chapter 9

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I have studied about sharks last few weeks . Most people known sharks as dangerous animals , It's little bit wrong because all sharks are isn't dangerous so I hope this chapter will helpful for you to forget misunderstand about them .

Sharks . The name alone instils fear . These ancient beings have combed the depths since before the dinosaurs , placing them among the most fascinating creatures beneath the waves . Why then do they attract such stigma ? And should we really be scared of them ? Ever since Spielberg's Jaws hit the big screen in 1975 , sharks have attracted more fear than they have fascination - with myths and half-truths gaining attention ahead of facts and conservation . But with shark numbers now in sharp decline, it's time to get wise to these amazing creatures before it's too late . To help , I put together a guide on everything you need to know about sharks , so you can get to grips with just how wonderful and valuable they really are .

First : sharks are fish . Given the size of some species of shark , it's easy to see why some people mistake them for mammals , but they are indeed fish - albeit , very big ones ! The simplest way to determine a shark's fish pedigree is to note the gills just in front of the pectoral fins on the side of their body . As with al fish , these gills take in water , forcing it through lots of tiny blood vessels . These vessels absorb oxygen from the water , allowing sharks to breathe underwater without rising to the surface .

Clever, eh? Sharks account for some of the largest species of fish in our oceans , with the biggest being the mighty whale shark . These enormous fish can reach a length of 10 metres and weigh in at over 19 tonnes - the equivalent of 15 Ford Fiestas ! Basking sharks and megamouth sharks complete the top 3 biggest species , while the smallest known shark is the dwarf lantern shark , which averages just 6 inches in length .

There are over 1,000 species of sharks that we know of , with new species discovered every year . As our understanding of the seas and oceans widens , and technology continues to improve , it's guaranteed that hundreds of new shark species will be discovered in the coming years . Sadly , however , shark numbers are in decline , which is why organisations like the WWF are campaigning for greater conservation efforts to protect their numbers .

Every species of shark , from the great white to the bonnethead , plays a crucial role in our marine ecosystems - helping to balance a delicate natural order that would otherwise suffer . It's hoped that , as our understanding of sharks deepens and more countries introduce legislation to stop shark hunting, their numbers will return - as has been the case with several species of protected whales . The next few years will prove critical in safeguarding these incredible animals , with a view to not only discover more species , but protect those we already know about .

Sharks are opportunistic feeders , eating everything from small fish and invertebrates ( don't have backbone ) , to seals , penguins , sea birds, and whale carcasses . They detect their prey in several ways , including by sight , sound , vibration and , of course , smell – with a shark able to pick up the smell of blood from over a quarter of a mile away .

You'd be forgiven for thinking that larger shark species eat bigger prey , but this isn't always the case . Sure , a great white could pick off something as formidable as a leopard seal with ease, but bigger species , like basking and whale sharks , are filter feeders , preferring to munch on microscopic plankton . And , despite what films like Jaws may have led you to believe , sharks don't eat humans and would always prefer to stay out of our way . When attacks do happen , it's usually the case that a shark has got confused or feels threatened .

 When attacks do happen , it's usually the case that a shark has got confused or feels threatened

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Some sharks lay eggs and others give birth to live young . This is what's called 'viviparity' or 'ovoviviparity' ; there are more sharks which bear live young than those that lay eggs , and it differs from species to species . Take the whale shark for example , the classic example of ovoviviparity .

Here , this species produces eggs but doesn't lay them . Instead , the young hatch inside the female's body , only to emerge when they've reached a particular size . When we refer to viviparity , this is when a shark releases a capsule containing an egg and a yolk sac , with tendrils designed to anchor it to the seabed . When the baby sharks hatch inside the capsule , they get nutrition from the yolk sac , before eventually being released from the capsule . Some sharks , I like the shortfin mako , give birth in an altogether different way known as oophagy . This is when unfertilised eggs are 'eaten' by embryos inside the shark , before babies are released .

The biggest and most damaging myth about sharks is that they eat humans , which isn't true . When shark attacks happen , it's a matter of wrong place , wrong time - not of predator and prey . So , the next time you take a swim and start thinking about the them tune , put it out of your mind and remember : the likelihood of being attacked by a shark is 1 in 3.75 million .

Remove the fake fear you have to shark . They also should live in this planet not only us . Let's help to protect sharks!

 Let's help to protect sharks!

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