Derrrr-dun,derrr-dun, derdunderdunderdun. That rumbling two-note refrain from Jaws is, like the shower scene in Psycho, instantly evocative of fear.
The 1975 film tapped straight into our enduring fascination with, and fear of, the unknown. It became the biggest grossing movie in cinema history - until Star Wars came along two years later - and set director Steven Spielberg on his way to greatness. But its protagonist, the great white shark, didn't come out so well.
Portrayed as a kind of psychopathic monster, he got the kind of character mauling that would have any upstanding citizen phoning their solicitor the moment the credits rolled.
If we know little about great white sharks now, we knew even less then - even though they have been around for 400 million years. As their bodies are made of cartilage, not bone, they leave no skeleton, and we can learn about their history only from what remains, the teeth. We know that the great white shark can be predatory and solitary - the five-foot babies fend for themselves almost from the moment they are born; huge, growing to more than 2,000kg and 10 metres in length; ferocious and voracious.
Now another adjective can be added to the list: endangered. The great white is one of four shark species under threat and protected by the governments of some countries, including the United States. But because their status is recognised by only a few countries and they are migratory creatures, this protection is only partial.
Modern fishing methods mean some great whites endup like this one, trawled from the sea off California, after being caught in drift nets. Dubbed "walls of death", the nets are up to a mile long and hang down 80 to 100 feet.
It's recognisably the same gaping, razor-toothed mouth that snarled down from Jaws posters, but bloody, like the loser in a fight.
Shark attacks make good disaster movies and great headlines, but they are seldom fatal. According to the US International Shark Attack File, there have been 245 attacks on humans by great whites in the past 125 years, but only 64 of them have been fatal.
When they hunt, great whites use pores on their heads to pick up tiny electrical charges emitted by their prey, and the super-sensitive olfactory cells that line their nostrils to sniff them out. They can accelerate to 25 miles per hour, hitting their victim from below, mouth wide open, clamping shut at the first impact.
The great white's jaws are sensitive to the fat content of its prey and it prefers the blubbery flesh of seals and sea-lions to humans, usually releasing us after sensing its mistake - known as the thump, bite and spit method of chasing the menu.
Peter Benchley, the author of Jaws who now campaigns for shark conservation, admits that his portrayal was inaccurate. He says: "My fear has been turned into respect."
As more and more great whites are slaughtered each year, that ominous film score is beginning to sound more and more like a requiem.
Web links conservation group: www.wildaid.org Site for shark fans: www.greatwhite.org About the film: www.jawsmovie.com