Tridacna gigas (Giant Clam) Care Guide
Tridacna gigas is the largest living bivalve, an Indo-Pacific reef giant suited only to public aquariums and protected by CITES.
Overview
Tridacna gigas is the largest living bivalve mollusc. It can reach a maximum length of about 137 cm, typically measuring as much as 120 cm across, and a specimen found in 1956 weighed 333 kg dead. Adults cannot fully close their shells, leaving part of the brownish-yellow mantle visible, and the shell bears four or five vertical folds.
Taxonomy
- Family: Cardiidae
- Subfamily: Tridacninae
- Genus: Tridacna
- Scientific name: Tridacna gigas
Habitat
Its range covers the Indo-Pacific, with populations on coral reefs of the South Pacific and Indian Oceans. It is found at depths of as great as 20 m on flat coral sand or broken coral.
Diet
About 65-70 percent of its nutritional needs are supplied by symbiotic zooxanthellae cultivated in specialised tissues, which enables it to grow to one metre in length despite nutrient-poor reef waters. The remainder is obtained through filter feeding.
Lifespan
The average lifespan exceeds 100 years in the wild.
Aquarium note
Because of its enormous adult size, Tridacna gigas is realistic only at public-aquarium scale and is not suited to home tanks. It is listed here for completeness.