International Journal of Marine Science, 2025, Vol.15, No.4, 179-185 http://www.aquapublisher.com/index.php/ijms 179 Feature Review Open Access Comparative Genomics of Oysters and Evolutionary Adaptation to Marine Environments Liting Wang, Manman Li Hainan Institute of Biotechnology, Haikou, 570206, Hainan, China Corresponding author: manman.li@hitar.org International Journal of Marine Science, 2025, Vol.15, No.4, doi: 10.5376/ijms.2025.15.0016 Received: 05 Jun., 2025 Accepted: 10 Jul., 2025 Published: 20 Jul., 2025 Copyright © 2025 Wang and Li, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Wang L.T., and Li M.M., 2025, Comparative genomics of oysters and evolutionary adaptation to marine environments, International Journal of Marine Science, 15(4): 179-185 (doi: 10.5376/ijms.2025.15.0016) Abstract Oysters are important for both marine ecosystems and aquaculture, but they are under threat from climate change, pollution, and disease.Recent studies of oyster genomes-such as the Pacific oyster (Crassostrea gigas) and the Hong Kong oyster (Magallana hongkongensis)-have uncovered key differences in their genetic structure, gene activity, and stress responses. These discoveries help explain how oysters manage to survive in environments with different salinity, temperature, and pathogens. The comparison between C. gigas and M. hongkongensis shows clear genetic divergence related to their habitats. By identifying genes linked to stress tolerance, researchers can support future breeding and conservation efforts-especially as climate conditions continue to change. Keywords Oyster genomics; Environmental adaptation; Stress response; Salinity tolerance; Conservation genetics 1 Introduction Oysters are not only delicious food on people's tables, they also have other important functions. They can purify seawater, provide habitats for small marine organisms, and help maintain the nutrient balance in coastal environments (Parker et al., 2023; Zapata-Restrepio et al., 2023). In many coastal areas, oyster farming has become part of the local economy, providing many jobs and food sources. However, oysters are under growing pressure. Warmer oceans, heavier pollution, and the emergence of new diseases are making it harder for oysters to survive and reproduce (Xu et al., 2017; Brew et al., 2020). Different oyster species react in different ways-some can handle stress better than others. To understand why some oysters can withstand these challenges, scientists began to study their genes. By comparing the genetic differences between different species and populations, researchers have found genetic characteristics related to disease resistance and environmental adaptation (Eierman and Hare, 2016; Farias et al., 2017; Sullivan and Proestou, 2021; Dupoué et al., 2023). These research results also provide a reference for future oyster breeding and resource protection. 2 Progress in Oyster Genome Sequencing 2.1 Sequencing of Crassostrea and other related oysters In recent years, oyster genome sequencing technology has been greatly improved. Several important oysters, including the Pacific oyster (Crassostrea gigas), the Yangtze River oyster (Crassostrea ariakensis), the European oyster (Ostrea edulis), and the Hong Kong oyster (Magallana hongkongensis), have completed chromosome-level genome assemblies (Li et al., 2020; Qi et al., 2021; Gundappa et al., 2022). For example, the genome of C. gigas is divided into 10 pseudochromosomes, showing complex structure and genetic diversity (Qi et al., 2021; Mrowicki and Uhl, 2024). Different sequencing projects have different focuses. Some are used to study the evolution of oysters, while others directly provide data for breeding. For example, the genome of C. ariakensis can be used for conservation research and is also suitable for reference in aquaculture breeding (Li et al., 2024a). The genome of the European
RkJQdWJsaXNoZXIy MjQ4ODYzNA==