ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Facts About Blue Sharks

Updated on February 1, 2013
blue shark
blue shark | Source

Blue sharks are to be found in every ocean and sea in the world, having the widest distribution of any shark species.

Members of the requiem shark family, they are classed as near threatened on the endangered species list, which is a misnomer if every I heard one.

All ‘near threatened’ means is that their numbers appear to have gone down in some parts of the world, though not necessarily in others.

Widespread studies are only now being carried out into shark behaviour and patterns, largely due to the invention and affordability of satellite technology, that allows sharks to be caught and tagged, and for monitoring stations to be planted on the sea bed to allow scientists to collate data.

While it is true that sharks are being fished to extinction, largely for that Chinese delicacy, shark’s fin soup, the actual numbers of most shark species have not been determined.

Blue sharks like swimming in cooler waters. While in the North Atlantic they are to be found swimming near the surface, in the tropical Indian or Pacific Oceans, they may be found at depths of 350 metres (over 1,000 feet).

Blue sharks are so widely distributed; they are to be found in the waters off every continent except Antarctica.

They tend to stay in deeper waters and not approach shorelines, unless there is an underwater continental shelf close to shore, as in the Red Sea.

world map showing the distribution of the blue shark
world map showing the distribution of the blue shark | Source

Are blue sharks dangerous?

Blue sharks are shy and nervous around people. Should you ever come face to face with a blue shark, any sudden movement on your behalf with see it shoot off into the darkness of the surrounding ocean.

Despite claims to the contrary, there have been no known reports of blue sharks attacking humans without provocation.

Check for yourself on the International Shark Attack files.

The only people who have been injured by blue sharks are fishermen and divers who attempted to spear and kill one.

When trapped, the blue shark will fight to the death. Even an apparently dead blue shark on a boat’s deck can whip its head round like lightning and bite the hand that touched it.

That is another weapon in their armoury. They can play dead too, so that your guard is down, then strike when you least expect it.

Unfortunately, beautiful blue sharks are frequently the target of sports fishermen who get their kicks from baiting and then hooking large sea creatures and reeling them in and out until the poor animal is exhausted and can finally be reeled on board.

Blue sharks are fish by the way, but in this case can be called animal, (as in animal, vegetable or mineral).

blue sharks
blue sharks | Source

Blue sharks ride the oceanic currents

Blue sharks are slow swimmers normally, but can put in bursts of speed when the situation requires it.

Did you ever watch the film Finding Nemo?

Do you remember how, in the movie, large tea turtles saved Marlin and Dory as they were riding the East Australian Current?

This is exactly what blue sharks spend their time doing. To the north of the equator, sea currents move west to east, and in the southern hemisphere, east to west.

Blue sharks must be thrill-seekers because this is how they travel round the world. They just climb on board, chill out and enjoy the ride!

Of course, this could be considered a form of relief for the blue shark, because as a species they are plagued by parasites that they can’t knock off.

Riding the major oceanic currents may well relieve the itchiness of parasitic infection, if it doesn’t actually knock them off.

Because short film about blue sharks getting caught and tagged

Blue sharks' life span and reproductive cycle

Blue sharks can grow to 12 feet long, and sometimes even bigger, but are generally around 4’ to 6’ in length. It is said they can live for 30 years, but we will know better in future thanks to studies being carried out now.

  • Female blue sharks reach sexual maturity at just 4 to 5 years old, which is exceptionally young for a shark.
  • Most sharks follow a similar pattern to humans, not maturing until they are in their teens at least.
  • Their pregnancies last for between 9 and 12 months, a figure which no doubt we will know exactly, one day soon.
  • Blue sharks are viviparous, meaning the eggs hatch in utero and the baby sharks are fed by a placental yolk sac, unlike many other species of shark who don’t provide nourishment at all, leaving the baby sharks, pups as they are known, to eat each other to survive.
  • Blue sharks commonly have litters of between 25 and 50 pups, but have been known to have as few as 4 and as many as 135.
  • They also give birth in nursery areas, normally warmer coastal waters where few predators live, giving the pups the greatest chance of survival.

One such known site in the south western Atlantic Ocean, near the southern coast of Brazil. There, juvenile blue sharks will remain until they are at least 1.3M (4 feet) in length.

