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Article

Population Structure and Genetic Diversity of Oysters from a Natural Reef on Magu Island, Shandong, China

by
Yumeng Liu
1,
Sichao Pu
1,
Liang Zhang
1,
Yinglu Ji
1,
Jie Feng
1,
Peizhen Ma
2,3,* and
Lan Wang
1,*
1
North China Sea Marine Forecasting Center of State Oceanic Administration, Qingdao 266000, China
2
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Sciences, Qingdao 266071, China
3
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Marine Science and Technology Center, Qingdao 266237, China
*
Authors to whom correspondence should be addressed.
Diversity 2025, 17(10), 693; https://doi.org/10.3390/d17100693
Submission received: 4 September 2025 / Revised: 1 October 2025 / Accepted: 1 October 2025 / Published: 3 October 2025
(This article belongs to the Section Biodiversity Conservation)
Browse Figures
Versions Notes

Abstract

Oyster reefs are receiving increasing attention due to severe survival challenges and their significant ecological service functions. Despite increased restorations worldwide, both natural and restored reefs have often not been monitored to an extent. Reef-building oyster populations are the foundation for the development of oyster reefs. In order to provide basic data for further protection and potential restoration of the oyster reef in the muddy tidal flats of Magu Island, in the middle of Dingzi Bay, the population structure and genetic diversity of the reef-building oysters were assessed through field investigation and molecular experiments. Results showed that the area of the oyster reef was 20,689 square meters and the oysters were Magallana gigas. The distribution of oyster patches revealed a reef building-up stage. The mean densities of the oysters were 3260.80 ind·m−2 and 3097.60 ind·m−2 in spring and autumn, respectively, and the biomasses were 25,209.38 g·m−2 and 30,137.44 g·m−2. The frequent distribution of shell height indicated two primary sizes divided by ages. Population genetic analyses based on partial mitochondrial cox1, cox3, and nad2 showed low nucleotide diversity and moderate haplotype diversity, proposing the population growth stage. Both the results of the population structure and genetic diversity suggested a developing status of the oyster reef on Magu Island.

1. Introduction

Oyster reefs are among the most severely damaged coastal ecosystems [1,2]. Over the past century, overfishing, habitat degradation, environmental pollution, and coastal development have led to the degradation or disappearance of 85% of the world’s natural oyster reefs [3]. With global warming and ocean acidification in the background, the survival situation of oyster reefs is particularly precarious [4]. Oyster-reef restorations have been conducted worldwide, led mainly by the USA, Europe, and Australia, with standardized restoration metrics established [5]. Brood stock and oyster population enhancement are the primary goals for oyster reef restoration, and the metrics include oyster density, size-frequency distributions, and oyster abundance. The oyster reefs in some areas are gradually recovering, benefiting from increasing restoration efforts [6,7]. However, the conditions of oyster reefs could not be accurately assessed because of a lack of data [3]. Large-scale surveys on the distribution and ecological status of oyster reefs, as well as the reef-building oyster populations, are desperately needed [8]. At present, there are relatively few investigations and studies on the oyster reef habitats in China. This poses a significant challenge to understanding, protecting, and managing this habitat [9]. Therefore, understanding the status and dynamics of reef-building oyster populations is of great significance for targeted and effective conservation and restoration of oyster reefs.
Reef-building oysters are the keystone species in an oyster reef ecosystem. The common oysters in well-known reefs in the world include Crassostrea virginica (Gmelin, 1791) in the Chesapeake Bay [10], Ostrea lurida (P. P. Carpenter, 1864) in Puget Sound [11], Saccostrea glomerata (A. Gould, 1850) and O. angasi (G. B. Sowerby II, 1871) in Southern and Eastern Australia [12], O. edulis (Linnaeus, 1758) in Europe [13], as well as Magallana species in China, e.g., M. gigas (Thunberg, 1793), M. ariakensis (Fujita, 1929), M. sikamea (Amemiya, 1928), and M. hongkongensis (Lam & B. Morton, 2003) [9,14]. These oysters have long been treated as a source of marine animal protein and many oyster populations have been seriously damaged [2,15]. Due to morphological plasticity, molecular evidence have been employed to identify reef-building oyster species accurately and assess the population genetic diversity [16,17,18]. Furthermore, in oyster reef restoration projects, population genetic analyses can not only delineate the geographic distribution of germplasm diversity but also evaluate genetic dynamics, e.g., gene flow and genetic differentiation and restoration effects, e.g., transplant enhancement and recruitment contributions [19,20,21,22,23], using gene markers such as mitochondrial genes and microsatellite loci [20,21,23]. Hornick & Plough conducted a genome-wide analysis on both natural and restored oyster populations using 4641 SNPs and evaluated the fine-scale genetic structure and local adaptations of restored oysters [24]. However, considering the cost factor, the segmental fragments are still the main tool for studying the population genetics of reef-building oysters.
The oyster reef in the south of Magu Island, in the middle of Dingzi Bay in Shandong, China, has been treated as a source of edible oysters for a long time according to local residents. This area has been invaded by the spreading Spartina alterniflora Loisel. in 2009 [25], which was eradicated in 2021. The tidal flat was recovered, and it is a developing opportunity for the oyster reef on Magu Island now. However, the reef-building oyster population has never been reported. The aims of this study were to characterize the conditions and provide basic data for the protection and potential restoration of the natural oyster reef on Magu Island.

