The Great Hammerhead Shark

  The great hammerhead shark is one of the world's largest sharks; and one of the most dangerous. Thirty three shark attacks have been attributed to it. These ferocious hunters can grow up to six metres long and they feed off stingrays, large fish and smaller sharks. They are opportunistic hunters and often feed on grey reef sharks after they have been exhausted through mating. In addition, they have cannibalistic tendencies.
  Great Hammerheads are found throughout the world in Temperate and Tropical waters. They are, however, badly endangered as their fins are very valuable ingredients for shark fin soup.
  The difference between a great hammerhead and the more common scalloped hammerhead, is the shape of the hammer (or cephalofoil, to use the scientific term). That of the great hammerhead is wider and lacks the dips which earn the scalloped hammerhead its name. The cephalofoil is used to detect electronic signals in the water, which are produced by its favourite prey: stingrays.

A close up of a scalloped hammerhead shark's cephalofoil.

A great hammerhead near Australia. Note the difference
of its cephalofoil to that of the scalloped hammerhead's.

The Dwarf Lanternshark

  The dwarf lantern shark is the smallest known species of shark. It grows to roughly twelve centimetres long - about the length of a ballpoint pen. These reclusive micro-sharks at depths of four hundred and forty metres, meaning that they are not often encountered by humans.
  Wether this shark is endangered or of least concern, no one knows. Their range is small - nearly as small as they are! - and fisheries in the areas where they live have repoted netting them as bycatch. They have been classed as data deficient by SHARKDEFENSE.
  These deep-sea-nipprs rise to the Sunlight Zone by night to hunt in schools of several hundred specimens, catching solitary fish and sometimes small sharks, like dogfish.

The minute range of the dwarf lantern shark.

A dwarf lantern shark spotted in the Twilight zone by
a very lucky diver.

The frilled Shark

  Perhaps the queerest looking of all the sharks, the frilled shark is very rarely encountered by humans and is one of the prehistoric sharks.
  Prehistoric sharks posses six or seven gill slits, rather than the five which can be found on all normal sharks. The three known specimens with more than the usual number of gill slits are the sharpnose sevengill shark, the bluntnose sixgill shark and the frilled shark. None of these sharks is often seen by divers. One of the most recent frilled shark encounters resulted in several angry outbursts from marine welfare activists when the people who had seen it hauled it onto their boat and put it in a freshwater tank. The shark tragically died within twenty minutes.
  The diet of a frilled shark consists of squid, large fish and smaller sharks. Their large,  gawping mouth enables them to swallow prey up to half its length. However, frilled shark feeding has never been witnessed as it takes place in the ocean's unexplored depths. Their diet is only known through the stomach contents of two or three individual specimens.
  Frilled sharks grow up to two metres in length, but is not a danger to humans. Frilled sharks are not overly threatened by extinction seeing as their fins are not valued by illegal finners.

A frilled shark drifting peacefully along a reef.

This picture depicts the range of the frilled shark.

Blog Views

Several people have asked me which country has viewed the blog most. Well, here is your answer:

United States

891

United Kingdom

859

Latvia

263

France

160

Germany

137

Russia

83

Australia

67

Canada

50

Thailand

25

Indonesia

23

If your country isn't on the top ten, view more!!
Daniel Bailey
www.danielsharkfacts.blogspot.com

The Blog Poll

  From now on, there will be a monthly poll for you to vote in on the blog. We have done a trial run for it, and so far, four people have voted on "Which of these sharks would you most like to swim with?"
  To vote, just click on the box next to the shark you chose and the click vote. Once you have done that, reload the page and your vote will be registered.

Daniel Bailey
www.danielsharkfacts.blogspot.com

Dangers to Sharks Part II

This is the second of the dangers to sharks posts.
  We have previously viewed the dangers to great white sharks. Now, we turn to the opposite end of the scale with the small, but no less remarkable, swell shark.
  As explained in the previous post, swell sharks have a very good defence mechanism. However, they still have very persistent foes who pose great threats to it throughout its life.
  Unlike the great white shark, the swell shark is not often threatened by humans. Hunters see it as an unremarkable prize. Although I would beg to differ, as I find it a wonderful creature, their lack of interest in hunting it is appreciated.
  Primarily, swell shark eggs are often swept onto the shore by the tides. Although not a technical predator, the waves can be a fatal foe for the unborn swell sharks. Once they have hatched, swell sharks face an immediate threat from lobsters and crabs, with which they share the reefs of the Indian and Pacific oceans and the Mediterranean Sea. These clawed crustaceans will trap a newly-hatched swell shark pup and devour it. Thankfully, shark pups immediately know how to swim and hunt when they leave their eggs, so this does not happen often.
  As adolescents and adults, swell sharks are no longer likely to fall prey to lobsters and crabs, however, their new predator is even more deadly than the last: black tip reef sharks.
  Black tip reef sharks are not generally viewed as the best hunters, but come sundown, they congregate  into schools of up to fifty or sixty and stalk the reefs for unfortunate prey. They might not be big but neither are the swell sharks, which are dwarfed by the night-stalking hunters; one bite from those 'giants' would end a swell shark's life.

Black tip reef sharks gathering at a reef to hunt come nightfall.

The Swell Shark

  The swell shark is a thoroughly interesting species of shark. It dwells in crevices in tropical reefs by day and merges to hunt come nightfall. They are small sharks that are generally shy around divers. As they grow only to an estimated one hundred centimetres long, they have reason to hide away for fear of discovery by larger reef sharks which may have an intent to kill it.
  The diet of a swell shark consists of small fish and crustaceans. Amazingly, these opportunistic creatures have been known to enter lobster pots to find an easy meal. In turn, these sharks are the prey of many other marine specimens. However, swell sharks do have a stunning defensive technique: as it says in their name, a swell shark will jam itself between two rocks and inhale water to make itself impossible to extract from its position. When the predator has left the vicinity, the shark exhales and swims away. Simple, yet remarkable.
  Swell sharks are found on reefs in the East Pacific, along the West coast of North and South America and throughout the tropical waters of Hawaii. Although they are not generally dangerous to humans, they have been known to act threateningly and even aggressively if a diver comes to near or appears to be a predator. They have also occasionally been known to bite a diver's limb as a warning, but with no fatalities.

A swell shark off the shore of Western North America.

A swell shark jammed between two rocks in defence.