Research Article |
Corresponding author: Chao Jiang ( jiangchao0411@126.com ) Academic editor: Marzio Zapparoli
© 2020 Chao Jiang, Yunjun Bai, Mengxuan Shi, Juan 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:
Jiang C, Bai Y, Shi M, Liu J (2020) Rediscovery and phylogenetic relationships of the scolopendromorph centipede Mimops orientalis Kraepelin, 1903 (Chilopoda): a monotypic species of Mimopidae endemic to China, for more than one century. ZooKeys 932: 75-91. https://doi.org/10.3897/zookeys.932.51461
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Mimops orientalis Kraepelin, 1903 is a monotypic species of Mimopidae endemic to China. The species is known only from a single specimen, the holotype. Little is known about its biology, habitat associations, or phylogenetic relationships. It was rediscovered on Qinling Mountain in Shaanxi and Henan provinces, China, 117 years after its last record. Detailed descriptions and colour photographs of living specimens are provided along with its ecology, updated conservation notes, and data on sexual dimorphism. A genetic analysis (COI, 16S rRNA, and 28S rRNA) was conducted to assess the phylogenetic relationships among Mimopidae, Cryptopidae, Scolopendridae, Scolopocryptopidae, and Plutoniumidae. The results support classifying Mimopidae as a valid family.
morphology, new distribution, Qinling Mountain
Mimops Kraepelin, 1903 is one of the least-known genera of scolopendromorph centipedes. The type species, Mimops orientalis Kraepelin, 1903, described from a single specimen from Shaanxi Province, China, has a single white ocellus on each side of the cephalic plate. Since the original description, the exact type locality of this species has been unknown, and no additional findings of M. orientalis have been reported. The genus Mimops was initially placed in the Cryptopidae and subsequently redescribed by
However, the only material of M. orientalis, the unsexed holotype specimen, did not allow
Throughout 2018 and 2019, we made intensive biodiversity surveys in the Taiping National Forest Park and Longyuwan National Forest Park, China. During this fieldwork, fresh material of M. orientalis was collected at the edge of Qinling Mountain. It is a region that has only few previous surveys for centipedes but has been highlighted as one of 16 biodiversity hotspots (
The studied individuals of Mimops orientalis were collected in Taiping National Forest Park, Shaanxi, China, and Funiushan National Nature Reserve, Henan, China. Other representative samples of Cryptopidae, Scolopendridae, Scolopocryptopidae, and Plutoniumidae were collected more generally in China. During the field study, some individuals were photographed with an Olympus E-M10 II camera to record their living colour pattern. The colour description is based on that of living centipedes. Specimens are deposited in the Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, China (CMMI).
The taxonomic characteristics of the specimens were observed under an Olympus SZ16 stereomicroscope. Multifocus montage images were produced using Helicon Focus 6.7.1 software from a series of source images taken by a Canon 50D digital camera attached to the stereomicroscope. Terminology applied to the external anatomy follows
All newly collected centipede specimens were stored in 75% ethanol. Legs 15 and 17 of the newly collected specimens were removed and stored in 100% ethanol for DNA extraction.
Genomic DNA was extracted from leg tissue using a DNeasy Blood and Tissue Kit (Qiagen, Hilden, Germany). Two fragments of mitochondrial DNA (mtDNA), the encoded parts of the COI and 16S ribosomal RNA genes, and a fragment of 28S nuclear ribosomal RNA were amplified according to previously literature (
Maximum likelihood and Bayesian inference approaches were employed using MEGA X (
Holotype
: China, Süd Schensi, August 1903, kept in Zoologisches Institut und Zoologisches Museum der Universität, Hamburg, Germany (
Shaanxi, China. Perhaps referring to Xi’an, Shaanxi, China.
Seven Mimops orientalis specimens were collected near a river in the Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 620–640 m alt.), and another M. orientalis were collected in 2019 from Funiushan National Nature Reserve, Luanchuan, Henan, China. Mimops orientalis (n = 8). CMMI 20190714001, adult, under a stone near a river, Longyuwan National Forest Park, Luanchuan, Henan, China, (33.713N, 111.775E, 1110 m alt.) collected by Mengxuan Shi, on 14 Jul. 2019. CMMI 20190908001, adult male, under a stone near a ditch, Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 630 m alt.), collected by Chao Jiang, on 08 Sept. 2019. CMMI 20190908002, juvenile, under a stone in some brushwood, Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 620 m alt.), collected by Chao Jiang, on 08 Sept. 2019. CMMI 20190908003 and CMMI 20190908004, juvenile, under stones in grass halfway up a steep hill, Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 640 m alt.), collected by Chao Jiang, on 08 Sept 2019. CMMI 20190908005, adult, under a trash bin near the road, Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 626 m alt.), collected by Chao Jiang, on 08 Sept. 2019. CMMI 20190908006, subadult, under a stone near the collection site of specimen CMMI 20190908005, collected by Chao Jiang, on 08 Sept. 2019. CMMI 20190908007, juvenile, under a stone of brushwood, Taiping National Forest Park, Hu county, Shaanxi, China (33.98N, 108.69E, 620 m alt.), collected by Chao Jiang, on 08 Sept 2019.