2. Materials and Methods

2.1. Investigation on the Population Structure of the Reef-Building Oysters on Magu Island

A multirotor unscrewed aerial vehicle (UAV, Phantom 4 RTK; Shenzhen Dajiang Innovation Technology Co., Ltd., Shenzhen, China) was used to conduct the aeromagnetic survey on the range of the oyster reef on 17 October 2023. The orthoimages were processed by the DJI Terra 3.0.0 software to generate the digital orthophoto map. The range of the oyster reef was then outlined and calculated. To study the population structure and the shell size distribution, five quadrats (25 cm × 25 cm, 25 cm deep, numbered one to five) in the oyster reef were randomly decided both in October 2023 (autumn) and April 2024 (spring), from which all the oysters were collected (Figure 1), washed out, and identified to be M. gigas by their morphological characteristics (small, intertidal, flat, and irregular in shape, distinct from M. ariakensis) [26]. Each sampling point was at least separated by ten meters. The oysters from each quadrat were counted and weighed to calculate the density and biomass. The shell height (the distance from the umbo to the distal margin of the shell) and shell length (the maximum distance perpendicular to the shell height from the shell surface) [5] of 200 random oysters were measured by a digital caliper. The parametric one-way ANOVA with Tukey multiple comparison tests by Microsoft Excel 2010 was used to compare differences between the survey results of October 2023 and April 2024, with the significance level set at 0.05.
To investigate the larval recruitment of the oyster reef on Magu Island, five granite boards (200 mm × 400 mm) were inserted in the reef area vertically. The spawning stage of oysters nearby begins in June and lasts till September [27]. Considering the planktonic larval stage, we arranged the boards on 6 June 2024 and recycled them on 21 October 2024. The attachment area of each board was measured, and the quantity of oysters was calculated. Again, the shell length and height of 200 random oysters were measured. The effective population size was estimated by calculating the harmonic mean of the population densities from the two generations [28].

