The giant clam, known for its colorful cape-like mantle, wavy shell and astonishing size, is in danger of going extinct after its population plunged by more than 80% over the last century, according to a new assessment by a CU Boulder biologist and collaborators. The giant clam, known for its colorful cape-like mantle, wavy shell and astonishing size, is in danger of going extinct after its population plunged by more than 80% over the last century, according to a new assessment by a CU Boulder biologist and collaborators. Plants & Animals Ecology Phys.org – latest science and technology news stories