Research Article |
Corresponding author: Hung-Du Lin ( varicorhinus@hotmail.com ) Corresponding author: Wei-Kuang Wang ( wkwang@fcu.edu.tw ) Academic editor: Maria Elina Bichuette
© 2019 Xiao-Xia Huang, Kui-Ching Hsu, Bin Kang, Po-Hsun Kuo, Wan-Hsin Tsai, Chih-Ming Liang, Hung-Du Lin, Wei-Kuang Wang.
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:
Huang X-X, Hsu K-C, Kang B, Kuo P-H, Tsai W-H, Liang C-M, Lin H-D, Wang W-K (2019) Population structure of Aphyocypris normalis: phylogeography and systematics. ZooKeys 872: 77-90. https://doi.org/10.3897/zookeys.872.33105
|
Aphyocypris normalis (Teleostei: Cyprinidae) is an endemic species in South China, but little is known about its genetic structure. This study examined the population structure of A. normalis using sequences of the mitochondrial DNA control region and cytochrome b gene (2,086 bp). In total, 107 specimens were collected from nine populations. All 105 mtDNA haplotypes were identified as belonging to two allopatric phylogroups. The results of a statistical dispersal-vicariance analysis (S-DIVA) suggested that the ancestral populations of A. normalis were distributed widely on Hainan Island and east of the Leizhou Peninsula. A comparison of the fixation indices NST (0.532) and GST (0.004) revealed that the phylogeny and geography had a significant relationship. Our study found that (1) the Wuzhishan and Yinggeling Mountain Range was an important barrier limiting gene exchange between populations on both sides; (2) cyclic climate changes may have shaped migrations and population differentiations; and (3) different colonization times caused different population diversities between codistributed species. In addition, the inter- and intraspecific diversities of the genus Aphyocypris were estimated.
Dispersal, Hainan Peninsula, Vicariance, Wuzhishan and Yinggeling Mountains Range
Hainan Island is located in the transitional zone between tropical and temperate zones. The island is separated from mainland China to the north by the Qiongzhou Strait and from mainland Vietnam to the west by the Gulf of Tonkin. Hainan Island was first isolated from the mainland by the results of volcanism and rising sea levels approximately 2–2.5 million years ago (mya) (e.g.,
The Wuzhishan and Yinggeling Mountain Range (WY Range) rises steeply from the central and southern regions of Hainan Island and gives way to a broad plain in the north.
Aphyocypris normalis is a small cyprinid fish restricted to Hainan Island and its adjacent area. Thus, this species is an ideal freshwater fish species to study the biological consequences of the geological history of river systems in this area. Aphyocypris normalis was named Nicholsicypris normalis until 2011.
The major questions in our study are as follows: (1) What are the taxonomic boundaries within Aphyocypris and its close relatives? (2) How did A. normalis colonize the rivers on the island and mainland? (3) Is there a phylogeographic break in freshwater fish on Hainan Island? To address the aforementioned questions, the mitochondrial DNA cytochrome b gene and control region sequences (hereafter mtDNA) were used to evaluate the phylogenetic relationships and population genetic structure (e.g.,
A total of 107 specimens of A. normalis was collected from nine localities on Hainan Island and mainland China (Fig.
Sampling locations, abbreviation (Abbr.) and summary statistics of Aphyocypris normalis. Haplogroups correspond to the haplogroups recover in BEAST phylogeny (Fig.
