What was the name given to the mechanical sharks used in the 1975 hit movie "Jaws"?

"Jaws" is a 1975 American thriller film directed by Steven Spielberg and based on Peter Benchley's 1974 novel of the same name. In the story, a giant man-eating great white shark attacks beachgoers on Amity Island, a fictional New England summer resort town, prompting the local police chief to hunt it with the help of a marine biologist and a professional shark hunter. The film stars Roy Scheider as police chief Martin Brody, Robert Shaw as shark hunter Quint, Richard Dreyfuss as oceanographer Matt Hooper, Murray Hamilton as Larry Vaughn, the mayor of Amity Island, and Lorraine Gary as Brody's wife, Ellen. The screenplay is credited to both Benchley, who wrote the first drafts, and actor-writer Carl Gottlieb, who rewrote the script during principal photography.

Three full-size pneumatically powered prop sharks (which the film crew nicknamed "Bruce" after Spielberg's lawyer, Bruce Ramer) were made for the production. A "sea-sled shark", a full-body prop with its belly missing that was towed with a 300 feet (91 m) line, and two "platform sharks", one that moved from camera-left to -right (with its hidden left side exposing an array of pneumatic hoses), and an opposite model with its right flank uncovered. The sharks were designed by art director Joe Alves during the third quarter of 1973.