Tridacna gigas

giant clam
Tridacna gigas
Tridacna gigas, 1 of 2. Coral Sea, QLD, Photo: Andrew Green
Tridacna gigas
Tridacna gigas, 2 of 2. Coral Sea, QLD, Photo: Andrew Green
Tridacna gigas
Tridacna gigas, 1 of 2. Coral Sea, QLD, Photo: Andrew Green
Tridacna gigas
Tridacna gigas, 2 of 2. Coral Sea, QLD, Photo: Andrew Green
Tridacna gigas
Tridacna gigas, 1 of 2. Raja Ampat, Indonesia, Photo: Andrew Green
Tridacna gigas
Tridacna gigas, 2 of 2. Raja Ampat, Indonesia, Photo: Andrew Green
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Tridacna gigas
Tridacna gigas
Tridacna gigas
Tridacna gigas
Tridacna gigas
Tridacna gigas

Distribution


Description

The largest of the giant clam species, attaining to 137cm long and 500kg. Usually free-living on either sand or hard reef substrata. Shell is elongate-oval to fan-shaped with a small byssal orifice. Upper shell margins exhibit distinctive elongate, triangular projections. Mantle mostly dull brown and olive green, with numerous hyaline organs along the mantle edge bordered by irridescent blue-green circles. Incurrent siphon bears no guard tentacles. 


Information

Max Size: 13700 cm

Sea Temperature Range: 23.4-30.7°C

Depth: N/A

Habitat Generalization Index: N/A

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.


Conservation and Rarity

IUCN Status: Vulnerable

Occurrence: Infrequent (7.9% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Few (2 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.