Leopard Shark Lunch, Blue Shark Buffet

  Recently, a Cape fur seal was caught on camera as it enjoyed a lunch of leopard shark. Although not aggressive, leopard sharks are still strong and will defend themselves against attackers with ferocity. Yet this cape fur seal managed to make a meal of the reef inhabiting shark.
  This is not the first instance of a cape fur seal making a meal of a shark. In fact, on the 29th of January 2013, one such seal tucked into a blue shark buffet, gulping down five of the worlds second fastest shark in front of several shocked divers.
  Each of the sharks was roughly 1.5 metres long.

Leopard Shark Lunch Link

Blue Shark Buffet Pictures

If you thought that sharks were, in the oceans and seas at least, top of the food chain, think again.

The Bluntnose Sixgill Shark

  One of the few remaining prehistoric sharks, the bluntnose sixgill shark is distinguishable from modern sharks by that which gives it it's name: the fact it has six gill slits. Another differentiating feature of the sixgill is the fact that it has no dorsal fin. The only fin on its back is its second dorsal fin, which is far smaller than the dorsal fin on other sharks and lies directly above the anal fin. These sharks spend the majority of their time roughly 2000 metres beneath the surface and are commonly found in near-coastal waters around Britain, Norway, Denmark, New Zealand, Malaysia, Western North America, parts of China, Japan and Australia as well as throughout the Mediterranean Sea.
  This shark grows up to 5 metres long, although it is generally only female specimens that reach such lengths, with males usually stopping their growth at 3.5 metres. Specimens mostly live for around eighty years.
  The diet of the bluntnose sixgill shark consists primarily of flounder and crustaceans, although they have been known to scavenge a meal from an abandoned whale or sea lion carcass. Although large, the sixgill is not a major threat to divers.
  Fossils of similar sharks to the bluntnose sixgill date back to the Triassic Period, with the shark itself thought to have evolved into today's specimen before the extinction of the dinosaurs.

A bluntnose sixgill shark scavenging
for food at night. Note the lack of a
dorsal fin. 

The Bonnethead Shark

  The bonnethead shark is a subspecies from the hammerhead shark family. It is most commonly found around the Florida Quays, the Gulf of Mexico, New England, Southern California and Ecuador.
  The bonnethead is a popular shark amongst anglers. The reason for this is that they breed quickly and are not likely to become endangered or protected and so to stop their abhorrent sport. Not only this, but they are small and easier to catch than their larger hammerhead compatriots.
  In only one way is the bonnethead shark problematic for anglers. When caught by the tail, as they often are, the bonnethead will use its extreme flexibility to swing round and try to bite the angler who so rudely reeled it in.
  Growing up to 1.50 metres long, the bonnethead is ideal prey for large seabirds, which can sometimes be seen snatching up one of these helpless sharks from the water. However, their diminutive size is beneficial when their turn comes to hunt. With help from the electroreception provided by the denticles on its cephalofoil, which help it sense it's prey, the bonnethead is perfectly equipped to hunt the crustaceans, molluscs, shrimps and small fish which share its habitat. It can pick up the movement of a crab or other small creature and then, even if it is tucked away in a cramp cave which would have been the end of a possible meal for its fellow hammerheads, the bonnethead will remain unperturbed and will use its size to its advantage: sticking its rather smaller head into the cavern and emerging with a meal.
  Although timid and not dangerous to humans, bonnethead sharks have been known to bite anglers when reeled onto a boat. Bonnetheads are often seen in aquariums, where their cephalofoil can represent the most famous feature of all sharks from the hammerhead family to enthralled onlookers, from a safe distance.

A bonnethead shark in an aquarium. Note the shape of the
cephalofoil.