2.2. Investigation on the Population Genetic Diversity of the Reef-Building Oysters on Magu Island

Because the reef-building oysters were identified as M. gigas, five mitochondrial genomes of M. gigas were downloaded from GenBank (accession nos. AF177226, EU672831, KJ855241, KJ855245, and MZ497416) to decide the proper molecular marker for population genetic analysis. The thirteen protein-coding gene sequences (cox 1–3, cytb, nad1–nad6, nad4l, atp6, and atp8) from all genomes were aligned by MAFFT v.7.526 software, with codon usage mode, following the invertebrate mitochondrial code table [29]. The codon-aware program MACSE v.2.03 was used to refine the alignments, preserve the reading frame, and allow incorporation of sequences or sequencing errors with frameshifts [30]. Gblocks was then employed to remove ambiguously aligned fragments in the 13 alignments [31]. The nonsynonymous substitution rate (Ka) and synonymous substitution rate (Ks) of each protein-coding gene was calculated by DnaSP v.6.12.03 software [32] to evaluate their selective pressure. Referring to the criterion (both Ka/Ks values and gene lengths considered) developed by Zhu et al. [33], nad2 was eventually chosen as a gene marker, as well as two widely used genes, i.e., cox1 and cox3.
The population genetic diversity of the reef-building oysters was estimated using 50 individuals, with 10 individuals from each quadrat selected randomly to make up the population in Apr. 2024. About 30 mg of adductor muscle from each sample was scissored for DNA extraction using a TIANamp marine animals DNA kit (DP324-03; Tiangen Biotech (Beijing), Beijing, China). The primers for amplification were COI-F (5′-CGATCTGTTGGGGGCCATTT-3′) and COI-R (5′-GGAGGCTAGACACAACAGCC-3′), COIII-F (5′-GGGTGCAAACTTATGGGGAG-3′) and COIII-R (5′-AGTTACACCAGCTCAGACAAC-3′), and NAD2-F (5′-GGCACATTAGTGTCGAGAGG-3′) and NAD2-R (5′-AGTTACACCAGCTCAGACAAC-3′) for cox1, cox3, and nad2, respectively. The 25 μL polymerase chain reaction (PCR) amplification system included 12.5 μL 2 × PCR Master Mix, 0.5 μL of each primer, 1 μL of DNA template, and 10.5 μL of ddH2O. The PCR amplification procedure was initial denaturation at 95 °C for 5 min, followed by 34 cycles of denaturation at 95 °C for 30 secs, annealing at 57 °C (cox1 and nad2) or 56 °C (cox3) for 62 secs, extension at 72 °C for 62 secs, and final extension at 72 °C for 10 min. The PCR products were sequenced by an Applied Biosystems 3730xl Genetic Analyzer (Tsingke Biotechnology Co., Ltd., Beijing, China). The sequences obtained were analyzed in the National Center for Biotechnology Information database using the basic local alignment search tool (BLAST, https://blast.ncbi.nlm.nih.gov/Blast.cgi on 23 November).
Sequences of the same gene marker were aligned by ClustalW, and adapter sequences were deleted using molecular evolutionary genetic analysis (MEGA) 11 [34]. Then DnaSP6 software [32] was employed to generate the genetic distance within population (Dis), number of haplotypes (h), haplotype diversity (Hd), nucleotide diversity (Pi), and average number of nucleotide differences (k) of the three gene markers from the reef-building oyster population. Finally, PopART 1.7 [35] and Arlequin suite ver 3.5 [36] were used to construct the haplotype networks of the three markers, respectively.

