with 42–54 (♂) or 45–64 (♀) podous + 0–3 apodous rings + telson. Colouration purple-brownish, legs almost transparent (Fig.
Head
surface smooth. Labrum with four teeth anteromedially. Ocellaria blackish, with 9–13 ommatidia arranged in 1–2 irregular linear rows (Figs
Glyphiulus xiniudong Zhao & Liu, sp. nov., ♂ paratype A head and collum B gnathochilarium and left antenna C mid-body leg and claw D leg 1, frontal view E penes F ♀ paratype, vulvae G anterior gonopods, caudal view H, J posterior gonopod, frontal view I, K posterior gonopod, caudal view. Scale bars: 0.5 mm (A, B), 0.2 mm (C–I), 0.1 mm (J, K).
Collum
: crests complete and evident; carinotaxy formula I–III+P+M (Figs
Epiproct
simple, caudal edge uneven, with an obvious central tubercle dorsally (Fig.
Legs
short, about as long as mid-body height; claw with a relatively large accessory spine at base, about half as long as claw (Fig.
Anterior gonopods
(Fig.
Posterior gonopods
(Figs
Vulvae
very simple, bare, modestly emarginate medially (Fig.
In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.
Holotype
♂ (
To emphasise the anterior gonopod showing a scalloped and shield-shaped coxosternum.
Differs from congeners of the formosus-group by both ♂ femora 6 and 7 being slightly inflated and the anterior gonopod without apicomesal process, as well as the posterior gonopod with less than ten microspinules. Based on molecular evidence, G. scutatus Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a > 15.8% uncorrected p-distance of the COI barcoding gene.
Length of both sexes ca. 25.0–41.0 mm, mid-body rings round in cross-section, their width and height similar, 1.3–1.8 (♂) or 1.8–2.0 mm (♀). Body with 55–68 podous + 1–4 apodous rings + telson. Colouration purple-brownish to dark brownish, legs light brownish to almost transparent (Fig.
Head
surface smooth. Labrum with four teeth anteromedially (Fig.
Glyphiulus scutatus Zhao & Liu, sp. nov., ♂ paratype from Cave Napang Dong A gnathochilarium and right antenna B antenna tip C leg 3, frontal view D leg 1, frontal view E ♀ paratype, vulvae F penes G, J posterior gonopod, frontal and caudal views, respectively H mid-body leg and claw I anterior gonopods, caudal view. Scale bars: 0.5 mm (A, H), 0.2 mm (B–E), 0.1 mm (F, G, I, J).
Collum
: crests complete and evident; carinotaxy formula I–III+P+M (Figs
Epiproct
simple, very narrow, caudal edge uneven, with a clear central tubercle dorsally (Fig.
Legs
slender, about 1.1–1.3 times as long as mid-body height; claw with a small accessory spine at base, about ¼ as long as claw (Fig.
Anterior gonopods
(Fig.
Posterior gonopods
(Figs
Vulvae
very simple, bare, rather faintly emarginate medially (Fig.
In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.
Holotype
♂ (
To emphasise the coxosternum of the anterior gonopods being portal-shaped.
Differs from congeners of the formosus-group by the epiproct showing a small caudal protrusion and the anterior gonopods being portal-shaped, combined with a foliate flagellum of the posterior gonopod. Based on molecular evidence, G. portaliformis Zhao & Liu, sp. nov. Differs from all other Glyphiulus species analysed in a > 14.4% uncorrected p-distance of the COI barcoding gene.
Length of both sexes ca. 41.0–56.0 mm, mid-body rings round in cross-section, their width and height similar, 2.2–3.0 mm. Body with 55–67 podous + 1 apodous ring + telson. Colouration brownish, legs almost transparent (Fig.
Head
surface smooth. Labrum with 4 teeth anteromedially (Fig.
Glyphiulus portaliformis Zhao & Liu, sp. nov., ♂ paratype A gnathochilarium and left antenna B head and collum C penes D mid-leg and claw E leg 3, caudal view F leg 1, frontal view G ♀ paratype, vulvae H anterior gonopods, caudal view I, J posterior gonopod, caudal and frontal views, respectively. Scale bars: 0.5 mm (A, B, D, E), 0.2 mm (C, F–J).
Collum
: crests complete and evident; carinotaxy formula I–III+P+M (Figs
Epiproct
simple, caudal edge with a central conical protrusion and dorsally with a strong central rounded tubercle (Fig.
Legs
slender, about 1.1 times as long as mid-body height; claw with a small accessory spine at base, about 1/5 as long as claw (Fig.
Anterior gonopods
(Fig.
Posterior gonopods
(Figs
Vulvae
very simple, bare, faintly emarginate medially (Fig.
In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.
Glyphiulus calceus Jiang, Guo, Chen & Xie, 2018: 162.
4 ♂, 7 ♀ (
This species has been described from the Cave Xianren Dong, Bala Town, Tian’e County, Guangxi, China. The new samples were collected from a cave in the neighbouring county, both being located close geographically (Fig.
A distribution map of the Glyphiulus formosus species group in China. 1 G. recticullus 2 G. foetidus 3 G. impletus 4 G. calceus 5 G. fortis 6 G. portaliformis Zhao & Liu, sp. nov. 7 G. pulcher 8 G. scutatus Zhao & Liu, sp. nov. 9 G. echinoides 10 G. xiniudong Zhao & Liu, sp. nov. 11 G. sinuatoprocessus Zhao & Liu, sp. nov. 12 G. conuliformis Zhao & Liu, sp. nov. 13 G. formosus 14 G. hainanensis. Abbreviations: FJ: Fujian, HN: Hainan, HuN: Hunan, GD: Guangdong, GX: Guangxi, GZ: Guizhou, ZJ: Zhejiang.
