Research Article |
Corresponding author: Jeremy A. Miller ( jeremy.miller@naturalis.nl ) Academic editor: Charles Haddad
© 2019 Chengcheng Feng, Jeremy A. Miller, Yucheng Lin, Yunfei Shu.
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:
Feng C, Miller JA, Lin Y, Shu Y (2019) Further study of two Chinese cave spiders (Araneae, Mysmenidae), with description of a new genus. ZooKeys 870: 77-100. https://doi.org/10.3897/zookeys.870.35971
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The current paper expands knowledge of two Chinese cave spider species originally described in the genus Maymena Gertsch, 1960: M. paquini Miller, Griswold & Yin, 2009 and M. kehen Miller, Griswold & Yin, 2009. With the exception of these two species, the genus Maymena is endemic to the western hemisphere, and new evidence presented here supports the creation of a new genus for the Chinese species, which we name Yamaneta gen. nov. The male of Y. kehen is described for the first time. Detailed illustrations of the habitus, male palps and epigyne are provided for these two species, as well as descriptions of their webs. DNA sequences are provided for both Yamaneta species. We build on a previously published phylogenetic analysis of Mysmenidae to assess the phylogenetic position of Yamaneta and its relationship to true Maymena.
China, Gaoligong Mountains, Maymena, new genus, phylogeny, symphytognathoids, troglobite
The genus Maymena Gertsch, 1960 was established in the context of a taxonomic paper describing several American spiders of the family Symphytognathidae Hickman, 1931. At that time, the concept of Symphytognathidae was broader than it is today; the taxa described therein are currently distributed among four families (Symphytognathidae, Mysmenidae Petrunkevitch, 1928, Anapidae Simon, 1895 and Theridiosomatidae Simon, 1881). The world’s Symphytognathidae were reviewed and redefined by Forster and Platnick (1977), and several symphytognathid genera were transferred to other families, including Maymena to the Mysmenidae.
In August 2008, students and professors of Sichuan University carried out a collecting survey in the Gaoligong Mountains. Both males and females of Miller et al.’s Chinese Maymena species were collected from their type localities and their web structures were discovered and photographed. In addition to new detailed morphological data and the description of the previously unknown male of M. kehen, multiple individuals of both species were sequenced for five loci. To test the relationships of Chinese Maymena to western Maymena and other Mysmenidae, we added this DNA sequence data to the molecular phylogenetic dataset of
Specimens were acquired by hand from the dark zone of caves and preserved in 95% ethanol. They were examined using a Leica M205 C stereomicroscope. Further details were studied under an Olympus BX43 compound microscope. Male palps and epigynes were examined and photographed after dissection. Epigynes were treated in lactic acid before being embedded in Arabic gum to take the photos of the vulva. To reveal the course of the spermatic ducts, male palps were also clarified using lactic acid and subsequently mounted in Hoyer’s Solution. The left palp was photographed and described. Photos were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels) mounted on an Olympus BX 43 compound microscope. The images were montaged using Helicon Focus 3.10 (
Tissue samples were taken from eight individual specimens of Chinese Maymena representing both known species. Whole genomic DNA was extracted from tissue samples with TIANamp Micro DNA Kit (TIANGEN) following the manufacturer’s protocol for animal tissues. Five gene fragments were amplified in 25μL reactions: mitochondrial large-subunit ribosomal RNA (16S), nuclear small-subunit ribosomal RNA (18S), nuclear large-subunit ribosomal RNA (28S), cytochrome c oxidase subunit I (COI), and histone H3 (H3). Primer pairs and PCR protocols are given in Table
Locus | Annealing temperature/time | Direction | Primer | Sequence 5’→3’ | Reference |
16S | 48.5°/30s | F | LR-J-12864 | CTCCGGTTTGAACTCAGATCA |
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R | LR-J-13360 | GTAAGGCCTGCTCAATGA | This study | ||
45°/30s | F | LR-J-12964 | AACTCAGATCATGTAATAATT | This study | |
