Sergio Island

Sergio Island was a volcanic South Pacific island under development by a Japanese corporation to turn it into a tourist resort, with some limited cooperation from the natives. When Yog took command of Helios 7, the space probe crashlanded in the waters off of Sergio's shores and the alien(s) subsequently took over the bodies of a cuttlefish, two crabs and a turtle as the beginning of their attempt to conquer the world.

Commentary

The island is named for director Sergio Leone, as Leone's films were popular at the time Space Amoeba was made. This in-joke however is lost in most English translations of the film, which, under the assumption that most R's in the Japanese language are supposed to be L's, change the island's name to "Selgio Island." This is how its name appears in written form in subtitled versions of the movie.