3. Results

3.1. Population Structure of the Reef-Building Oysters on Magu Island

The oyster reefs in the south of Magu Island, in the middle of Dingzi Bay, were located in the muddy tidal flat about 550 to 900 m offshore, with tidal creeks distributed across patches. The reefs covered a total area of 20,689 square meters (Figure 2a). Both sporadic individuals and reefs were found. Most of the reef-building oysters, M. gigas, exhibited upright growth with their hinges on the bottom (Figure 2b). The living oysters covered the tidal flat like a bed and dead shells were buried below.
The density of reef-building oysters ranged from 2528.00 ind·m−2 to 3904.00 ind·m−2, with a mean density of 3097.60 ind·m−2 in October 2023 and 3260.80 ind·m−2 in April 2024, respectively (Table 1). However, the mean biomass in Oct. 2023 was higher than that in Apr. 2024. Interestingly, the shell in April 2024 was larger than that in October 2023. Although the mean shell height was comparable, the mean shell length was significantly larger in April 2024 than in October 2023. The largest shell height in 2023 was 97.90 mm, while that in 2024 was 116.30 mm. The frequent distribution of shell height presented two peaks divided by 40 mm in both surveys: 15–20 mm (26 individuals) and 60–70 mm (30 individuals) in October 2023; 20–25 mm (18 individuals) and 60–65 mm (22 individuals) in April 2024 (Figure 3). For shell length, the interval of 15–20 mm had the largest frequency of 42 in 2023 and the interval of 20–25 mm had the largest frequency of 42 in 2024. The top five intervals of shell length for both surveys were from 5–10 mm to 25–30 mm, accounting for 84.0% and 85.5% of individuals in 2023 and 2024, respectively. The largest shell length was 52.40 mm in 2023 and 52.50 mm in 2024. The smallest shell length of only 4.50 mm was found in 2024.
All the five granite boards were successfully collected (Figure 4). The effective areas for recruitment were 390 cm2 to 456 cm2. The quantity of oysters recruited ranged from 122 to 453 for each board. As a result, the densities of the recruited oysters were 3128.21 to 10,850.00 ind·m−2, with a mean value of 8494.76 ind·m−2. Calculated using the densities of both the recruited oysters and that in April 2024, the effective population size was 4712.61 ind·m−2. The shell height of newly recruited oysters ranged from 10.00 mm to 49.00 mm and shell length ranged from 7.00 mm to 27.00 mm, with mean values of 29.58 mm and 15.86 mm. The frequent distributions showed that the interval of 30–35 mm had the largest frequency of 51 for shell height and the interval of 15–20 mm had the largest frequency of 83 for shell length (Figure 5). No recruited oysters were found with a shell height or length of less than 5 mm.

3.2. Population Genetic Diversity of the Reef-Building Oysters on Magu Island

Among the 13 mitochondrial protein-coding genes, nad5 was the longest of 1668 bp and atp8 was the shortest. Six genes, i.e., cox1, cytb, nad1, nad4l, nad6, and atp8, had no nonsynonymous substitutions, while cox2 had no synonymous substitutions (Table 2). The selective pressure analysis showed that all the mitochondrial protein-coding genes exhibited a purifying selection, with Ka/Ks values less than 1. Although nad3 experienced the least selective pressure, it was too short to provide enough substitution sites for population genetic analysis. As a result, nad2 was used as a gene marker along with cox1 and cox3 for the reef-building oysters on Magu Island. The partial cox1, cox3, and nad2 sequences of all the 50 individuals were obtained. The percentage identified between any newly obtained sequence and those in GenBank was over 99%, indicating that the reef-building oysters in this study was M. gigas. The haplotypes were uploaded to the GenBank with accession nos. PV194962–PV194973 for cox1, PV204822–PV204836 for cox3, and PV210309–PV210318 for nad2. The conserved regions of partial cox1, cox3, and nad2 for genetic analysis were 724 bp, 814 bp, and 765 bp, respectively. The genetic distances within populations corresponded to nucleotide diversity, with a maximum value of 0.0083 based on cox1. Gene marker cox3 had the most haplotypes, as well as the highest haplotype diversity and average number of nucleotide differences (Table 3).
All the three haplotype networks showed a “star” distribution (Figure 6). Among the 50 individuals, 38, 35, and 36 individuals constructed the center haplotypes of cox1, cox3, and nad2, i.e., Hap_1, Hap_A, and Hap_a, respectively. They were also the only three haplotypes shared by all five quadrats. Quadrat five had the most unique cox1 haplotypes of four, i.e., Hap_9 to Hap_12, while both quadrats three and four had the most unique cox3 haplotypes, i.e., Hap_E to Hap_H, and Hap_I to Hap_L, respectively. In all three haplotype networks, the differences between haplotypes were no more than three bases, which happened between Hap_1 and Hap_3 in cox1.

