Weixin Liu

Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda)

Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life.

Three new cavernicolous species of dragon millipedes, genus Desmoxytes Chamberlin, 1923, from southern China, with notes on a formal congener from the Philippines (Diplopoda, Polydesmida, Paradoxosomatidae).

Abstract The large Southeast Asian genus Desmoxytes is slightly rediagnosed. A number of troglomorphic, most likely troglobitic, species occur in southern China. A key is provided to all 10 Desmoxytes spp. currently known from China, including three new presumed troglobites: Desmoxytes eupterygota sp. n. from Hunan Province, as well as Desmoxytes spinissima sp. n. and Desmoxytes lui sp. n. from Guangxi Province. “Desmoxytes” philippina Nguyen Duc & Sierwald, 2010, from the Philippines, is formally removed from Desmoxytes, but not assigned to another genus. It probably belongs in a new genus in the subfamily Australiosomatinae, tribe Antichiropodini, close to the Bornean Euphyodesmus Attems, 1931 and Borneochiropus Golovatch, 1996.

A review of the dragon millipede genus Desmoxytes Chamberlin, 1923 in China, with descriptions of four new species (Diplopoda, Polydesmida, Paradoxosomatidae).

Abstract Four new species of Desmoxytes are described from southern China: Desmoxytes lingulata sp. n., Desmoxytes parvula sp. n., and Desmoxytes nodulosa sp. n., from Guangxi Zhuang Autonomous Region, and Desmoxytes getuhensis sp. n. from Guizhou Province. In addition, new records of Desmoxytes scutigeroides Golovatch, Geoffroy & Mauriès, 2010 and Desmoxytes scolopendroides Golovatch, Geoffroy & Mauriès, 2010 are provided, with a modified key to Desmoxytes species currently known to occur in China. Two of the new species, Desmoxytes nodulosa sp. n. and Desmoxytes getuhensis sp. n., seem to be troglobites.

Four new cavernicolous species of the millipede genus Eutrichodesmus Silvestri, 1910 from southern China (Diplopoda: Polydesmida: Haplodesmidae)

Four new species of the large oriental genus Eutrichodesmus Silvestri, 1910 are described from caves in southern China: E. digitatus sp. n. (Guangdong), E. simplex sp. n. (Jiangxi), E. spinatus sp. n. (Hunan) and E. planatus sp. n. (Guangxi).

Contributions to the millipede genus Nepalella Shear, 1979 from China, with four new species and first results on phylogeny based on DNA-barcoding (Diplopoda, Chordeumatida, Megalotylidae)

Four new species of the chordeumatidan millipede genus Nepalella Shear, 1979, family Megalotylidae, are described from caves in southern China: N. troglodytes sp. nov., N. lobata sp. nov., N. jinfoshan sp. nov., and N. wangi sp. nov. Three of them (except N. lobata sp. nov.) are presumed troglobites. Additional locality records of two cave congeners, N. caeca Shear, 1999 and N. grandoides Golovatch, Geoffroy & Mauriès, 2006, are also provided. DNA-barcoding based on the COI mitochondrial gene is documented in this genus and for species of the order Chordeumatida outside Europe for the first time. Interspecific p-distances between Nepalella species amount to 8.5-15.9%, while intraspecific p-distances are 0-6.8%. The species of Nepalella are found to show a surprisingly low genetic distance from the European genus Atractosoma Fanzago, 1876, family Craspedosomatidae Gray in Jones, 1843, potentially based on the very limited number of barcoding sequences of the order Chordeumatida being available.

Six new species of dragon millipedes, genus Desmoxytes Chamberlin, 1923, mostly from caves in China (Diplopoda, Polydesmida, Paradoxosomatidae).

Abstract Six new species of Desmoxytes are described from southern China: Desmoxytes laticollis sp. n., Desmoxytes simplipoda sp. n., and Desmoxytes similis sp. n., all three from caves in Guangdong Province; Desmoxytes phasmoides sp. n. also from a cave, and both epigean Desmoxytes spiniterga sp. n. and Desmoxytes variabilis sp. n., the latter trio from Guangxi Zhuang Autonomous Region. A modified key to all 20 Desmoxytes species currently known to occur in China is given.

Three new cavernicolous species of the millipede genus Trichopeltis Pocock, 1894 from southern China (Diplopoda, Polydesmida, Cryptodesmidae)

Abstract Three new species of Trichopeltis are described from caves in southern China: T. bellus sp. n., T. intricatus sp. n., and T. reflexus sp. n., all presumed troglobites. The former two come from Yunnan Province, the latter one from Hunan Province. An updated key to all eleven currently known species of Trichopeltis is provided.

Four new species of the millipede genus Eutrichodesmus Silvestri, 1910 from Laos, including two with reduced ozopores (Diplopoda, Polydesmida, Haplodesmidae)

Abstract Laos has large areas of primary forest with a largely unexplored fauna. This is evidenced by millipedes, class Diplopoda, with fewer than 60 species being recorded from the country. In the widespread Southeast Asian “Star Millipede” genus Eutrichodesmus Silvestri, 1910 (family Haplodesmidae), only two of 49 recorded species have been found in Laos. Four new species of Star Millipedes are here described from caves in Laos: Eutrichodesmus steineri Liu & Wesener, sp. n., Eutrichodesmus deporatus Liu & Wesener, sp. n., Eutrichodesmus paraster Liu & Wesener, sp. n. and Eutrichodesmus parvus Liu & Wesener, sp. n.. A fifth species, for which only a female is available, remains unnamed. The defensive glands (ozopores) are found to be strongly or entirely suppressed in two of the new species, Eutrichodesmus deporatus Liu & Wesener, sp. n. and Eutrichodesmus paraster Liu & Wesener, sp. n., both troglobionts, which is new to the family. All of the Star Millipedes were collected during Northern Lao-European Cave Project faunal surveys conducted by the Senckenberg Museum, Frankfurt. A key to the six species of Eutrichodesmus currently known to occur in Laos is provided.

A checklist of millipede genus Hyleoglomeris Verhoeff, 1910 in mainland China, with descriptions of seven new species (Diplopoda, Glomerida, Glomeridae)

Seven new cavernicolous species of the millipede genus Hyleoglomeris Verhoeff, 1910 are described and illustrated from karsts in southern China: H. grandis sp. n., H. baxian sp. n. from Guangxi Zhuang Autonomous Region; H. rhinoceros sp. n., H. getuhensis sp. n., H. generalis sp. n., H. variabilis sp. n. and H. multistriata sp. n., from Guizhou Province. All of them are presumed troglobites except for H. multistriata sp. n. which is likely to be a troglophile because of its well pigmented body. A distribution map of Hyleoglomeris in Guizhou and Guangxi is also provided.

Occurrence of the millipede genus Piccola Attems, 1953 in China (Diplopoda: Polydesmida: Paradoxosomatidae)

Piccola golovatchi sp. nov. is described and illustrated. It comes from the limestone cave called Shizikou Dadong, Tianlin County, Guangxi Zhuang Autonomous Region, southern China. This species is considered to be a troglobite, showing a pallid tegument and extremely enlongated antennae and legs. This is the first record of the millipede genus Piccola Attems, 1953 from China.