{"id":39726,"date":"2025-06-19T10:45:00","date_gmt":"2025-06-19T10:45:00","guid":{"rendered":"https:\/\/www.lifeandnews.com\/articles\/?p=39726"},"modified":"2025-06-19T04:06:04","modified_gmt":"2025-06-19T04:06:04","slug":"50-years-after-jaws-researchers-have-retired-the-man-eater-myth-and-revealed-more-about-sharks-amazing-biology","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/50-years-after-jaws-researchers-have-retired-the-man-eater-myth-and-revealed-more-about-sharks-amazing-biology\/","title":{"rendered":"50 years after \u2018Jaws,\u2019 researchers have retired the man-eater myth and revealed more about sharks\u2019 amazing biology"},"content":{"rendered":"\n
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The shark in \u2018Jaws\u2019 became a terrifying icon. Universal Pictures via Getty Images<\/a><\/figcaption><\/figure>\n\n\n\n

Gareth J. Fraser<\/a>, University of Florida<\/a><\/em><\/p>\n\n\n\n

The summer of 1975 was the summer of \u201cJaws<\/a>.\u201d<\/p>\n\n\n\n

\"movie
The movie was adapted from a novel by Peter Benchley. Universal History Archive\/Universal Images Group via Getty Images<\/a><\/figcaption><\/figure>\n\n\n\n

The first blockbuster movie<\/a> sent waves of panic and awe through audiences. \u201cJaws\u201d \u2013 the tale of a killer great white shark that terrorizes a coastal tourist town \u2013 captured people\u2019s imaginations and simultaneously created a widespread fear of the water.<\/p>\n\n\n\n

To call Steven Spielberg\u2019s masterpiece a creature feature is trite. Because the shark isn\u2019t shown for most of the movie \u2013 mechanical difficulties meant production didn\u2019t have one ready to use<\/a> until later in the filming process \u2013 suspense and fear build. The movie unlocked in viewers an innate fear of the unknown, encouraging the idea that monsters lurk beneath the ocean\u2019s surface, even in the shallows.<\/p>\n\n\n\n

And because in 1975 marine scientists knew far less than we do now about sharks and their world, it was easy for the myth of the rogue shark as a murderous eating machine to take hold, along with the assumption that all sharks must be bloodthirsty, mindless killers.<\/p>\n\n\n\n

\"moviegoers
People lined up to get scared by the murderous shark at the center of the \u2018Jaws\u2019 movie. Bettmann Archive via Getty Images<\/a><\/figcaption><\/figure>\n\n\n\n

But in addition to scaring many moviegoers that \u201cit\u2019s not safe to go in the water,\u201d \u201cJaws\u201d has over the years inspired generations of researchers, including me<\/a>. The scientific curiosity sparked by this horror fish flick has helped reveal so much more about what lies beneath the waves than was known 50 years ago. My own research focuses on the secret lives of sharks, their evolution and development, and how people can benefit from the study of these enigmatic animals.<\/p>\n\n\n\n

The business end of sharks: Their jaws and teeth<\/h2>\n\n\n\n

My own work<\/a> has focused on perhaps the most terrifying aspect of these apex predators, the jaws and teeth. I study the development of shark teeth in embryos.<\/p>\n\n\n\n

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Small-spotted catshark embryo (Scyliorhinus canicula<\/em>), still attached to the yolk sac. This is the stage when the teeth begin developing. Ella Nicklin, Fraser Lab, University of Florida<\/figcaption><\/figure>\n\n\n\n

Sharks continue to make an unlimited supply of tooth replacements throughout life \u2013 it\u2019s how they keep their bite constantly sharp.<\/p>\n\n\n\n

Hard-shelled prey, such as mollusks and crustaceans, from sandy substrates can be more abrasive for teeth, requiring quicker replacement. Depending on the water temperature, the conveyor belt-like renewal of an entire row of teeth can take between nine and 70 days, for example, in nurse sharks<\/a>, or much longer in larger sharks. In the great white, a full-row replacement can take an estimated 250 days. That\u2019s still an advantage over humans \u2013 we never regrow damaged or worn-out adult teeth.<\/p>\n\n\n\n

