 The genus "Magallana" is named for the Portuguese explorer Ferdinand Magellan and its specific epithet "gígās" is from the Greek for "giant".It was previously placed in the genus "Crassostrea;" from the Latin "crass" meaning "thick", "ostrea" meaning "oyster" 

The shell of "M. gigas" varies widely with the environment where it is attached.Its large, rounded, radial folds are often extremely rough and sharp.