Giant Clam
A spectacular reef bivalve that can be enormous and brightly colored.
- Local name: Kima
- Scientific name: Tridacna spp.
Giant clams are among the most visually striking creatures on shallow reefs — massive bivalves embedded in coral rock with vibrant, wavy mantles in blues, greens, and purples. They filter-feed and host symbiotic algae in their tissue, keeping their mantles open to sunlight.
Key facts
- Habitat
- Shallow coral reefs and reef flats
- Diet
- Filter-feeding plus symbiotic algae
- Size
- Up to 1.2 meters
- Behavior
- Sessile; mantle open in sunlight; closes when disturbed
Where to see it
Found in shallow coral gardens and reef flats where sunlight reaches the bottom, typically 1-8 meters deep. Look for them embedded in coral bommies or nestled into reef structure — the bright mantles stand out against coral and rock.
How to spot it
Scan shallow reef areas for thick, scalloped shells with colorful tissue exposed. The mantle pulses gently and will close if you approach too quickly or cast a sudden shadow. Move slowly and they'll stay open for observation.
Watching responsibly
- Never touch the mantle — contact stresses them and can cause permanent damage.
- Stay off the reef to photograph — don't stand on coral for a better angle.
- Leave them where they are — they're protected and slow-growing.
- Keep your fins controlled to avoid stirring sediment that settles on their tissue.
Conservation
Some species Critically Endangered due to overharvest and habitat decline.
Ready to see it for yourself?
Our cruises run from Luwuk through the Togean archipelago. Check the departure schedule, or message us and we'll help you pick the trip that fits.