Skip to main content
Snails

Invertebrate · Least Concern

Snails

Tridacna maxima

About

Tridacna maxima, the maxima or small giant clam, is a bivalve mollusc found throughout the Indo-Pacific region.

Family
Cardiidae
Avg size
20-35 cm
Habitat
This clam has the broadest range of any giant clam, occurring around East Africa, India, China, Australia, Southeast Asia, the Red Sea, and the Pacific islands. It settles on reef surfaces or sand, or partly embedded in coral, and keeps to well-lit areas because the photosynthetic algae it depends on need sunlight.
Behaviour
A sessile mollusc, the small giant clam anchors itself to rock or dead coral and draws water through its body, filtering out phytoplankton and taking up oxygen through its gills. It needs to filter-feed far less than other clams, however, since most of its nourishment comes from symbiotic photosynthetic algae called zooxanthellae. It begins life as a fertilised egg that hatches within 12 hours into a free-swimming larva; this develops into a more advanced larva capable of filter-feeding, and by the third larval stage a foot appears, letting it alternate between swimming and resting on the seabed.

Where & when

Where & When to See It

More Invertebrates