The Cookiecutter Shark

  The cookiecutter shark is a small shark which inhabits deep waters. It can grow up to fifty centimetres in length and spends the day at depths of up to 3,570 metres below the surface. They rise to the surface at night, where they hunt their prey. It is rather hard to imagine what prey a minuscule shark such as this could hope to catch at the surface of the open ocean. Most Sunlight zone creatures are larger animals than those of the Twilight and Trench zones. The few small fish species there are do not often stray into the open ocean. However, the cookiecutter shark has developed a hunting technique so sophisticated, it is hard to believe it is true.
  The cookiecutter shark has an unusually rounded jaw for a shark. The reason for this is its hunting technique. Using its bioluminescent body, the cookiecutter shark attracts other sea creatures to it. These creatures are, more often than not, dolphins, sailfish and whales. As the animal passes by, the diminutive shark uses its jaw to latch on. it then swims in a circle until it tears away a cookie-sized piece of its victims tissue. Hence the name, cookiecutter.
  Due to the fact they only come into humanly accessible waters at night, cookiecutters are rarely encountered by people. However, using cameras, they have been monitored by biologists, which is how we first learnt of their feeding method. Cookiecutter attacks on people are extremely uncommon, both for the reason above and the fact that humans have less blubber than dolphins and other creatures they prey on.
 

A cookiecutter shark examining a diver's camera.

The range of the cookiecutter shark.

The unusually rounded jaw of a cookiecutter shark.

A cookiecutter shark bite on a yellowfin tuna.

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.

The Longfin Mako Shark

Almost as rare as the megamouth, the longfin mako shark is found in the deep sea, near to six hundred metres below the surface, in the Atlantic, Pacific and Indian oceans and the Mediterranean Sea. Sadly, they do not tend to stray as far as Britain. Despite being very rarely seen and one of the most little known about sharks still in existence, they are nonetheless truly fascinating creatur
  There have been no recorded attacks on humans by longfins, as they hardly ever mix with the creatures of the Sunlight Zone. Their diet consists of small fish, diamond squid and deep sea jellyfish, this mix of food leaves them smaller than other sharks, but a sustainable meal in the Twilight Zone and Dark Zone where they live is very hard to come by. However, this lack of food may just give them the edge over the sharks of the Sunlight Zone when it comes to hunting. Their senses are sharpened by hunger and when they have to find their food, they rarely fail.
  So we have covered the prey of the longfin, but now we turn to the predators. With the absence of killer whales and omnivorous, cannibalistic sharks such as tigers, great whites and bulls, the longfin mako shark has only two predators: deep sea fishermen and the majestic and mysterious giant squid, terroriser of the deep sea and ruler of the dark water. They kill with silence and without mercy. As with most of the creatures from the Dark Zone, they are not fussy and eats whatever it finds. Longfins are no exception. Their powerful petorcal fins (which give them their name) and sharp teeth are no match for the giant squid's tentacles, suckers, unimaginable strength and sheer size. As was mentioned above, deep sea creatures are not fussy. This makes them easy prey for fishermen who only have to drop their lines baited with rich, Sunlight Zone fish such as tuna and chum for many unsuspecting, malnourished fish (and evidently sharks) to come knocking.