Corresponding author: Chih-Wei Huang (
Academic editor: M. Schilthuizen
Huang C-W, Lee Y-C, Lin S-M, Wu W-L (2014) Taxonomic revision of
Traditional morphology-based taxonomy provides a window to explore biodiversity and evolutionary history. The application of molecular genetic markers opens new avenues to discover biodiversity. In recent years, it was found that the species richness of land snails bearing comparably few morphological characteristics and exhibiting limited abilities of dispersal had been underestimated once molecular tools were applied (
Taiwan is a continental island that was formed through the collision of the Philippine Sea fig and the Eurasian fig. This collision uplifted the Central Mountain Range (CMR), forming a major physical barrier for animals inhabit lowland areas. The CMR has contributed to evolutionary divergences between organisms on either side of the CMR both on interspecific and intraspecific levels (
Live snails identified as
Sampling information and GenBank accession number of DNA sequences
GPS coordinates | Sample size | GenBank accession number | ||||||
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Sampling locality | Latitude | Longitude | Altitude | NG | NM | COI | 16S | ITS2 |
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# Wulai, Taipei | NA. | NA. | NA. | 1 | 0 |
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NA. |
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1. Linmei Shipan Trail, Jiaoxi Twp., I-Lan Co., Taiwan |
|
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286 | 2 | 2 |
|
||
2. Houtong, Ruifang District, New Taipei City, Taiwan |
|
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105 | 0 | 3 | NA. | NA. | NA. |
3. Zhishanyan, Taipei City, Taiwan |
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53 | 3 | 5 | |||
4. Datieliao Trail, Daxi Twp., Taoyuan City, Taiwan |
|
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433 | 0 | 1 | NA. | NA. | NA. |
5. Shimen Reservoir 1, Daxi Twp., Taoyuan City, Taiwan |
|
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323 | 0 | 5 | NA. | NA. | NA. |
6. Shimen Reservoir 2, Daxi Twp., Taoyuan City, Taiwan |
|
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198 | 0 | 1 | NA. | NA. | NA. |
7. Frog Rock, Jianshi Twp., Hsinchu Co., Taiwan |
|
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468 | 0 | 5 | NA. | NA. | NA. |
8. Fuxing Coal Mine, Jianshi Twp., Hsinchu Co., Taiwan |
|
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512 | 0 | 1 | NA. | NA. | NA. |
9. Jinping, Jianshi Twp., Hsinchu Co., Taiwan |
|
|
638 | 0 | 1 | NA. | NA. | NA. |
10. Shishan Trail, Nanzhuang Twp., Miaoli Co., Taiwan |
|
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344 | 0 | 5 | NA. | NA. | NA. |
11. Fengmei, Nanzhuang Twp., Miaoli Co., Taiwan |
|
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695 | 0 | 2 | NA. | NA. | NA. |
12. Dacaopai, Sanyi Twp., Miaoli Co., Taiwan |
|
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523 | 0 | 3 | NA. | NA. | NA. |
13. Wu Shi Branch School, Heping District, Taichung City, Taiwan |
|
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650 | 0 | 1 | NA. | NA. | NA. |
14. Wushikeng, Heping District, Taichung City, Taiwan |
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894 | 2 | 0 | NA. | NA. | |
15. Huanshan, Heping District, Taichung City, Taiwan |
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1560 | 2 | 1 |
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|
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16. Anpingkeng, Dongshan Twp., I-Lan Co., Taiwan |
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70 | 4 | 5 |
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17. Wushibi, Su'ao Twp., I-Lan Co., Taiwan |
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382 | 1 | 0 |
|
|
|
18. Chaoyang Trail, Nan'ao Twp., I-Lan Co., Taiwan |
|
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42 | 0 | 2 | NA. | NA. | NA. |
19. Heren 1, Xiulin Twp., Hualien Co., Taiwan |
|
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36 | 0 | 1 | NA. | NA. | NA. |
20. Heren 2, Xiulin Twp., Hualien Co., Taiwan |
|
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55 | 0 | 7 | NA. | NA. | NA. |
21. Heren Trail, Xiulin Twp., Hualien Co., Taiwan |
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50 | 5 | 1 | |||
22. Jinwen Tunnel, Xiulin Twp., Hualien Co., Taiwan |
|
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128 | 0 | 8 | NA. | NA. | NA. |
23. Northern Chongde Tunnel, Xiulin Twp., Hualien Co., Taiwan |
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62 | 2 | 2 | NA. | ||
24. Southern Chongde Tunnel, Xiulin Twp., Hualien Co., Taiwan |
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56 | 3 | 5 | |||
25. Sanjianwu, Xiulin Twp., Hualien Co., Taiwan |
|