R | LR-J-13360 | GTAAGGCCTGCTCAATGA | This study | ||
18S | 54.9°/30s | F | 18S-1F | TACCTGGTTGATCCTGCCAGTAG |
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R | SSU rRNA reverse | GTGGTGCCCTTCCGTCAATT |
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28S | 53.1°/30s | F | 28Sa | GACCCGTCTTGAAACACGGA |
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R | LSUR | GCTACTACCACCAAGATCTGCA |
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COI | 46°/30s | F | LCO1490 | GGTCAACAAATCATAAAGATATTGG |
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R | HCO2198 | TAAACTTCAGGGTGACCAAAAAATCA |
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45°/30s | F | LCO1490 | GGTCAACAAATCATAAAGATATTGG |
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R | C1-N-2191 (Nancy) | CCCGGTAAAATTAAAATATAAACTTC |
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H3 | 46°/30s | F | H3aF | ATGGCTCGTACCAAGCAGACVGC |
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R | H3aR | ATATCCTTRGGCATRATRGTGAC |
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49.4°/30s | F | H3nF | ATGGCTCGTACCAAGCAGAC |
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R | H3nR | ATRTCCTTGGGCATGATTGTTAC |
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Species | Identifier | Sex/Stage | 16S | 18S | 28S | COI | H3 |
Yamaneta kehen | GlgMY14 | Male | MK908789 | MK908805 | MK908797 | MK895530 | MK895538 |
GlgMY14 | Female | MK908790 | MK908806 | MK908798 | MK895531 | MK895539 | |
GlgMY14 | Juvenile | MK908791 | MK908807 | MK908799 | MK895532 | MK895540 | |
GlgMY15 | Male | MK908792 | MK908808 | MK908800 | MK895533 | MK895541 | |
GlgMY15 | Female | MK908793 | MK908809 | MK908801 | MK895534 | MK895542 | |
Yamaneta paquini | GlgMY16 | Male | MK908794 | MK908810 | MK908802 | MK895535 | MK895543 |
GlgMY16 | Female | MK908795 | MK908811 | MK908803 | MK895536 | MK895544 | |
GlgMY16 | Juvenile | MK908796 | MK908812 | MK908804 | MK895537 | MK895545 |
The most recent molecular phylogeny of Mysmenidae was
The most parsimonious tree was found using 1000 replicates of random taxon addition and TBR (Tree-Bisection-Reconnection) branch swapping using MEGA X (
The Bayesian phylogenetic inference was performed using MrBayes version 3.2.6 (
Abbreviations appearing in text and figures are as follows:
ALE anterior lateral eyes
AME anterior median eyes
BC base of cymbium
BH basal haematodocha
CA cymbial apophysis
CD copulatory ducts
CS clasping spine on leg I
Cy cymbium
CyC cymbial conductor
CyFs setae on cymbial fold
E embolus
FD fertilization ducts
PC paracymbium
PLE posterior lateral eyes
PME posterior median eyes
S spermathecae
SD spermatic duct
Sp scape
T tegulum
Ti tibia
TiS setae on palpal tibia
TS tibial spine on leg I
TTr trichobothria on tibia
Institutional acronyms:
NHMSU Natural History Museum of Sichuan University, Chengdu, China
Parsimony analysis of the expanded sequence alignment recovered a single most parsimonious tree (Fig.
Single most parsimonious tree (15922 steps) resulting from the analysis of
After 50,000,000 generations of Bayesian analysis, the average deviation of split frequencies fell below 0.05. The combined effective sample sizes of the two MCMC chains were 7425.9 and 7654.5 (12,520.9 combined), comfortably above the recommended minimum of 200 (
Topology from Bayesian mixed model analysis based on
Monophyly of and relationships between the so-called symphytognathoid families (including Mysmenidae, Anapidae, Theridiosomatidae and Symphytognathidae) are complicated and inconsistent across various analyses. Early attempts based on morphological data (e.g.,
The parsimony and Bayesian phylogenies presented here disagree about outgroup relationships in several important ways, including the monophyly of Anapidae, its relationship to Micropholcommatinae, and the sister clade to Mysmenidae. Such results are not surprising, because previous studies relying on the same limited set of reliable loci have seen similar results for nearly a decade, and also because taxon sampling outside Mysmenidae in this study and its predecessors (
Recent phylogenomic approaches have finally expanded the volume of DNA sequence data used to investigate spider phylogeny (
Maymena paquini Miller, Griswold & Yin, 2009.