\"about
Magnified microscope image of a zebra shark (Stegostoma tigrinum<\/em>) jaw. They have 20 to 30 rows of teeth in each jaw, each a new generation ready to move into position like on a conveyor belt. Humans have only two sets! Gareth Fraser, University of Florida<\/figcaption><\/figure>\n\n\n\n

Interestingly, shark teeth are much like our own, developing from equivalent cells, patterned by the same genes<\/a>, creating the same hard tissues, enamel and dentin<\/a>. Sharks could potentially teach researchers how to master the process of tooth renewal. It would be huge for dentistry if scientists could use sharks to figure out how to engineer a new generation of teeth for human patients.<\/p>\n\n\n\n

Extraordinary fish with extraordinary biology<\/h2>\n\n\n\n

As a group, sharks and their cartilaginous fish relatives \u2013 including skates, rays and chimaeras \u2013 are evolutionary relics that have inhabited the Earth\u2019s oceans for over 400 million years<\/a>. They\u2019ve been around since long before human beings and most of the other animals on our planet today hit the scene, even before dinosaurs emerged.<\/p>\n\n\n\n

Sharks have a vast array of super powers that scientists have only recently discovered.<\/p>\n\n\n\n

Their electroreceptive pores, located around the head and jaws, have amazing sensory capabilities, allowing sharks to detect weak electrical fields<\/a> emitted from hidden prey.<\/p>\n\n\n\n

\"looks
CT scan of the head of a small-spotted catshark (Scyliorhinus canicula<\/em>) as it hatches. Skin denticles cover the surface, and colored rows of teeth are present on the jaws. Ella Nicklin, Fraser Lab, University of Florida<\/figcaption><\/figure>\n\n\n\n

Their skin is protected with an armor of tiny teeth, called dermal denticles, composed of sensitive dentin<\/a>, that also allows for better drag-reducing hydrodynamics. Biologists and engineers are also using this \u201cshark skin technology<\/a>\u201d to design hydrodynamic and aerodynamic solutions for future fuel-efficient vehicles.<\/p>\n\n\n\n

\"green
Fluorescent skin of the chain catshark (Scyliorhinus retifer<\/em>). Gareth Fraser, University of Florida<\/figcaption><\/figure>\n\n\n\n

Some sharks are biofluorescent<\/a>, meaning they emit light in different wavelengths after absorbing natural blue light. This emitted fluorescent color pattern suggests visual communication and recognition among members of the same species is possible in the dark depths.<\/p>\n\n\n\n

Sharks can migrate<\/a> across huge global distances<\/a>. For example, a silky shark<\/a> was recorded<\/a> traveling 17,000 miles (over 27,000 kilometers) over a year and a half. Hammerhead sharks can even home in on the Earth\u2019s magnetic field<\/a> to help them navigate.<\/p>\n\n\n\n

Greenland sharks exhibit a lengthy aging process and live for hundreds of years<\/a>. Scientists estimated that one individual was 392 years old<\/a>, give or take 120 years.<\/p>\n\n\n\n

Still much about sharks remains mysterious. We know little about their breeding habits and locations of their nursery grounds<\/a>. Conservation efforts are beginning to target the identification of shark nurseries<\/a> as a way to manage and protect fragile populations.<\/p>\n\n\n\n

Tagging programs<\/a> and their \u201cfollow the shark\u201d apps<\/a> allow researchers to learn more about these animals\u2019 lives and where they roam \u2013 highlighting the benefit of international collaboration and public engagement for conserving threatened shark populations.<\/p>\n\n\n\n

Sharks under attack<\/h2>\n\n\n\n

Sharks are an incredible evolutionary success story. But they\u2019re also vulnerable in the modern age of human-ocean interactions.<\/p>\n\n\n\n

