The Basking Shark

  At long last I have come to what is arguably Britain's most famous shark. These filter feeding giants are found throughout the Atlantic and the Mediterranean, in addition to much of the Pacific. They feed on plankton and small fish whilst they drift through the seas, open mouthed. They are yet another classic example of a gentle giant: the second biggest fish in the Ocean and yet all they eat are the smallest particles of matter.
  Basking sharks, and other filter feeders, feed by pushing water over their gills and straining plankton from it. They get the water by swimming, which is why filter feeders can not stop moving through water.
  Despite their enthralling size, it is not uncommon for people in New Zealand and California to see basking sharks being hunted by killer whales. Great whites and oceanic whitetips are also known to scavenge a meal from these entrancing sharks' carcasses, but never prey on living specimens due to their reputation for stunning attackers with their heavy tails if defence is required.
  Humans hunt basking sharks for their fins, their liver (for medicinal purposes) and their fat, which is used to make animal feed.

A basking shark filter feeding.

The range of a basking shark.

The Sicklefin Lemon Shark

The sicklefin lemon shark is rather rarer than the managrove-inhabiting lemon shark, commonly found in North America. Unlike its American counterpart, the sicklefin is most commonly found in Australia and East Africa. It inhabits lagoons and estuaries, where it can grow without fear of larger reef sharks like blacktips, silvertips and blacktip reef sharks.

Sicklefin lemon sharks feed on triggerfish, parrotfish and crustaceans, while older individuals have been known to prey on  rays, skates and guitarfish. Remains of sicklefins have been found in the stomachs of silvertip sharks, who are extremely territorial and will fight to the death if another shark enters their area of a reef. Often, they will indulge in a meal of over-curious shark in celebration.

Sicklefins grow up to 3.8 metres long and share the same build as lemon sharks (see above). They also share the same brown and yellow colouration. The main difference is, as the name suggests, the shape of the sicklefin's dorsal fin. It curves back in a sickle-like shape whereas that of the lemon shark does not.

The range of a sicklefin lemon shark.

A sicklefin lemon shark at a reef in the Pacific.

A lemon shark off the shore of Florida. Note the fin shape.

Note the differences between the fin shape of this sicklefin
lemon shark and the lemon shark (above left).

Rays, chimeras and sharks of the past.

Remember that there is still new information waiting for you on the other pages: Sharks of the past and Rays and Chimeras are full to bursting with interesting new species!!

Happy reading.

The Sardine Run

  The sardine run is the annual migration of sardines which attracts sharks, dolphins and even whales from all over the place. Nobody knows exactly what causes this mass-migration-massacre, but a popular theory is that yearly changes in water temperature where the sardines normally live on the coast of Mozambique cause the migration to South Africa's warmer waters.
  The sharks whose presence has been recorded at these frantic all-you-can-eat-buffets consist of dusky sharks, bronze whaler sharks, blacktip sharks (not to be confused with blacktip reef sharks), sand tiger sharks, spinner sharks, Zambezi sharks, great white sharks and occasionally thresher sharks. These are accompanied by common and bottlenose dolphins, Cape fur seals, gannets, turns, cormorants, African penguins and whales of all description. The sardines, when faced with such predators, group into tight shoals to form 'bait balls'.
  The following videos have caught the stunning events in perfect light.
http://www.bbc.co.uk/programmes/p004j1rz
https://www.youtube.com/watch?v=0qtvk9znnnY

The sharks snap up the sardines.

A sailfish darts through the bait ball.

The bottlenose dolphins round up the floundering fish from beneath.

The Common Thresher Shark

  The common thresher shark, also known as the whiptail shark, earns its name from its bizarre and yet successful hunting technique: using its abnormally long tail to stun fish. Its tail is equal in length to the rest of the body. These sharks can grow up to six metres long and are very shy of divers.
  Very few get to witness a thresher shark hunting in the wild, as they are reclusive creatures who spend most of their lives in the deepest parts of the sunlight zone and occasionally they may venture into the twilight zone. They generally feed on mackerel, anchovies and herring, but have been recorded as present for the Sardine Run. They also occasionally eat squid and octopi when they are in shallower waters. They can jump to astounding heights from the water in order to catch fish that make a break for it in the air.
  Unlike the majority of sharks, the common thresher posses certain physiological adaptations that allow them to remain warmer than the surrounding seawater, which is a notable advantage when hunting or being hunted.
  Despite their size, common thresher sharks are not a danger to humankind. Their teeth are small and unlikely to be able to puncture the skin of a human. However, it is important to resign to a safe distance when watching a thresher shark hunting, as its tail has also stunned humans in the past, the majority of whom drowned, with a minority being killed instantly due to a severe injury to the neck or scalp.
  Common thresher sharks are in danger of extinction due to gross overfishing. They are primarily one of the foremost species on the 'finners list of soup ingredients' but are also prized by recreational anglers as they are renowned for putting up a large fight when hooked on a line.

The dark blue shows the recorded range of the common thresher shark.
The light blue shows the suspected range of the common thresher shark.

A common thresher shark warily approaching a diver.

ALL NEW!!

Today, we welcome the all new green fish to SHARK NEWS!! Best start feeding them up!!
Also, you can now enjoy a glorious coral reef background alongside them!!
Happy feeding.

The Blog Poll

Just a reminder, the blog poll is concluded on the 28th of February, so you only have seven days left to vote. Of the seven votes so far, the whale shark has received four (57%) and the tasselled wobbegong three (42%) leaving the oceanic whitetip and shortfin mako on 0 votes each.
The results will be posted on the blog when the poll ends.

Daniel Bailey
www.danielsharkfacts.blogspot.co.uk/

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.