Several rare sea snails were recently discovered around Cu Lao Cham Island off the coast of Hoi An City in central Quang Nam Province.
The snail species had not been seen for dozens of years, said Le Ngoc Thao, from Cu Lao Cham Marine Protected Area's Management Board.
Some of the snail species, such as Tu Va (Charonia tritonis), are listed in the Red Book of Viet Nam.
Thao said the return of the snails was due to the re-introduction of coral around the island.