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165 | 0 | 6 | NA. | NA. | NA. |
26. Taroko Service Center, Xiulin Twp., Hualien Co., Taiwan |
|
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100 | 0 | 6 | NA. | NA. | NA. |
27. Badagang, Xiulin Twp., Hualien Co., Taiwan |
|
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421 | 5 | 0 | |||
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# Miyako Island, Japan | NA. | NA. | NA. | 1 | 0 |
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NA. |
|
28. Shimozaki, Miyako Island, Japan |
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32 | 3 | 0 |
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|
|
29. Hirara 1, Miyako Island, Japan |
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42 | 1 | 0 | NA. |
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30. Hirara 2, Miyako Island, Japan |
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44 | 3 | 0 |
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31. Shimozato, Miyako Island, Japan |
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44 | 6 | 0 | |||
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# IriomoteIsland, Japan | NA. | NA. | NA. | 1 | 0 |
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NA. |
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32. Tozato, Ishigaki Island, Japan |
|
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94 | 1 | 0 | NA. |
|
|
33. Fukai, Ishigaki Island, Japan |
|
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62 | 6 | 0 | |||
|
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# Ishigaki Island, Japan | NA. | NA. | NA. | 1 | 0 |
|
NA. |
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34. Fuyang Park, Taipei City, Taiwan |
|
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32 | 1 | 0 |
|
|
|
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35. Neiwan, Hengshan Twp., Hsinchu Co., Taiwan |
|
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268 | 1 | 0 |
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|
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||||||||
36. Lanren Rd., Manzhou Twp., Pingtung Co., Taiwan |
|
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48 | 1 | 0 |
|
|
|
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||||||||
37. Gueishan Island, Taiwan |
|
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157 | 1 | 0 |
|
|
|
NG: Number of specimen for Genetic analyses; NM: Number of specimen for Morphological analyses; #: sequence obtained from
Sequences were visually checked using Bioedit version 7.2.5 (
For genital morphological comparison, we dissected two samples of one adult snail each from the western (Zhishanyan, Taipei City) and the eastern (Heren 1, Xiulin Township, Hualien County) population, respectively (Table
Shell morphological comparisons were based on examination of 36 specimens of
Morphometric measurement of shell size variation of
A total of 50 individuals were sequenced from the
Maximum likelihood phylogeny and sampling sites of
No haplotypes were shared among species for COI, 16S or ITS2 genes (Figure
Haplotype networks of mitochondrial COI, 16S and nuclear ITS2 genes. Species are presented by colors. Haplotype frequency is shown by the size of the circular. Name of haplotype is numbered and presented inside the circle. Haplotypes are connected by simple line represent one mutation between haplotypes. Number of mutations between haplotypes are shown in square. Red dots are missing or hypothetical haplotypes.
Gene trees and haplotype networks suggested the western and the eastern
The mean genetic distance between the western and the eastern
Interspecific divergence and intraspecific polymorphism of
|
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0.007/0.005/0.002 | |||
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0.075/0.036/0.015 | 0.002/0.008/0.004 | ||
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0.067/0.051/0.014 | 0.064/0.034/0.007 | 0.023/0.014/0.004 | |
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0.085/0.037/0.016 | 0.065/0.038/0.009 | 0.059/0.042/0.008 | 0.024/0.012/0.004 |
The major differences of genital morphology of the western and the eastern
Genital morphology of
Measurements for genital morphology of
Measurement | HD | AG | SOD | FO | V | DS | P | E | EF |
---|---|---|---|---|---|---|---|---|---|
|
0.77 | 0.24 | 1.05 | 0.20 | 0.20 | 0.23 | 0.34 | 0.32 | 0.29 |
|
0.73 | 0.88 | 1.38 | 0.22 | 0.33 | 0.45 | 0.33 | 0.45 | 0.57 |
|
HD/AG | AG/SOD | HD/SOD | FO/V | EF/E | E/P | P/V | ||
|
3.19 | 0.23 | 0.73 | 1.00 | 0.89 | 0.94 | 1.75 | ||
|
0.84 | 0.63 | 0.53 | 0.66 | 1.25 | 1.37 | 1.01 |
AG: albumen gland; DS: dart-sac of auxiliary copulatory organ; E: epiphallus; EF: epiphallial flagellum; FO: free oviduct; HD: hermaphroditic duct; P: penis; SOD: spermoviduct; V: vagina.
