Gigas Clam

The Gigas Clam (Tridacna gigas). It is a peaceful species that is reef-safe, admired for its immense size, beautiful mantle coloration, and unique patterned iridescence.

Males typically cannot be visually distinguished, as clams are simultaneous hermaphrodites—they can release sperm first and then eggs—but in general terms, juveniles function as males and, as they grow, they gain female reproductive capability.

They reach about 47 inches (120 cm) in the wild, though in aquariums usually much smaller (commonly 12–24 inches). They should be housed in aquariums of at least 250 gallons or more, as they grow continuously throughout life.

Provide a deep sandbed or stable flat rock base for secure attachment, ample light exposure (strong reef lighting, since they rely heavily on symbiotic zooxanthellae), and stable water parameters: salinity 1.020–1.025, temperature 72–79°F, and pH 8.1–8.4. Unlike fish, they do not require a lid, but they do need protection from predators and strong water movement.

Diet should consist primarily of photosynthesis from their symbiotic algae (zooxanthellae), supplemented in juveniles with phytoplankton, marine snow, or specialized filter-feeding foods. With proper care, this clam becomes a majestic centerpiece in large reef aquariums.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.