The habitat of giant clams is mainly in the coral reefs of the Pacific and Indian Oceans. In Vietnam, the giant clams belong to three species: 𝘛𝘳𝘪𝘥𝘢𝘤𝘯𝘢 𝘴𝘲𝘶𝘢𝘮𝘰𝘴𝘢, 𝘛. 𝘤𝘳𝘰𝘤𝘦𝘢, and 𝘛. 𝘮𝘢𝘹𝘪𝘮𝘢 (Nguyen et al., 2011b, 2011a; Nguyen and Dang, 2014).
Giant clams play multiple roles in coral reef ecosystems. They help build coral reefs, provide food and shelters to fish and crustaceans. With filter-feeding properties similar to other bivalve molluscs, giant clams act as a “biofilter” to help improve the habitat around coral reefs. (Neo et al., 2015).
Because of their values and eye-catching colors, giant clams are often hunted for meat, shells and used in marine aquariums. This causes the number of giant clams in the world to decrease. The average lifespan of a giant clam can be up to 100 years. But in the face of climate change and polluted habitats, it is likely that the giant clams will become extinct in the future.
Currently, some species of the giant clams (genus 𝘛𝘳𝘪𝘥𝘢𝘤𝘯𝘢) are listed in the IUCN Red List as vulnerable species. A number of hatcheries and operations for giant clams have been established in the Pacific and the Indian Ocean regions with the aim of conserving the species and regenerating coral reefs (John, 2003).