Plutoniumidae: Theatops chuanensis Di et al., 2010, CMMI 20190405013, Tianzishan National Reserve, Zhangjiajie, Hunan province, China. CMMI 20190606004, Wen county, Longnan, Gansu province, China.
Cryptopidae: Cryptops sp., CMMI 20190413007, Longjin road, Huoshan county, Liu’an, Anhui province, China.
Scolopendridae: Scolopendra mutilans L. Koch, CMMI 20190331001, Qianfodong National Forest Park, Duodao distinct, Jinmen, Hubei province, China. CMMI 20190702006, Xiangshan, Dinghai distinct, Zhoushan, Zhejiang province, China.
Scolopocryptopidae: Scolopocryptops nigrimaculatus Song, Song & Zhu, 2004, CMMI 20181207002, Jinxi hotel, West Lake, Hangzhou, Zhejiang province, China.
Currently, we have confirmed that M. orientalis occurs on Qinling Mountain (Shaanxi and Henan provinces) and inhabits forests near rivers above 500–1200 m elevation (Fig.
Specimens of M. orientalis were collected from two locations on Qinling Mountain. We captured all of our new material at midday (11:00–13:00), always in forest edges near a river and under microhabitat refuges (rocks, bushes, leaf litter, and garbage). Two adult specimens were hiding under stones coated with moss, and another adult was encountered under some garbage containing rainwater. Most juveniles were encountered under small stones in bushes or moving over leaf litter in a fragmented patch of Liquidambar formosana Hance. Natural vegetation in the surrounding areas is deciduous forest, composed mainly of Juglans regia L., Cotinus coggygria Scop., and L. formosana Hance. Vegetative cover was ornamented by Urtica spp., Viola spp., Cyperus iria L., and Oplismenus undulatifolius (Arduino) Beauv (Figs
Cephalic plate brownish red to orange-red, more deeply coloured in the anterior part. Coxosternites, forcipules, and tergites pale yellow to pale brown, ultimate segment and ultimate legs pale orange. Antennae, all sternites, and dorsal aspects of the legs light yellow. The live colour of a specimen from Shaanxi is slightly different from others. Its ultimate leg prefemur was nearly brown, which is more deeply coloured than that of the femur and tibia. The juvenile individual was uniformly light yellow on the cephalic plate, antennae, tergites, sternites, and all legs (Figs
Adult length 42–56 mm. Cephalic plate smooth, about as long as it is wide, very finely punctate with the posterior margin overlying tergite 1. Cephalic plate lacks paramedian sulci in adults (two sulci in juvenile). A pale area instead of lateral ocelli at the base of each antenna (
Tooth plates are short but wide, ridged and have approximately 25 ridges on each side and a prominent seta behind the anterior margin (Fig.
Tergite 1 with anterior transverse (ring) sulcus (Fig.
All legs with two-segmented tarsi. Two tibial spurs on legs 1–18, 19 with one, 20 without. Legs 1–20 each with two tarsal spurs (Fig.
10 Coxosternite and forcipules of Mimops orientalis 11–15 Trunk segment features of Mimops orientalis. 11 Tergites 11–13, showing paramedian sutures and spiracle 12 sternites 5–7, showing sutures 13 spiracle on segment 5 14 ventral view of legs 5–7 (right) 15 dorsal view of leg 3 (right).
Tergite 21 with small spines and a narrow posterior median depression (Fig.
Genital segments well developed, reaching the distance between the posterior margin of sternite 21 and the distal part of the coxopleural process. In males, sternite of genital segment 1 round, with short setae ventrally, genital segment 2 round and convex, also with short setae ventrally. Penis columnar, with long setae dorsally. Gonopod present in males with seven or eight long setae (Fig.
Although this species was found from two localities separated by 400 km, there is not yet enough information about the distribution, abundance, or threats to this species, and so further surveys are needed; we consider it Data Deficient for now (IUCN 2020).