4. Discussion

The oyster reef in the south of Magu Island presented as an intertidal patch reef with oyster clusters on a muddy substrate. Sporadic individuals were considered as a sign of the initial stages of oyster reef development [37], especially soon after the eradication of invasive Spartina alterniflora [25]. This type of oyster reef on intertidal substrate was quite common in the estuary area. Take the oyster reefs developed in Holocene for example, when large-scale oyster reefs were found in estuary areas in East Asia [38,39,40,41]. The oyster reef in this study was in the stage of reef building-up, characterized by oysters attached to each other, clustered together, and growing upward [42,43]. However, the height of the reef made up of living oysters was limited and dead shells were buried below the surface of the tidal flats. On the one hand, the upright growth of oysters could possibly be a way of resisting the sediment deposition in this estuary [44]. On the other hand, there were no suitable substrates for the settlement of oyster larvae except existing oyster shells in the muddy flat of natural estuary regions. Consequently, the oysters could not develop into a high reef above the flat but formed a likely balance of “grow–sink–deposit”, which meant that the thickness of the newly formed reef and the growth rate of oyster individuals showed a linear relationship [37].
The mean density of live oysters in this study was over 3000 ind·m−2, comparable to that in the Caofeidian-Leting oyster reef [45], with M. gigas being reef-building oysters in both reefs. It seemed that M. gigas was capable of building more compact reefs than other oysters, compared with M. sikamea in the Liyashan oyster reef in Jiangsu [46], C. virginica in the restored oyster reef in the Indian River Lagoon, Florida [47], O. angasi in the flat oyster reef in Australia [48], as well as M. ariakensis in the estuary reefs of the Yellow River delta [49]. The size of the reef-building oysters in spring on Magu Island was larger than that in autumn, same as M. sikamea in the Liyashan oyster reef, indicating efficient juvenile recruitment through the breeding seasons in summer [46]. It was interesting to find the shell length in spring was significantly larger than that in autumn despite their shell heights being comparable. The form of oyster shells could be affected by living conditions [50,51]. For oysters, fast growth and nutrient accumulation happened in autumn to survive freeze shock during the winter season [52], which would change the form of the oyster shells. Although oysters would continue growing from April to October, it would be a challenge for adult oysters surviving the breeding summer seasons [27,53]. In addition, adult oysters have always been threatened by sediments in the runoff flowing from Wulong River [44]. These might be the main reasons oysters with shell heights over 100 mm could only be found in April. Oyster size-frequency distribution could provide information about oyster growth and population status [5]. The height-frequency distributions presented two size classes both in spring and autumn, divided by about 40 mm. Coincidentally, the largest shell height of newly recruited oysters in autumn was 49 mm, indicating that the size classes might have resulted from oysters of different ages: newly recruited oysters formed the small class and older oysters formed the large class [54]. Consequently, we can infer from Figure 3 that the first peak (15–20 mm) in the frequent distribution of shell height resulted from newly recruited oysters. In addition, density of recruited oysters was relatively high compared with other reefs [45,54]. The oyster recruitment would be affected by the substrate materials used for the settlement of oyster larvae [55,56]. The density of recruited oysters by granite boards was obviously higher than that by existed oyster shells in this study. This demonstrated that the oysters recruited were abundant and the substrates were limited for the oyster reef on Magu Island, reminding us that the way for reef restoration was to add substrates [5]. By using substrates with proper type and reef morphology, the oyster population would be establishing successfully and quickly [57].
Molecular tools are drawing increasing attention in oyster reef protection and restoration, not only in oyster species identification but also genetic analyses [18], with molecular markers such as mitochondrial DNA markers [19], microsatellite loci [19,58], and genomic SNPs [59,60]. Except for the commonly used mitochondrial cox1 and 16S, other highly variable genes were chosen for genetic studies based on selective pressure analysis [33,61]. The sequences of the three mitochondrial DNA markers in this study showed that all 50 individuals were M. gigas and the population had low nucleotide diversity (Pi < 0.005) and moderate haplotype diversity [62]. Based on cox1 and nad2, according to Grant & Bowen [62], the oyster population might have experienced bottleneck, possibly resulting from the invasion or eradication of S. alterniflora. But based on cox3, the population was suffering from a population bottleneck followed by rapid population growth and accumulation of mutations. The star-like haplotype network also indicated that the reef-building oyster had recently experienced population expansion [63]. In any case, the oyster population on Magu Island would grow rapidly and the oyster reef might develop. However, compared with other wild populations in China [64,65], the genetic diversity of the M. gigas population in this study was at a moderate level based on partial cox1 sequences. Our results also suggested that population genetic diversity would be misdirected using improper markers. Anyway, increased genetic diversity will also enhance the capacity of reef-building oysters to adapt to changing conditions [66]. But some measures, for example, importing oysters from other places, could also be counterproductive by potentially promoting the maladaptation of the introduced stocks. Continuous monitoring [5] was necessary to understand the population structure and genetics of developing oyster reefs, taking the reef on Magu Island as an example. And the baseline data obtained by this study are all the more important in the restoration context of such a reef.

