Giant clams are among the most charismatic of sea creatures. They are an important human food in their natural environment and they are highly prized for display in marine aquariums. Many species have become locally extinct due to overharvesting and giant clam species are an internationally protected group.

Giant clams grow to become the heaviest of all bivalves. They have a strongly curved shell which features anywhere from three to eight radial folds. The folds form a toothy gap where the shells meet. Giant clams have a colorful mantle protruding through the shell which can be deep or elecric blue, brown, golden, black and combinations thereof. The mantle features an incurrent and excurrent siphon and a row of tiny 'eyes' on the edge called iridophores.

Tridacnids derive their food from light and filter feeding. T. crocea and T. maxima require strong light intensity but T. squamosa and T. derasa can make due with slightly reduced light levels. T. gigas and Hippopus species will do well in a range of light intensities. Although clams can derive all of their energy requirements from light, they still require filter feeding to obtain necessary fats and proteins.

Sexual reproduction of giant clams in captivity is an involved, large scale process suited only for commercial operations.