Common name: Giant clam

General information

The Giant Clam, Tridacna gigas, is one of the most impressive invertebrates found in the reef aquarium hobby. Known for its immense size, it can grow up to 4 feet in length and weigh over 500 pounds in the wild, making it the largest bivalve mollusk in the world. These clams are also known for their vibrant and colorful mantles, which contain symbiotic photosynthetic algae, zooxanthellae, that provide nutrients through photosynthesis.

Care

Giant Clams require intense lighting to thrive in captivity due to their symbiotic relationship with zooxanthellae. They also need stable water conditions with high levels of calcium and trace elements to support their shell growth. It's important to provide them with a sandy substrate or a place where they can anchor themselves securely.

Reproduction

In the wild, Tridacna gigas reproduce through broadcast spawning, where eggs and sperm are released into the water column. In captivity, breeding Giant Clams is a complex process typically done in specialized facilities.

Symbiosis

Tridacna gigas has a mutualistic relationship with zooxanthellae algae, which live within the clam's mantle tissue. The algae provide the clam with nutrients from photosynthesis, while the clam offers a protected environment and the compounds necessary for photosynthesis.

Habitat

Giant Clams are native to the warm waters of the Indo-Pacific region. They are typically found in shallow coral reefs where sunlight is abundant for their symbiotic algae to perform photosynthesis effectively.