Formed from Yama, the figure in Chinese mythology who oversees the realm of the dead, and -neta (-νήτης), an element in several spider names conventionally taken to mean ‘spinner’ (
Distinguished from other mysmenid genera except Maymena by the presence of a modified spatulate seta on the PLS (
Relatively large mysmenids (>2 mm). Femoral spots on legs I and II in female, leg I only in male. Legs with macrosetae on the femora, tibiae, and metatarsi, especially in the anterior legs. Male clasping spurs arise from distal part of tibia I and basal third of metatarsus I. Leg formula IV-I-II-III. Carapace subovate, ocular area slightly raised. Eight eyes in two rows. AME black and with dark base, others reflective. ALE and PLE contiguous. ARE procurved, PRE straight (Fig.
Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov., Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov.
Gaoligong Mountains, Yunnan, China.
Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, “a nameless cave”, male A, B, E, F Left palp C cymbium D palpal bulb G partial leg I A, E, G prolateral B, F retrolateral C prolateral D retrolateral. Abbreviations: BC base of cymbium; BH basal haematodocha; CA cymbial apophysis; CS clasping spine on leg I; Cy cymbium; CyC cymbial conductor; CyFs setae on cymbial fold; E embolus; PC paracymbium; SD spermatic duct; T tegulum; Ti tibia; TS tibial spine on leg I; TTr trichobothrium on tibia; TiS setae on palpal tibia. Scale bars: 0.50 mm.
Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, “a nameless cave”, female genitalia A, B Epigyne C–D vulva (lactic acid treated) A, C ventral B lateral D dorsal. Unlabeled arrow in B indicates curved profile of dorsal surface of scape, in D indicates notched lateral margin of scape. Abbreviations: CD copulatory ducts; FD fertilization ducts; S spermathecae; Sp scape. Scale bars: 0.10 mm.
Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], male A, B, E, F Left palp C cymbium D palpal bulb G partial leg I A, E, G prolateral; B, F retrolateral; C prolateral; D retrolateral. Abbreviations: BC base of cymbium; BH basal haematodocha; CA cymbial apophysis; CS clasping spine on leh I; Cy cymbium; CyC cymbial conductor; CyFs setae on cymbial fold; E embolus; PC paracymbium; SD spermatic duct; T tegulum; Ti tibia; TS tibial spine on leg I; TTr trichobothria on tibia; TiS seta on palpal tibia. Scale bars: 0.50 mm.
CHINA • 2♂♂, 25♀♀ multiple juveniles; Yunnan Province, Nujiang Lisu Autonomous Prefecture, Fugong County, Shiyueliang Town, Lishadi Village, 3.9 km E of Yamu River Fork, “a nameless cave”; 27.12818N, 98.86014E; 1500 m a.s.l.; 18 Aug. 2018; Y.C. Li, Y. Li, Y.F. Shu & Y.C. Lin leg.; NHMSU • 1♂; same data as for preceding; GenBank: MK908789, MK908805, MK908797, MK895530, MK895538; GlgMY14 male • 1♀; same data as for preceding; GenBank: MK908790, MK908806, MK908798, MK895531, MK895539; GlgMY14 female • 1 juvenile; same data as for preceding; GenBank: MK908791, MK908807, MK908799, MK895532, MK895540; GlgMY14 juv. • 1♂; same data as for preceding; GenBank: MK908792, MK908808, MK908800, MK895533, MK895541; GlgMY15 male • 1♀; same data as for preceding; GenBank: MK908793, MK908809, MK908801, MK895534, MK895542; GlgMY15 female.
Yamaneta kehen can be distinguished from its congener Y. paquini by having only a single proximal-dorsal trichobothrium (TTr) and a single long distal-ventral setae (TiS) on the male palpal tibia, but 2 of each in Y. paquini (Fig.
Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], female genitalia A, B Epigyne C–D vulva (lactic acid treated) A, C ventral B lateral D dorsal. Unlabeled arrow in B indicates curved profile of dorsal surface of scape, in D indicates notched lateral margin of scape. Abbreviations: CD copulatory ducts; FD fertilization ducts; S spermathecae; Sp scape. Scale bars: 0.10 mm.
Webs of Yamaneta spiders in the Gaoligong Mountains A Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, “a nameless cave”, female B Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], female. Red arrows indicate location of spider. Scale bars: 20.0 mm.
Male. Somatic coloration and characters see Fig.
Measurements: Total length 2.19. Carapace 1.13 long, 1.12 wide. Clypeus 0.26 high. Sternum 0.57 long, 0.58 wide. Abdomen 1.09 long, 1.10 wide. Length of legs: I 6.98 (2.13, 0.66, 1.77, 1.27, 1.15); II 5.92 (1.83, 0.57, 1.46, 1.12, 0.94); III 3.93 (1.28, 0.39, 0.86, 0.74, 0.66); IV 4.25 (1.42, 0.40, 0.97, 0.83, 0.63).
