Parasitic fauna of the Manila clam (Ruditapes philippinarum): Insights, threats, and control measures – A review

The Manila clam (Ruditapes philippinarum) is a pivotal species in global aquaculture; however, it faces substantial challenges due to parasitic infections. This comprehensive review discusses the diverse fauna affecting Manila clam populations, including viruses, bacteria, protozoans, metazoans, arthropods, and annelid taxa. Additionally, this review elaborates on the pathogenicity, geographical distribution, diagnostic methods, and investigation periods associated with these parasites. Notably, although some pathogens, such as Perkinsus olseni and Vibrio tapetis are widespread across multiple countries, others exhibit more localized distributions. The identification of World Organization for Animal Health (WOAH)-designated pathogens, such as P. olseni highlights the severity of the threats posed to Manila clam aquaculture and ecosystem health. Moreover, parasites not listed by WOAH, such as V. tapetis, Nymphonella tapetis, V. alginolyticus, and V. splendidus, pose substantial threats to Manila clam health and aquaculture sustainability, necessitating a holistic approach to understanding host–parasite dynamics. Globalization, rising sea temperatures, and environmental factors exacerbate the risk of pathogen introduction and spread, underscoring the need for proactive measures. Pathogen monitoring, risk assessment, and the development of diagnostic technology are crucial for effective disease management. Strengthening legal frameworks and infrastructure is essential to bolster quarantine and epidemic prevention measures and to ensure the long-term sustainability of Manila clam aquaculture.