The eastern and western populations of
Principle component analysis (PCA) of
Mean shell shape of
Measurements (in cm) of
|
|
|
|
whorls | 7.21±0.04 | 7.23±0.05 | M |
shell width (SW) | 1.97±0.02 | 2.46±0.04 | W, |
shell height (SH) | 1.04±0.01 | 1.21±0.02 | M, |
aperture width (AW) | 0.75±0.01 | 0.97±0.02 | W, |
aperture height (AH) | 0.53±0.01 | 0.74±0.02 | W, |
umbilicus width (UW) | 0.72±0.01 | 0.95±0.02 | M, |
body whorl height (BH) | 0.57±0.01 | 0.68±0.01 | W, |
secondary body whorl height (SBH) | 0.10±0.00 | 0.10±0.00 | M |
Angle of apex (AA) | 150.8±0.65 | 154.7±0.67 | M, |
First whorl width (FW) | 0.14±0.00 | 0.16±0.00 | M, |
2nd whorl width (2W) | 0.06±0.00 | 0.07±0.00 | M, |
3rd whorl width (3W) | 0.08±0.00 | 0.10±0.00 | M, |
4th whorl width (4W) | 0.12±0.00 | 0.14±0.00 | M, |
5th whorl width (5W) | 0.16±0.00 | 0.19±0.00 | M, |
6th whorl width (6W) | 0.20±0.00 | 0.25±0.00 | M, |
SH/SW | 0.53±0.01 | 0.49±0.00 | W, |
AW/SW | 0.38±0.00 | 0.39±0.00 | M, |
UW/SW | 0.37±0.00 | 0.39±0.01 | M |
AH/SH | 0.51±0.01 | 0.62±0.01 | W, |
AH/AW | 0.70±0.01 | 0.76±0.01 | W, |
SH/UW | 1.45±0.02 | 1.28±0.03 | M, |
AW/UW | 1.05±0.01 | 1.03±0.02 | M |
AH/UW | 0.73±0.01 | 0.79±0.02 | M, |
BH/SW | 0.29±0.00 | 0.28±0.00 | M, |
BH/SH | 0.55±0.00 | 0.57±0.01 | W, |
BH/UW | 0.79±0.01 | 0.73±0.02 | M, |
SBH/BH | 0.68±0.01 | 0.78±0.01 | W, |
SBH/SW | 0.05±0.00 | 0.04±0.00 | W, |
SBH/SH | 0.10±0.00 | 0.08±0.00 | W, |
SBH/UW | 0.15±0.01 | 0.11±0.00 | W, |
FW/SW | 0.07±0.00 | 0.06±0.00 | M, |
2W/3W | 0.75±0.03 | 0.68±0.01 | M |
3W/4W | 0.68±0.02 | 0.72±0.01 | M |
4W/5W | 0.76±0.01 | 0.70±0.01 | M, |
5W/6W | 0.79±0.01 | 0.77±0.01 | W |
M: Mann-Whitney
Based on the observed amounts of morphological and genetic differentiation, we conclude that the eastern and western populations assigned to
Shell images of
Taiwan, Hualian County, Xiulin Township, Forest around the Chongde Tunnel,
Anpingkeng, Dongshan Township, I-Lan County,
Named after the recent efforts supporting equal marriage rights in Taiwan and around the world. Derived from “diversus” (Latin for different) and “familia” (Latin for family), adjective of feminine gender.
Endemic to Taiwan and is currently known from I-Lan and Hualian Counties.
Live snails are generally found on the ground or under leaf litter in shady, moist environments in lowland hardwood forests (Figure
Living snail
The morphological divergence between the eastern and the western
The authors would like to thank Enago (
Gene trees of maximum likelihood and Bayesian inference and the morphological measurements of
phylogenetic tree/measurement
Figure S1. Maximum likelihood phylogeny of mitochondrial COI gene. Branch support confidences are shown in bootstrap and approximate likelihood-ratio test. Figure S2. Maximum likelihood phylogeny of mitochondrial 16S gene. Branch support confidences are shown in bootstrap and approximate likelihood-ratio test. Figure S3. Maximum likelihood phylogeny of nuclear ITS2 gene. Branch support confidences are shown in bootstrap and approximate likelihood-ratio test. Figure S4. Bayesian phylogeny of mitochondrial COI gene. Figure S5. Bayesian phylogeny of mitochondrial 16S gene. Figure S6. Bayesian phylogeny of nuclear ITS2 gene. Table S1. Morphological measurements of