The 40<sup>th anniversary of the initial release of Jaws is marked on 1 June 1975, striking a fear of sharks into a whole generation to follow. It opened in cinemas across the US a few weeks later and would go on to become the highest grossing film of the time.

To mark the event, IBTimes UK has looked at some facts and figures about Stephen Spielberg's infamous movie.

1. The great white shark in the film was estimated to be around 25ft long. The biggest great white to have ever been caught in real life was around 20ft.

2. The film was based on the book by Peter Benchley. He based it on a series of shark attacks that took place off the coast of New Jersey in 1964 and a 4,500lb shark caught in 1964 off the coast of Montauk.

3. Other titles for the bestseller included The Silence of the Deep, Leviathan Rising, and The Jaws of Death.

4. Despite widespread belief, stunt woman and actress Susan Backlinie did not break her ribs or hip while filming the opening scene, meaning her screams of terror were real. However, Spielberg did not warn her when she would be 'attacked', so her reactions were more genuine.

5. Richard Dreyfuss was not Spielberg's first choice for the role of Matt Hooper – Jeff Bridges, Timothy Bottoms and Jon Voight were all approached first.

6. The iconic poster for Jaws was designed by artist Roger Kastel for Benchley's book.

7. In the book, Hooper dies and Quint is killed by drowning – he is dragged underwater after harpooning jaws. In the film, Hooper lives and Quint is eaten alive feet-first.

8. On set, Robert Shaw (Quint) and Dreyfuss (Hooper) did not like each other, providing some of the tension between the pair.

9. Five people are killed by jaws in the film – Chrissie Watkins, Alex Kinter, Ben Gardner, a man in the estuary and Quint. A dog also died.

10. Spielberg initially did not like the music saying it was too simple. He changed his mind later.

11. Credited with being the first summer "blockbuster" after over 67 million people in the US went to see it.

12. Jaws made over $7m in its opening weekend – not far off the $9m production budget.

13. Three mechanical sharks were used in the filming with each having specialised functions. They were nicknamed "Bruce" after Spielberg's lawyer.

14. The first shark killed in the film was a real shark killed in Florida.

15. The film's most famous line – "We're gonna need a bigger boat" – was improvised by Roy Schnieder.

16. When the first victim's hand is found in the sand, Spielberg said the fake arm they had bought looked too fake, so they buried a crew member in the sand with her arm sticking out.

17. Fidel Castro enjoyed Jaws and considered a wonderful piece of Marxist propaganda. He said he thought the shark was attacking American culture and capitalism.

18. Brody's dog in the film was Spielberg's dog in real life – Elma.

19. Spielberg was not the original choice for director. The first choice was scrapped because they did not know the difference between a whale and a shark.

20. The first mechanical shark was not tested in water before production started and when it was placed in the ocean it sank to the floor.

21. Charlton Heston wanted to play the role of Brody and when Spielberg turned him down, he vowed never to work with the director.

22. Jaws is credited with vilifying sharks, creating a perception of them being dangerous killers.

23. Shark expert George Burgess told National Geographic that the film initiated a huge decline in US shark populations with thousands setting out to catch them as trophies.

24. The books' author Benchley went on to become a conservationist and became filled with regret for having written Jaws. He said, "knowing what I know now, I could never write that book today".

25. On average, five people are killed by sharks every year, with around 75 attacks in total globally.

26. More than 100 million sharks are killed by humans every year.

27. In the 1970s and 1980s, Great White Shark populations in the northwest Atlantic had plummeted by around 70% since 1961 levels.

28. In 1997, a US federal law was introduced banning the hunting of great white sharks.

29. In 2013, a South African fisherman became the first person to be prosecuted for hunting a great white – it had been illegal there since 1991.

30. Around a quarter of Jaws was filmed from water level to give the audience the perspective of treading water.

31. In reality, sharks do not like eating humans because we are too bony – we are not seen as being nutritious enough to be worth the effort.

32. Most shark attacks are the result of test bites – after an initial taste, they normally won't return, which is why most attacks are not fatal.

33. The great white was is thought to have been chosen to represent Jaws because it is the only species of shark that can stick its head above water to look for prey.

34. Popularised the film technique of the 'dolly zoom' filmmakers use to give the sensation of vertigo.

35. Jaws won three Oscars – Best Sound, Best Film Editing and Best Music, Original Dramatic Score. Spielberg won a Golden Globe as Best Director for it.

37. Jaws does not appear in a shot fully until an hour and 21 minutes into the film – which is just two hours long. This is because the mechanical shark rarely worked, not as a ploy to build tension.

38. Spielberg did not direct the final shot of the shark exploding – he had returned to Los Angeles to begin post production and left the scene to the second unit.

39. Benchley was not happy with the ending and was thrown off the set as a result. He said the explosion was unrealistic, to which Spielberg replied the audience would believe anything after two hours.

40. The chance of being killed by a shark is one in 3.7 million.