5. Conclusions

Oyster reefs are typical coastal ecosystems in temperate estuaries and coastal zones. Due to their significant ecological functions, research on oyster reefs has gained momentum globally. Accurate baseline data form the foundation for rational conservation and restoration efforts. This study, through detailed surveys of the population structure and genetic diversity of oyster reefs on the muddy tidal flats to the south of Magu Island in Dingzi Bay, concludes that the reef-building oyster population is currently in a phase of rapid development. The abundant recruitment of oysters provides the necessary material basis for the development of oyster reefs. At present, molecular genetic studies on reef-building oysters are still relatively limited. As an important biological research tool, the application of molecular techniques to oyster reef research will yield more precise results and may represent a significant method for oyster reef research in the coming period.

Author Contributions

Conceptualization, Y.L. and P.M.; methodology, J.F. and P.M.; software, Y.L. and P.M.; validation, P.M. and L.W.; formal analysis, Y.L. and Y.J.; investigation, S.P. and L.Z.; resources, L.W.; data curation, Y.L. and P.M.; writing—original draft preparation, Y.L.; writing—review and editing, P.M. and L.W.; visualization, P.M.; supervision, L.W.; project administration, L.W.; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Natural Science Foundation of Shandong Province (No. ZR2024QD251), Marine Science & Technology Project of the North Sea Bureau, Ministry of Natural Resources of China (No. 202504), and Open Fund of Shandong Provincial Key Laboratory of Marine Ecology and Environment & Disaster Prevention and Mitigation (No. 202313).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data contained within the article.