River | Locations (Abbr.) | Latitude / Longitude | Sample size | Haplotype diversity (h) | Nucleotide diversity (%) | phylogroup | |
θπ | θω | ||||||
North of Yunkai Mountains | |||||||
Dongjiang | Heyuan (HY) | 23°44'N, 114°42'E | 14 | 0.99 | 0.23 | 0.32 | I |
South of Yunkai Mountains | |||||||
East of Leizhou Peninsular | |||||||
Moyangjiang | Yangchung (MY) | 22°26'N, 111°56'E | 11 | 1.00 | 0.61 | 0.71 | I |
Jianjiang | Hexi (HE) | 22°21'N, 110°56'E | 14 | 1.00 | 1.12 | 1.16 | I |
West of Leizhou Peninsular | |||||||
Beilun River | Dongxing (DX) | 21°32'N, 107°58'E | 7 | 1.00 | 1.08 | 1.26 | I |
Hainan Island | |||||||
Northern | |||||||
Nandu River | Haikou (HO) | 19°57'N, 110°19'E | 13 | 1.00 | 0.97 | 1.23 | I |
Wanquan River | Qionghai (QH) | 19°09'N, 110°18'E | 8 | 1.00 | 1.43 | 1.68 | I |
Zhubijang | Basha (BS) | 19°13'N, 109°26'E | 11 | 1.00 | 0.85 | 0.97 | I |
Southern | |||||||
Lingshui River | Baoting (BT) | 18°38'N, 109°42'E | 20 | 0.99 | 0.50 | 0.52 | II |
Changhua River | Thanhuna (TH) | 18°46'N, 109°30'E | 9 | 1.00 | 0.68 | 0.78 | II |
Total | 107 | 1.00 | 1.49 | 2.45 |
Nucleotide sequences were aligned in Clustal X 1.81 (
A phylogenetic tree was created by BEAST 1.8.0 (
In addition, to determine the possible diversification scenarios of A. normalis, a statistical dispersal-vicariance analysis (S-DIVA), a program that complements DIVA, was employed to determine statistical support for ancestral range reconstructions (
Although the genus Aphyocypris was included in Danioninae,
within | A2 | A3 | A4 | A5 | B | B2 | C | C2 | D | D2 | D3 | D4 | D5 | D6 | D7 | |
A. Aphyocypris | 3.15 | 15.31 | 16.02 | 18.22 | ||||||||||||
A1. A. normalis | 2.28 | 5.78 | 9.74 | 12.59 | 12.52 | |||||||||||
A2. A. moltrechti | 1.11 | 8.92 | 11.78 | 11.64 | ||||||||||||
A3. A. arcus | – | 11.67 | 11.58 | |||||||||||||
A4. A. kikuchii | – | 2.63 | ||||||||||||||
A5. A. chinensis | 2.33 | |||||||||||||||
B. Candidia | 8.77 | 12.39 | 16.91 | |||||||||||||
B1. C. barbatus | – | 8.77 | ||||||||||||||
B2. C. pingtungensis | – | |||||||||||||||
C. Nipponocypris | 11.40 | 16.17 | ||||||||||||||
C1. N. seiboldii | – | 11.4 | ||||||||||||||
C2. N. temminckii | – | |||||||||||||||
D. Opsariichthys | 10.69 | |||||||||||||||
D1. O. bidens | 6.58 | 12.81 | 13.25 | 14.21 | 12.54 | 12.46 | ||||||||||
D2. O. uncirostris | 13.42 | 13.33 | 13.95 | 13.42 | 12.63 | |||||||||||
D3. O. evolans | 9.21 | 9.47 | 9.74 | 9.12 | ||||||||||||
D4. O. hainanensis | 7.28 | 9.47 | 9.39 | |||||||||||||
D5. O. minutus | 8.60 | 9.39 | ||||||||||||||
D6. O. pachycephalus | 4.30 | |||||||||||||||
D7. O. kaopingensis |
The complete 1,141 base pairs (bp) of cyt b (MH909846-MH909955) and 945 bp of the control region (MH909956-MH910020) sequences were analyzed. A total of 105 haplotypes (2,086 bp, 270 variable sites and 170 phylogenetic informative sites) were obtained for 107 sequences from nine populations analyzed (Table
All mtDNA haplotypes were population-private haplotypes. Our study found that the sequences were unique, excluding two identical sequences within populations BT and HY. Geographical division assessed by DnaSP indicated significant differentiation among populations (FST = 0.530). The pairwise FST values ranged from 0.144 (between populations HO and QH) to 0.820 (between populations HY and BT) (Table
Matrix of pair-wise FST (below diagonal) and p values (above diagonal) based on mtDNA in N. normalis. Refer to Table
MY | HE | DX | HO | QH | BS | BT | TH | |
HY | 0.67 | 0.57 | 0.62 | 0.56 | 0.49 | 0.72 | 0.82 | 0.79 |
