Small Giant Clam (Tridacna maxima) シラナミガイ also Common Giant Clam
Tridacna maxima usually only gets to about 30 cm which is small for a Giant Clam. They are often embeded in the coral or attached by a very strong and fibrous byssus. They have a great range in coloration. They do have a row of black dots around the margin of the shell. Amami
This Tridacna maxima is brown and in the coral. Amami
More detail on this Tridacna maxima. Miyakojima
This Tridacna maxima has some green to it. Miyakojima