We obtained 887 bp sequences of COI, 537 bp of 16S and 992 bp of 28S of M. orientalis. The complete matrix included sequences from 44 centipede species (Table
The results of the phylogenetic analysis are presented in Figures
Phylogenetic trees obtained from the COI, 16S, and 28S sequences 21 ML tree from the analysis of the concatenated genes 22 tree from the Bayesian analysis of all genes combined. Numbers at the nodes are bootstrap percentages obtained from the ML analyses and posterior probabilities obtained from BI.
List of the 44 selected sequences obtained from this study GenBank nucleotide database used in phylogenetic analyses.
Taxonomy | Species | Voucher number | Taxon locality | GenBank accession number | Reference | ||
---|---|---|---|---|---|---|---|
COI | 16S | 28S | |||||
Mimopidae | Mimops orientalis | CMMI 20190908002 | Shaanxi, China | MT093838 | MT084401 | MT084368 | This study |
Mimops orientalis | CMMI 20190908003 | Shaanxi, China | MT093839 | MT084402 | MT084369 | This study | |
Mimops orientalis | CMMI 20190908006 | Shaanxi, China | MT093840 | MT084403 | MT084370 | This study | |
Cryptopidae | Cryptops (Cryptops) trisulcatus | Italy | HQ402544 | HQ402493 | AF000783 | 1 | |
Cryptops (Cryptops) doriae | IZ-130578 | Thailand | KF676500 | KF676458 | KF676354 | 1 | |
Cryptops (Trigonocryptops) galatheae | IZ-130581 | Argentina | KF676501 | KF676459 | KF676355 | 1 | |
Cryptops (Trigonocryptops) spinipes | AM KS 58457 | Australia | AY288743 | AY288724 | AY288709 | 1 | |
Cryptops (Paracryptops) indicus | IZ-130608 | Vietnam | KF676505 | KF676463 | KF676357 | 1 | |
Cryptops sp. | CMMI 20190413007 | Liuan, China | MT093841 | MT084404 | MT084371 | This study | |
Plutoniumidae | Theatops erythrocephalus | IZ-130611 | Portugal | HM453313 | HM453222 | AF000784 | 1 |
Theatops posticus | IZ-131448 | USA | AY288746 | AY288727 | – | 1 | |
Theatops chuanensis | CMMI 20190405013 | Hunan, China | MT093842 | MT084405 | MT084372 | This study | |
Theatops chuanensis | CMMI 20190606004 | Gansu, China | MT093843 | MT084406 | MT084373 | This study | |
Plutonium zwierleini | PD-S-0221 | Italy | LN890292 | LN890289 | LN890291 | ||
Scolopocryptopidae | Newportia divergens | IZ-130770 | Mexico | JX422667 | JX422690 | KF676359 | 1 |
Newportia adisi | IZ-130770 | Brazil | KF676506 | KF676465 | JX422586 | 1 | |
Scolopocryptops nigridius | IZ-130806 | USA | JX422680 | JX422704 | JX422594 | 1 | |
Scolopocryptops rubiginosus | IZ-130823 | Taiwan | JX422682 | JX422706 | – | 1 | |
Scolopocryptops nigrimaculatus | CMMI 20181207002 | Hangzhou, China | MT093844 | MT084407 | – | This study | |
Scolopocryptops sexspinosus | IZ-131450 | USA | AY288745 | AY288726 | AY288710 | 1 | |
Scolopendridae | Scolopendra subspinipes | IZC 00146521 | Martinique | HQ402554 | HQ402502 | HQ402538 | 1 |
Scolopendra mutilans | CMMI 20190331001 | Hubei, China | MT093845 | MT084408 | MT084374 | This study | |
Scolopendra mutilans | CMMI 20190702006 | Zhejiang, China | MT093846 | MT084409 | MT084375 | This study | |
Scolopendra viridis | IZ-130727 | USA | DQ201431 | DQ201425 | DQ222134 | 1 | |
Cormocephalus hartmeyeri | IZ-130632 | Australia | KF676531 | KF676491 | KF676391 | 1 | |
Cormocephalus monteithi | IZ-130638 | Australia | DQ201430 | AF370861 | AF173280 | 1 | |
Cormocephalus pseudopunctatus | IZ-130646 | South Africa | KF676534 | KF676493 | KF676398 | 1 | |
Hemiscolopendra marginata | IZ-130659 | USA | HQ402548 | HQ402496 | – | 1 | |
Scolopendridae | Arthrorhabdus formosus | AMNH LP6656 | South Africa | HQ402539 | HQ402488 | HQ402522 | 1 |
Campylostigmus orientalis | IZ-130623 | New Caledonia | HQ402542 | HQ402491 | KF676404 | 1 | |
Notiasemus glauerti | WAMT124343 | Australia | KF676539 | KF676498 | KF676405 | 1 | |
Otostigmus astenus | IZ-130669 | Fiji | HM453312 | HM453221 | HQ402532 | 1 | |
Otostigmus politus politus | IZ-130674 | China | KF676512 | KF676470 | KF676368 | 1 | |
Otostigmus scaber | IZ-130664 | Taiwan | KF676513 | KF676471 | KF676369 | 1 | |