MY | 0.00 | 0.38 | 0.45 | 0.37 | 0.29 | 0.59 | 0.71 | 0.67 |
HE | 0.00 | 0.00 | 0.27 | 0.26 | 0.18 | 0.46 | 0.61 | 0.57 |
DX | 0.00 | 0.00 | 0.00 | 0.29 | 0.18 | 0.52 | 0.64 | 0.57 |
HO | 0.00 | 0.00 | 0.00 | 0.00 | 0.14 | 0.51 | 0.61 | 0.58 |
QH | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.41 | 0.54 | 0.50 |
BS | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.73 | 0.69 |
BT | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.44 |
The Bayesian phylogenetic tree is shown in Figure
Scheme | Category description | % Var. | Statistic | P |
1. Two geological groups (HY+MY+HE +DX) (HO+QH+BS+TH+BT) | ||||
Among regions | 4.54 | F SC = 0.54 | <0.001 | |
Among populations in region | 51.64 | F ST = 0.56 | <0.001 | |
Within population | 43.82 | F CT = 0.05 | <0.001 | |
2. Three geological groups (HY) (MY+HE +DX) (HO+QH+BS+TH+BT) | ||||
Among regions | 4.65 | F SC = 0.54 | <0.001 | |
Among populations in region | 51.37 | F ST = 0.56 | <0.001 | |
Within population | 43.98 | F CT = 0.05 | <0.001 | |
3. Four geological groups (HY) (MY+HE) (DX) (HO+QH+BS+TH+BT) | ||||
Among regions | -0.16 | F SC = 0.55 | <0.001 | |
Among populations in region | 55.41 | F ST = 0.55 | <0.001 | |
Within population | 44.75 | F CT = -0.00 | <0.01 | |
4. Four geological groups (HY) (MY+HE +DX) (HO+QH+BS) (TH+BT) | ||||
Among regions | 18.82 | F SC = 0.39 | <0.001 | |
Among populations in region | 32.03 | F ST = 0.51 | <0.001 | |
Within population | 49.14 | F CT = 0.19 | <0.01 | |
5. Two phylogroups (HY+HE+MY+DX+QH+BS+HO) (TH+BT) | ||||
Among regions | 31.03 | F SC = 0.46 | <0.001 | |
Among populations in region | 31.94 | F ST = 0.63 | <0.001 | |
Within population | 37.03 | F CT = 0.31 | <0.01 | |
6. Five SAMOVA groups (HY) (HE+MY+DX+QH+HO) (BS) (TH) (BT) | ||||
Among regions | 34.53 | F SC = 0.37 | <0.001 | |
Among populations in region | 24.26 | F ST = 0.59 | <0.001 | |
Within population | 41.21 | F CT = 0.36 | <0.001 |
The coalescence time of A. normalis was estimated to be in the early Pleistocene (TMRCA= 2.33 mya, 1.92 – 2.74). The results of the S-DIVA analysis indicated that possible ancestral populations of A. normalis were distributed on Hainan Island and east of the Leizhou Peninsula. The rising of the WY Range on Hainan Island separated the populations into two groups, south and north of the WY Range. After a vicariance event, the populations in the north of the WY Range migrated to the west of the Leizhou Peninsula.
Today, the genera Pararasbora, Yaoshanicus, and Nicholsicypris are synonymous with the genus Aphyocypris. Our study considered that a genus should fulfill two criteria at least, monophyly and distinctness. In this study, the range of the p-distance among the genera Candidia, Nipponocypris and Opsariichthys was 12.39% to 16.17% (mean = 15.16%) (Table
The geological studies proposed that approximately 2–2.5 mya, Hainan was first isolated from the mainland by the results of volcanism and the ground fall in the current Qiongzhou Strait (e.g.,
Subsequently, our results found that the populations on southern Hainan Island (TH and BT) diverged by a vicariance event. At 0.458 mya, the WY Range arose on Hainan Island and isolated the population in the southern Hainan Island region as lineage II (Fig.
Based on previous studies (
Our study found that A. normalis (this study) and G. orientalis (
This work was supported by grants from the Ministry of Science and Technology, Taiwan (MOST107-2221-E-035-006-) and the National Science Foundation of China (No. 41476149 and No. 31560181).