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Giant Pacific Clam

Tridacna gigas


Interior comes in a wide range of colours, I saw blues, purples, greens and browns. They can grow up to 200kg and 1.2m across. They are easy to spot when the bivalve is open, identifiable by the and wavy line. Their huge growth is the result of a symbiotic relationship with algae living inside the clam's shell that feeds off the clam's waste, while the clams take in carbohydrates produced through photosynthesis by the algae. They are also filter feeders. The myriad of colours on their insides is due to the iridocytes which . The iridocytes diffuse light into the clam. This one was about 7cm long and 2.5cm wide


Their habitat range is huge. It goes from North China, all through the Pacific, to the Cook Islands and Niue. They like to nestle themselves in ocean beds or broken coral. Their deepest comfortable depth is 20m. These juveniles were wedged in limestone crevasses in less than 10cm of water.

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Spotted on Aug 19, 2017
Submitted on Aug 19, 2017

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