Acknowledgments

We acknowledge Chenxia Zuo and Yi Zhu from the Institute of Oceanology, Chinese Academy of Sciences for support in molecular experiments.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Survey quadrats sized 25 cm × 25 cm before (a) and after (b) oyster collection in the oyster reefs on Magu Island.
Figure 1. Survey quadrats sized 25 cm × 25 cm before (a) and after (b) oyster collection in the oyster reefs on Magu Island.
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Figure 2. Oyster reefs on Magu Island. (a) Overall distribution (blue line) decided by UAV orthorection technology; (b) Reef-building oysters attached to each other and piled up.
Figure 2. Oyster reefs on Magu Island. (a) Overall distribution (blue line) decided by UAV orthorection technology; (b) Reef-building oysters attached to each other and piled up.
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Figure 3. Frequency distributions of shell height (a) and shell length (b) of the reef-building oysters on Magu Island.
Figure 3. Frequency distributions of shell height (a) and shell length (b) of the reef-building oysters on Magu Island.
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Figure 4. Granite boards sized 200 mm × 400 mm used for larval recruitment before (a) and after (b) picked up from muddy flat in the oyster reefs on Magu Island.
Figure 4. Granite boards sized 200 mm × 400 mm used for larval recruitment before (a) and after (b) picked up from muddy flat in the oyster reefs on Magu Island.
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Figure 5. Frequency distributions of shell height and shell length of the recruited oysters.
Figure 5. Frequency distributions of shell height and shell length of the recruited oysters.
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Figure 6. TCS networks for the reef-building oyster population on Magu Island based on (a) cox1, (b) cox3, and (c) nad2.
Figure 6. TCS networks for the reef-building oyster population on Magu Island based on (a) cox1, (b) cox3, and (c) nad2.
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Table 1. Survey results of the reef-building oysters on Magu Island. Values with different lowercase letters indicated significant difference.
Table 1. Survey results of the reef-building oysters on Magu Island. Values with different lowercase letters indicated significant difference.
Survey DateMean Density/ind·m−2Mean Biomass/g·m−2Mean Shell Length/mmMean Shell Height/mm
October 20233097.60 a30,137.44 a18.94 a43.54 a
April 20243260.80 a25,209.38 a21.48 b52.51 a
Table 2. The evolutionary constraint analyses of thirteen mitochondrial protein-coding genes. Ka, nonsynonymous substitution rate; Ks, synonymous substitution rate.
Table 2. The evolutionary constraint analyses of thirteen mitochondrial protein-coding genes. Ka, nonsynonymous substitution rate; Ks, synonymous substitution rate.
Protein-Coding GeneLengthKaKsKa/Ks
cox11614 bp0.000000.008220.00000
cox2699 bp0.000750.00000-
cox3873 bp0.000710.012050.05892
cytb1236 bp0.000000.008910.00000
nad1933 bp0.000000.001820.00000
nad2996 bp0.001050.005160.20349
nad3348 bp0.000150.004910.30550
nad41350 bp0.000390.006860.05685
nad4l282 bp0.000000.011540.00000
nad51668 bp0.001920.010070.19067
nad6474 bp0.000000.003510.00000
atp6681 bp0.000770.007310.10534
atp8117 bp0.000000.024390.00000
Table 3. Genetic diversity analysis based on cox1, cox3, and nad2. N, number of specimens; Dis, genetic distance within population; h, number of haplotypes; Hd, haplotype diversity; Pi, nucleotide diversity; k, average number of nucleotide differences.
Table 3. Genetic diversity analysis based on cox1, cox3, and nad2. N, number of specimens; Dis, genetic distance within population; h, number of haplotypes; Hd, haplotype diversity; Pi, nucleotide diversity; k, average number of nucleotide differences.
MarkerLengthNDishHdPik
cox1724 bp500.0083120.4250.000830.598
cox3826 bp500.0082150.5130.000820.677
nad2765 bp500.0077100.4810.000770.590
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Liu, Y.; Pu, S.; Zhang, L.; Ji, Y.; Feng, J.; Ma, P.; Wang, L. Population Structure and Genetic Diversity of Oysters from a Natural Reef on Magu Island, Shandong, China. Diversity 2025, 17, 693. https://doi.org/10.3390/d17100693

AMA Style

Liu Y, Pu S, Zhang L, Ji Y, Feng J, Ma P, Wang L. Population Structure and Genetic Diversity of Oysters from a Natural Reef on Magu Island, Shandong, China. Diversity. 2025; 17(10):693. https://doi.org/10.3390/d17100693

Chicago/Turabian Style

Liu, Yumeng, Sichao Pu, Liang Zhang, Yinglu Ji, Jie Feng, Peizhen Ma, and Lan Wang. 2025. "Population Structure and Genetic Diversity of Oysters from a Natural Reef on Magu Island, Shandong, China" Diversity 17, no. 10: 693. https://doi.org/10.3390/d17100693

APA Style

Liu, Y., Pu, S., Zhang, L., Ji, Y., Feng, J., Ma, P., & Wang, L. (2025). Population Structure and Genetic Diversity of Oysters from a Natural Reef on Magu Island, Shandong, China. Diversity, 17(10), 693. https://doi.org/10.3390/d17100693

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