Male palp (Fig.
See Fig.
Measurements: Total length 2.48. Carapace 1.12 long, 1.10 wide. Clypeus 0.25 high. Sternum 0.64 long, 0.63 wide. Abdomen 1.43 long, 1.30 wide. Length of legs: I 6.46 (1.95, 0.63, 1.65, 1.21, 1.02); II 5.55 (1.66, 0.61, 1.38, 1.05, 0.85); III 3.82 (1.22, 0.42, 0.84, 0.73, 0.61); IV 4.09 (1.44, 0.40, 0.93, 0.75, 0.57).
Vulva (Fig.
Known from a single cave in Yunnan, China.
This species lives in the dark zone of the cave. They build a web typical of Maymena (e.g.,
CHINA • 2♂♂ 3♀♀ 2 juveniles; Yunnan Province, Nujiang Lisu Autonomous Prefecture, Lushui County, Daxingdi Town, Walayaku [cave]; 26.13198N, 98.86149E; 940 m a.s.l.; 24 June 2016; Y.C. Li leg.; NHMSU • 2♂♂ 20♀♀ multiple juveniles; same data as for preceding; 18 Aug. 2018; Y.C. Li, Y. Li, Y.F. Shu & Y.C. Lin leg.; NHMSU • 1♂; same data as for preceding; GenBank: MK908794, MK908810, MK908802, MK895535, MK895543; GlgMY16 male • 1♀; same data as for preceding; GenBank: MK908795, MK908811, MK908803, MK895536, MK895544; GlgMY16 female • 1 juvenile; same data as for preceding; GenBank: MK908796, MK908812, MK908804, MK895537, MK895545; GlgMY16 juv.
See Y. kehen.
Male. Somatic characters see Fig.
Measurements: Total length 2.22. Carapace 1.10 long, 1.00 wide. Clypeus 0.25 high. Sternum 0.58 long, 0.60 wide. Abdomen 1.13 long, 0.99 wide. Length of legs: I 6.95 (2.10, 0.66, 1.79, 1.25, 1.15); II 5.88 (1.82, 0.57, 1.45, 1.12, 0.92); III 3.96 (1.31, 0.39, 0.86, 0.74, 0.66); IV 4.24 (1.42, 0.40, 0.96, 0.83, 0.63).
Male palp (Fig.
Somatic characters see Fig.
Measurements: Total length 2.48. Carapace 1.16 long, 1.12 wide. Clypeus 0.25 high. Sternum 0.64 long, 0.63 wide. Abdomen 1.43 long, 1.30 wide. Length of legs: I 6.66 (1.96, 0.64, 1.64, 1.31, 1.11); II 5.81 (1.73, 0.62, 1.36, 1.13, 0.97); III 3.98 (1.27, 0.40, 0.85, 0.78, 0.68); IV 4.69 (1.50, 0.66, 1.03, 0.85, 0.65).
Vulva (Fig.
Known from a single cave in Yunnan, China.
This species lives in the dark zone of the cave. The web documented in Fig.
The manuscript benefitted greatly from comments by reviewers Lara Lopardo and Gustavo Hormiga, and subject editor Charles Haddad. We thank Dr Yunchun Li (China West Normal University, Nanchong, Sichuan) for helping collect specimens in the field for this study, and also thank Mr Yingchun Li (Biodiversity Institute of Gongshan Administration Bureau, Gaoligong Mountain National Nature Reserve, Yunnan of China) for his support and help in our field works. This study was supported by the National Natural Science Foundation of China (NSFC-31772410, 31750002). Special thanks to Lara Lopardo, Gustavo Hormiga, and Gonzalo Giribet for supplying electronic versions of their DNA sequence alignments, and to F. Andrés Rivera-Quiroz for advice and support.
Alignment of DNA sequence data used in phylogenetic analyses
Data type: molecular data
Explanation note: Contains plain alignments in Fasta (FengetalAlignment.fas) and Nexus formats (FengetalAlignment.nex), plus the Nexus file used for data partition and tree search in MrBayes (FengetalAlignmentMrB.nex).
Uncorrected pairwise distances based on full alignment
Data type: molecular data
Explanation note: Contains uncorrected pairwise distances among all terminals as calculated using Mega X (