Giant clam, Tridacna gigas, this enormous shellfish is the largest species of bivalve mollusc in the fossil record, and the heaviest of all the living molluscs, about 300KG.
Giant clams have been extensively harvested for their meat and to supply the aquarium trade with such exotic specimens. Unable to sustain this exploitation, populations are now showing signs of decline; Tridacna gigas have not been seen in Fiji for over 50 years, primarily as a result of past over-collection for food.
hese clams are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which requires a permit to be granted before giant clams can be exported. There has been considerable success with farming, which may help to alleviate the pressure on wild populations in the long-term. Farmed clams may also be used in restocking programmes, where numbers have become severely restricted in the wild. Giant clams were reintroduced to Tongan waters in 1990, from quarantined-reared stocks cultured in Australia under the Australian Centre for International Agricultural Research and James Cook University giant clam project. These enormous molluscs have inspired awe for centuries and effective protection measures are vital if they are to be adequately conserved for future generations.