Then, the male sharks head north, while the females swim south.

As the blue shark has frequently been spotted in groups of all female or all male, similarly sized fish, this extraordinary grouping by sex would seem to stem from some instinct they are born with.

An odd but worth noting fact about blue sharks is that the male bites the female to initiate sex.

As a result, female blue sharks have evolved to have a thick skin so that she is not harmed by the male's bites.

The video above briefly mentions this thick skin as the tags they use on the sharks go under the skin, apparently without causing pain.

blue shark
blue shark | Source

How to recognise a Blue Shark?

Blue sharks are long, slim, streamlined fish with rounded, elongated snouts and big eyes.

They are dark blue on top, light blue along the flank, and white underneath.

Probably their most distinguishing feature is their elongated pectoral fins – those are the ones at the sides.

Unless you are diving, or ship-wrecked in the middle of the ocean, you are unlikely to meet one.

There is some suggestion that blue sharks would eat you if you are injured and struggling in the ocean, but there is no proof of this.

You are more likely to get eaten by an oceanic whitetip shark, which you will instantly recognise from the white tips on its fins.

These are vicious predators which you wouldn’t wish on your worst enemy, but the blue shark is quite unlikely to take a bite unless you are dead or almost dead.

Should you ever be on vacation somewhere it is best to learn the name of the blue shark by its Latin name, Prionace glauca.

This is because other languages have different names for the blue shark, which in English is also known as blue dog and blue whaler, but in all languages it is called Prionace glauca.

It is estimated that 20 to 30 million blue sharks are killed every year by fishing.

While many of them are targeted for their fins, many more are caught in nets as an accidental by-catch.

Blue shark meat is not edible for long so their carcasses are mostly dumped.

It is only now that scientists are studying all sharks in detail, which should tell us more about these fascinating creatures.

The more we learn, the more we can find out how to save them from being fished out of existence.

Blue shark cartilage is often used in the alternative health market, promoting cancer-curing products that do not work.


    0 of 8192 characters used
    Post Comment
    • sharkfacts profile imageAUTHOR


      7 years ago from UK

      @Marcy, thanks, maybe I will do that someday :)

      @unknownspy, I think it's a shame to keep sharks in aquariums; in fact, they must be very unhappy which would make them more dangerous! They should be in the sea where they belong, and maybe we should stay out of the waters where they live. Blue sharks will not come near us anyway, even in the water.

    • unknown spy profile image

      Life Under Construction 

      7 years ago from Neverland

      Im scared of sharks.. We have an aquarium last time and my aunt bought 2 sharks..they're really scary. I loved reading your hub though..makes me aware of info and details about these creatures.

    • Marcy Goodfleisch profile image

      Marcy Goodfleisch 

      7 years ago from Planet Earth

      You could turn this and some of your other work into a book - excellent information and super interesting to read. I love the map, by the way!

    • sharkfacts profile imageAUTHOR


      8 years ago from UK

      Thanks jellygator. Blue sharks are amazing creatures.

    • jellygator profile image


      8 years ago from USA

      Voted up and beautiful.

    • sharkfacts profile imageAUTHOR


      8 years ago from UK

      You are right, I can see killing them if its you against them, but not for sport, and certainly not just for their fins.

    • CMHypno profile image


      8 years ago from Other Side of the Sun

      Interesting shark facts and you can't really blame them for attacking humans who are trying to kill them. Why is it that so many people seem to get pleasure from killing sharks and other large animals? If its for food that's different, but just to say you've done it or for a trophy is a bit sick.

    • sharkfacts profile imageAUTHOR


      8 years ago from UK

      Thanks, did you watch the videos? That was a brilliant piece of filming IMO. They put a shark cage out to protect the cameraman but he decided to leave the cage - just as well because a few minutes later a slim blue shark went in, straight through the bars, but couldn't get out again, till the diver helped it. If he had been in the cage at the time, it could bitten him as it would have felt trapped.

    • JKenny profile image

      James Kenny 

      8 years ago from Birmingham, England

      A great, detailed article. Packed full of information on a magnificent Shark. Voted up.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)