Digitipes barnabasi | CES 091355 | India | JX531905 | JX531775 | JX531826 | 2 | |
Digitipes coonoorensis | CES 08960 | India | JX531850 | JX531720 | JX531793 | 2 | |
Ethmostigmus curtipes | WAM115537 | Australia | KF676515 | KF676474 | KF676372 | 1 | |
Ethmostigmus rubripes rubripes | IZ130653 | Australia | KF676542 | KF676475 | KF676373 | 1 | |
Rhysida afra | IZ-130677 | South Africa | HQ402552 | HQ402500 | HQ402536 | 1 | |
Rhysida polyacantha | IZ-130665 | Australia | KF676518 | KF676476 | KF676376 | 1 | |
Lithobiomorpha | Lithobius forficatus | – | – | AJ270997 | AJ270997 | EF199984 | 3 |
Craterostigmomorpha | Craterostigmus tasmanianus | IZ-132143 | Australia | EU024611 | EU024597 | HM453265 | 1 |
Geophilomorpha | Bothriogaster signata | IZ-131562 | Greece | AY288749 | AY288730 | HM453290 | 1 |
Scutigeromorpha | Scutigera coleoptrata | IZ-130904 | South Africa | DQ222170 | DQ222156 | EF199983 | 1 |
The taxonomic position of Mimops has been controversial for many years. Attems (1930) divided scolopendromorphs into blind scolopendromorphs and ocellate scolopendromorphs, the latter containing only a single family, Scolopendridae, whereas the former includes three eye-less scolopendromorph families (Cryptopidae, Plutoniumidae, and Scolopocryptopidae), hence, the name blind clade. The genus Mimops was first classified into the subfamily Cryptopinae of the family Cryptopidae by Attems (1930) and then removed from Cryptopinae in a cladistic analysis by
Mimops orientalis also possesses several unusual characteristics among Plutoniumidae, Cryptopidae, Scolopocryptopidae, and Scolopendridae. It shares many characteristics with scolopendrid centipedes, including a smooth cephalic plate without setae or spines, several glabrous basal antennal articles, the presence of sternite and tergite paramedian sutures, the presence of spines on the prefemora of the ultimate legs, and an anterior transverse sulcus on tergite 1. These characteristics render it similar to Scolopendra species, particularly many New World varieties. However, M. orientalis lacks lateral ocelli and instead possesses a pale area, which is only present in plutoniumids, and the spines on the ultimate legs are very small, which is similar to some Trigonocryptops species, e.g., Cryptops (Trigonocryptops) camoowealensis Edgecombe, 2006. This renders the taxonomic position of Mimops puzzling.
In this study, we confirmed Mimopidae as a valid family based on both morphological and molecular data. We also place Mimops as the basal taxa of scolopendromorphs for the following reasons: 1) M. orientalis is resolved as monophyletic both in maximum likelihood and Bayesian inference analyses under all parameter sets that were explored; 2) the ocelli of Mimops are regressed and have left two pale areas, whereas the outgroups Lithobiomorpha, Scutigeromorpha, and Craterostigmomorpha all have ocelli (or a compound eye with ommatidia in the case of Scutigeromorpha), indicating that ocelli may be a plesiomorphic characteristic; 3) Mimops bears 21 trunk segments, whereas 21 to 23 segments is an unreversed apomorphy of Scolopocryptopidae; 4) the long and acute spines on the forcipular trochanteroprefemoras of Mimops may be a primitive characteristic of trochanteroprefemur process; and 5) the small homologous spines on the ultimate legs, coxopleural process and ultimate sternites seem to be an intermediate state between setae and spines. However, although BI and ML analyses both support the validity of Mimopidae, the precise position of Mimops is not delimited due to the unresolved trichotomy in BI tree. Further research based on complete mitochondrial genome or transcriptomic data may help to clarify phylogenetic relationships among Mimopidae and other families.
The authors sincerely thank Mr Jiazhou Lu for help collecting specimens and taking photographs of living specimens. This work was supported by National Key R & D Program of China (2019YFC1711000) and the Fundamental Research Funds for the Central public welfare research institutes (ZZXT201908).