Glyphiulus impletus Jiang, Guo, Chen & Xie, 2018: 171.
9 ♂ (
This species has been found to have a relatively wide distribution in Guangxi, involving the Lingyun, Fengshan, Nandan and Donglan Counties. The new samples add only the records of two cave collections (Fig.
1 | Anterior gonopod with a scalloped and shield-shaped coxosternum (Fig. |
2 |
– | Anterior gonopod coxosternum not fan-shaped, but with a high apicomesal process of varying shapes (Figs |
6 |
2 | ♂ leg 1 with a 1-segmented telopodite | G. pulcher |
– | ♂ leg 1 with a 2-segmented telopodite (Fig. |
3 |
3 | Collum quadrate; telopodite of ♂ leg 1 with a claw | G. recticullus |
– | Collum not quadrate; telopodite of ♂ leg 1 without a claw | 4 |
4 | Neither ♂ femora 6 nor 7 inflated; anterior gonopod coxosternum lower than telopodite | G . echinoides |
– | Both ♂ femora 6 and 7 inflated; anterior gonopod coxosternum higher than telopodite | 5 |
5 | Anterior gonopod coxosternum with 14–15 microsetae along lateral margin; flagellum of posterior gonopod incurved and sawtooth-shaped at inner margin | G. formosus |
– | Anterior gonopod coxosternum with 6–8 microsetae near lateral corner; flagellum of posterior gonopod spike-like (Fig. |
G. scutatus Zhao & Liu, sp. nov. |
6 | Both ♂ femora 6 and 7 inflated, with a small tubercle distoventrally | G. hainanensis |
– | Both ♂ femora 6 and 7 normal, not modified | 7 |
7 | Metazonae with an obvious, corrugate, carved texture (Figs |
8 |
– | Metazonae relatively smooth, not so markedly carved (Figs |
9 |
8 | Apicomesal process of anterior gonopod coxite narrow and digitiform (Fig. |
G. xiniudong Zhao & Liu, sp. nov. |
– | Apicomesal process of anterior gonopod coxite subtriangular (Fig. |
G. portaliformis Zhao & Liu, sp. nov. |
9 | Metatergal anterior tubercles coniform, unusually sharp (Fig. |
G. conuliformis Zhao & Liu, sp. nov. |
– | Metatergal anterior tubercles mostly well-rounded | 10 |
10 | Flagellum of posterior gonopod pectinate distally, with several branches at inner margin | 11 |
– | Flagellum of posterior gonopod broad and flat, finely serrate distally at inner margin | 12 |
11 | Apicomesal process of anterior gonopod coxite digitiform, tip narrow and hook-shaped (Fig. |
G. sinuatoprocessus Zhao & Liu, sp. nov. |
– | Apicomesal process of anterior gonopod coxite subtriangular, tip not hook-shaped | G. foetidus |
12 | Posterior gonopod coxite with a long apicolateral seta | G. calceus |
– | Posterior gonopod coxite without a long apicolateral seta | 13 |
13 | Apicomesal process of anterior gonopod coxite very slender, finger-shaped | G. impletus |
– | Apicomesal process of anterior gonopod coxite rather strong, tip rounded | G. fortis |
Morphologically, the Chinese species from the formosus-group can presently be considered as well-defined: (1) male leg 1 with a pair of small, fused, paramedian, subunciform prongs directed forward, flanked by strongly separated, rudimentary, 1- or 2-segmented leg vestiges; and (2) collum’s carinotaxy formula I–III+P+M. However, although G. submediator Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2011, from Vietnam and G. striganovae Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2012, from Borneo, Indonesia, both agree in the above character 1, the carinotaxy formula of the collum in the former species being I–III+4c+5a+pc+ma (
In addition, most species of the Chinese sinensis-group show the distal margin of the anterior gonopod coxosternum clearly concave and arcuate centrally and the posterior gonopod sometimes lacks a flagellum. On the contrary, all members of the formosus-group either have a scalloped and shield-shaped coxosternum or bear a high apicomesal process of the coxite, while their posterior gonopod always has a flagellum. Based on this, the relationship between the formosus-group and the granulatus-group may be considered closer from the perspective of the anterior and posterior gonopod structure.
In the single-gene COI phylogenetic tree, the genus Plusioglyphiulus may be speculated as being more closely related to Glyphiulus than to Trachyjulus, because its two species are clustered together with Glyphiulus clade BA and clade BB.
In our study, Glyphiulus proves to be a monophyletic taxon, based on both morphological and molecular phylogenetic evidence. It can presently be divided into three clades, the relationship between them being ((Clade A, Clade B), Clade C), albeit none has gained strong support yet. Therefore, in order to fully verify its reliability, a larger number of samples and a greater amount of information are needed to promote further advance in the study of Cambalopsidae, Glyphiulus included.
Most of the Glyphiulus species presently known to occur in China appear to largely be confined to the southern parts of the country. Moreover, most of them have been found in caves. Based on the current distribution map (Fig.
We would like to express our sincere gratitude to the caving team of
Table S1
Data type: Uncorrected p-distances
Explanation note: Uncorrected p-distances for the 657 bp barcoding of the COI gene as between Glyphiulus and some related Cambalosidae taxa.