Sharks are an afterthought for the commercial fishing industry, but overfishing of other species can cause dramatic crashes in shark populations<\/a>. Their late age of sexual maturity<\/a> \u2013 as old as 15 to 20 years or more in larger species or potentially 150 years in Greenland sharks \u2013 along with slow growth, long gestation periods and complex social structures make shark populations fragile and less capable of quick recoveries.<\/p>\n\n\n\n

Take the white shark<\/a> (Carcharodon carcharias<\/em>), for example \u2013 Jaws\u2019 own species. Trophy hunting, trade in their body parts and commercial fishery impacts caused their numbers to dwindle<\/a>. As a result, they received essential protections<\/a> at the international level. In turn, their numbers have rebounded, especially around the United States, leading to a shift from critically endangered to vulnerable status worldwide. However, they remain critically endangered in Europe and the Mediterranean.<\/p>\n\n\n\n

\"shark
Protections and conservation measures have helped white sharks make a comeback. Dave Fleetham\/Design Pics Editorial\/Universal Images Group via Getty Images<\/a><\/figcaption><\/figure>\n\n\n\n

\u201cJaws\u201d was filmed on the island of Martha\u2019s Vineyard, in Massachusetts. After careful management and the designation of white sharks as a prohibited species<\/a> in federal waters in 1997 and in Massachusetts in 2005, their populations have recovered well over recent years in response to more seals in the area and recovering fish stocks.<\/p>\n\n\n\n

You might assume more sharks would mean more attacks, but that is not what we observe. Shark attacks<\/a> have always been few and far between in Massachusetts and elsewhere, and they remain rare. It\u2019s only a \u201cJaws\u201d-perpetuated myth that sharks have a taste for humans. Sure, they might mistake a person for prey; for instance, surfers and swimmers can mimic the appearance of seals at the surface. Sharks in murky water might opportunistically take a test bite<\/a> of what seem to be prey.<\/p>\n\n\n\n

But these attacks are rare enough<\/a> that people can shed their \u201cJaws\u201d-driven irrational fears of sharks. Almost all sharks are timid, and the likelihood of an interaction \u2013 let alone a negative one \u2013 is incredibly rare. Importantly, there more than 500 species of sharks<\/a> in the world\u2019s oceans, each one a unique member of a particular ecosystem with a vital role<\/a>. Sharks come in all shapes and sizes, and inhabit every ocean, both the shallow and deep-end ecosystems.<\/p>\n\n\n\n

Most recorded human-shark interactions are awe-inspiring and not terrifying. Sharks don\u2019t really care about people \u2013 at most they may be curious, but not hungry for human flesh. Whether or not \u201cJaws\u201d fans have grown beyond the fear of movie monster sharks, we\u2019re gonna need a bigger conservation effort to continue to protect these important ocean guardians.<\/p>\n\n\n\n

Gareth J. Fraser<\/a>, Associate Professor of Evolutionary Developmental Biology, University of Florida<\/a><\/em><\/p>\n\n\n\n

This article is republished from The Conversation<\/a> under a Creative Commons license. Read the original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Gareth J. Fraser, University of Florida The summer of 1975 was the summer of \u201cJaws.\u201d The first blockbuster movie sent waves of panic and awe through audiences. \u201cJaws\u201d \u2013 the tale of a killer great white shark that terrorizes a coastal tourist town \u2013 captured people\u2019s imaginations and simultaneously created a widespread fear of the […]<\/p>\n","protected":false},"author":56,"featured_media":39728,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[5,279,7,10,25,39,118],"tags":[16538,885,891,886,860,756,16540,16539,16541,2801],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/39726"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/56"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=39726"}],"version-history":[{"count":2,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/39726\/revisions"}],"predecessor-version":[{"id":39729,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/39726\/revisions\/39729"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/39728"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=39726"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=39726"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=39726"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}