Tridacna derasa

giant clam
Tridacna derasa
Tridacna derasa, Tobias Reef, Queensland, Australia, 1 of 2, Photo: Andrew Green
Tridacna derasa
Tridacna derasa, Tobias Reef, Queensland, Australia, 2 of 2, Photo: Andrew Green
Tridacna derasa
Tridacna derasa, Coral Sea, Australia, Photo: Ian Shaw
Tridacna derasa
Tridacna derasa, Great Barrier Reef, Australia, Photo: Graham Edgar
Tridacna derasa
Tridacna derasa, Rowley Shoals, Western Australia, Photo: Graham Edgar
Tridacna derasa
Tridacna derasa, Flinders Reef, Coral Sea, Photo: Andrew Green
Tridacna derasa
Tridacna derasa, Swains Reefs, Coral Sea 1 of 2, Photo: Andrew Green
Tridacna derasa
Tridacna derasa, Swains Reefs, Coral Sea, 2 of 2, Photo: Andrew Green
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Tridacna derasa
Tridacna derasa
Tridacna derasa
Tridacna derasa
Tridacna derasa
Tridacna derasa
Tridacna derasa
Tridacna derasa

Distribution


Description

Very symmetrical and smooth shell with many (6-7) ribs; mantle hardly extends beyond shell. The definitive feature for T. derasa is the flat curves of the shell (i.e. wavelength along shell edge is much greater than amplitude), particularly towards the ends. Mantle pattern often contains thin streaks or lines.


Information

Max Size: 52 cm

Sea Temperature Range: 21.2-30.4°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: Frequent (15.2% 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.


Edit by: Andrew Green