Trivia: A video game from Sega in 1972 was called Killer Shark, considered the first video game in the horror genre. The object of the game was to shoot at a giant shark with harpoons. This game can be seen in the seaside arcade in the movie.
Trivia: Actor Robert Shaw took inspiration from and based his performance of Captain Quint on an eccentric, real-life Martha's Vineyard fisherman named Craig Kingsbury. Steven Spielberg was deeply impressed by Kingsbury, also, and actually cast him in the role of fisherman Ben Gardner. Beyond that, Kingsbury's colorful language around the set was often written into the dialogue of Captain Quint and Ben Gardner.
Trivia: The shark in the film was nicknamed Bruce - after Spielberg's attorney.
Trivia: The name Ben Gardner comes up in the film when Brody asks if Ben caught the tiger shark, and when Brody and Hooper find Ben's battered boat (which leads to Hooper seeing his severed head), though Ben is never introduced in the film. Ben does make two unidentified appearances while alive. When Hooper arrives in Amity, Ben is the first man to greet him at the dock, and at the start of the shark hunt Ben is the first man shown in a moving boat, as he complains about the other fishermen.
Trivia: When the three guys are out on the boat in the dark looking for the shark, a meteor shoots past Roy's right shoulder - this meteor was a real one. In the next few frames another meteor shoots across the top of the frame - this meteor was added in post-production.
Trivia: Brody's dog actually was the real life pet dog of Steven Spielberg.
Trivia: Throughout the filming, Robert Shaw and Richard Dreyfuss did not like each other and they often argued on set. This actually helped create some good tension between their characters.
Trivia: Brody's line, "You're gonna need a bigger boat", was actually a total ad-lib. The director wanted a real reaction to the shark popping up really close to him, so they didn't tell Roy Scheider that it was going to happen. It was a total surprise. Not only did he react naturally, it scared him so badly that he forgot the correct line. So, when he looked at Quint, he ad-libbed, and they left it in the movie. (It was number 35 on the top 100 Most Memorable Movie Quotes list).
Trivia: When the girl is being attacked, she seems to do an incredible job of acting in pain. The thing is, she is not acting. The scene was done with divers under the water pulling the actress with ropes, hard enough to bruise her.
Trivia: The shark doesn't make its first full appearance until 81 minutes into the movie, and only has four minutes of screen time.
Trivia: During the scene where Dreyfus' character is underwater in a protective case, Spielberg used a real shark, which was much smaller than the mechanical shark. They were going to use a little person to stand in for Dreyfus but it was too dangerous, so they used a small mannequin.
Trivia: Matt Hooper was originally supposed to die. After the infamous incident where the real shark was caught in the wires above the miniature cage, the midget actor refused to go back in the water with it, meaning the filmmakers had to rewrite the script for Hooper to survive.
Trivia: Richard Dreyfuss initially turned down the role of Hooper, but after worrying that no one would hire him after his performance in the film "The Apprenticeship of Duddy Kravitz", he immediately called director Steven Spielberg and asked for the part back.
Trivia: Throughout the movie the color yellow runs as a theme. Yellow is known as a color that sharks can actually see, which is why lifeboats should not be painted in that color.
Trivia: When Mrs Kintner sees Chief Brody at the dock, she says "Chief Brody?" and slaps him. Roy Scheider was actually hit in the face, as Lee Fierro was apparently unable to fake the slap.
Trivia: Steven Spielberg has referred to Bruce as being a "floating turd" in interviews. You can see his point when you see the shark in full length for the first time.
Answer: Possibly a scar from having his appendix removed, I've been told.
The appendix shot is Brody - he is feeling inferior as the other two share tales of the sea and the only scar he has is from his appendix being removed.