An international team of scientists, including researchers from the Portuguese research institute CIIMAR, has developed a groundbreaking genomic tool that could help breed clams more resistant to disease and better adapted to climate change. The tool also supports the conservation of genetic diversity in these species. The study, published in the journal Aquaculture, marks a major advancement in sustainable aquaculture, particularly for two economically important clam species: the Japanese clam (Ruditapes philippinarum) and the common clam (Ruditapes decussatus). These clams are among the most widely farmed species globally, contributing significantly to the economies of many coastal communities. However, their production has been declining due to environmental factors such as habitat loss, climate change, and rising disease outbreaks. To tackle these challenges, the researchers created a new genomic tool that allows for the quick and affordable analysis of thousands of small genetic differences in clam DNA. These differences, known as genetic markers, can help identify clams with beneficial traits, such as stronger disease resistance, better climate adaptation, or faster growth. The technology used is called an SNP (Single Nucleotide Polymorphism) chip, which is the first high-density genotyping platform specifically developed for these two clam species. The tool includes approximately 63,000 genetic markers—more than 45,000 validated for the Japanese clam and 15,000 for the common clam. This technology supports breeding programs aimed at improving clam genetics, identifies family relationships among individuals, monitors genetic diversity, and tracks inbreeding within populations. These capabilities are essential for managing marine resources in a more sustainable way. A research group called Aquatic Animal Health (A2S) discovered over 13,000 genetic markers in the common clam that indicate resistance or susceptibility to Perkinsus olsenii, a parasite that causes major losses in clam farming. This research was published in the journal Evolutionary Applications. The new platform is now available to the scientific community, enabling faster selective breeding, studies linking genetic traits to economically important characteristics, and the monitoring of wild clam populations. This tool is expected to be vital for both aquaculture and the conservation of these species. Beyond aquaculture, the platform also offers new opportunities for studying how these clams respond to environmental changes, helping to protect marine biodiversity and increase the resilience of aquaculture. The project involved collaboration between scientists from several countries, including Portugal, Italy, Spain, the United Kingdom, and France, as well as companies like Benchmark Genetics and Thermo Fisher Scientific. This partnership highlights how combining research and industry efforts can turn scientific discoveries into practical solutions for sustainable aquaculture and marine resource management.