Abstract
A taxonomic study of the genus Skleroprotopus Attems, 1901 from nine provinces in China was conducted utilizing morphological comparisons and molecular phylogenetic analyses. The results reveal thirteen new species, i.e. Skleroprotopus yutiantianae sp. nov., S. tiankeng sp. nov., S. megistus sp. nov., S. penglai sp. nov., S. longissimus sp. nov., S. genjudi sp. nov., S. laiyuanensis sp. nov., S. longiflagellatus sp. nov., S. change sp. nov., S. ampullaceus sp. nov., S. incisodentatus sp. nov., S. multistriatus sp. nov., and S. conicus sp. nov. This significantly enriches the diversity of Skleroprotopus in China, bringing it to a total of 18 species. With the exception of S. yutiantianae sp. nov., all these species were collected in caves. In terms of their degree of adaptation to the cave environment, the latter six species are presumed troglophiles, while the others are likely troglobites. DNA-barcoding based on the COI mitochondrial gene is documented for the first time in this genus. The specific p-distances between Skleroprotopus species range from 6.6–17.0%, while intraspecific p-distances are only 0.2–1.4%. Additionally, the morphological features of male leg-pair 1, the penis and leg-pair 7 are also discussed.
Keywords: barcoding, cave, diversity, new species, phylogeny
Skleroprotopus tiankeng sp. nov.
Holotype male (SCAU), China, Shaanxi Province, Hanzhong City, Nanzheng District, Cave Xigoutiankeng Dong, ..., 850 m, ....
Diagnosis: Differs from congeners mostly based on the following combination of characters: (1) penis much longer than coxae 2 (Fig. 5I); (2) male leg 7 with a very small coxal process, lower than the telopodite (Fig. 5E); (3) anterior gonopod (Fig. 5G, H) with a large and foot-shaped like coxal process, carrying a broadened membranous lobe, outer margin with a triangular protrusion, and a relatively thick flagellum. — In addition, this new species differs from all other species analyzed in a >10.3% uncorrected p-distance of the COI barcoding gene.
Etymology: The species is named after its type locality that is the Hanzhong sinkhole group, a geological wonder composed of multiple heavenly pits. “Tiankeng” in Chinese “天坑”, a noun in apposition.
Skleroprotopus megistus sp. nov.
Diagnosis: Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 3 of male leg 1 particularly broad and bulging in the middle (Fig. 6E); (2) penis subequal in height to coxae 2 (Fig. 6F); (3) coxal process of male leg 7 very small, lower than the telopodite (Fig. 6D); (4) anterior gonopod with a long coxal process carrying a highly developed, axe-shaped, membranous lobe (Fig. 6I). — In addition, this new species differs from all other species analyzed in a >10.3% uncorrected p-distance of the COI barcoding gene.
Etymology: Latinised Greek “megistus” is meaning “large”. The specific epithet refers to the male leg-pair 1 being particularly large; adjective.
Skleroprotopus change sp. nov.
Holotype male (SCAU), China, Hubei Province, Xianning City, Xian’an District, Chang’e Scenic Park, Cave Feixian Dong, ..., 160 m, ...
Diagnosis: Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 4 of male leg 1 rounded, with a small mesal hump (Fig. 8E); (2) penis slightly longer than male coxae 2 (Fig. 8D); (3) male leg 7 with a very small coxal process and a 4-segmented telopodite (Fig. 8F); (4) anterior gonopod (Fig. 8G, H) with a very long coxal process carrying a somewhat broadened and dentated membranous lobe. — In addition, this new species differs from all other Skleroprotopus species analyzed in uncorrected p-distances ranging from between 6.6% (compared to S. longiflagellatus sp. nov.) and 15.6% (compared to S. longissimus sp. nov.).
Etymology: The specific epithet is primarily derived from its type locality, which is named after Chang’e. She is the fairy of the moon palace in the ancient Chinese mythology. “Change” in Chinese “嫦娥”, a noun in apposition.
Skleroprotopus incisodentatus sp. nov.
Diagnosis: Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 4 of male leg 1 with a small mesal hump (Fig. 13D); (2) penis slightly higher than coxae 2 (Fig. 13C); (3) male leg 7 with a very small coxal process, much lower than telopodite, which is made up of 4 segments and a claw (Fig. 13F); (4) anterior gonopod (Fig. 13E, I) with a very long coxal process carrying a narrow, lower, membranous lobe, distally with a vague indentation. — In addition, this new species differs from all other species analyzed in a >8.0% uncorrected p-distance of the COI barcoding gene.
Etymology: The specific epithet refers to the distally vague indentation of a membranous lobe of anterior gonopod; adjective.
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Rong Chen, Yi Zhao, Sergei Golovatch and Wei-Xin Liu. 2024. Molecular Phylogenetic and Morphological Studies reveal increased Species Diversity in the Millipede Genus Skleroprotopus Attems, 1901 in China (Julida: Mongoliulidae). Arthropod Systematics & Phylogeny. 82: 659-691. DOI: doi.org/10.3897/asp.82.e136751