Common name: Bear paw clam

General information

The Giant Clam, Hippopus hippopus, also known as the Bear Paw Clam, is a large bivalve mollusk known for its impressive size and beautifully colored mantle. This species is a member of the Tridacninae subfamily and is one of the larger clam species popular in the reef aquarium hobby. The mantle of the Giant Clam contains symbiotic zooxanthellae, which provide the clam with nutrients through photosynthesis and contribute to its vibrant colors.

Care

Giant Clams require intense lighting to support the photosynthetic needs of their symbiotic algae. They should be placed on stable substrates where they can attach their byssal threads securely. Water quality is paramount, with stable calcium and alkalinity levels being crucial for shell growth. They are filter feeders and will benefit from supplemental feeding of phytoplankton or other fine particulate foods.

Reproduction

In the wild, Giant Clams are broadcast spawners, releasing eggs and sperm into the water column where fertilization occurs. In the aquarium, breeding Giant Clams is challenging and typically not feasible for most hobbyists due to the large space and specific environmental conditions required.

Symbiosis

The symbiotic relationship between the Giant Clam and its zooxanthellae is a classic example of mutualism. The clam provides a safe habitat and nutrients for the algae, while the algae reciprocate by supplying the clam with organic compounds produced through photosynthesis.

Habitat

Giant Clams are found in shallow, warm waters of the Indo-Pacific region. They prefer reef environments where they can anchor themselves to substrates and receive ample sunlight for their symbiotic algae.