Physically dangerous
Sharks — supreme predators Sharks are considered the most terrifying of all marine creatures and shark attacks often appear brutal and violent. One species, the White Shark ( Carcharodon carcharias ), is feared above all others. The reality is that although some 40 shark species have been known to attack humans, only three species are to blame for most injuries and fatalities.
the FACTS!
ANY ANIMAL IS AT A DISADVANTAGE when it is out of its element and humans are no exception. Whether wading in the shallows, or swimming in deep water, humans are no match for powerful aquatic predators like sharks.
THE SHAPE of a shark’s teeth is influenced by its diet, ranging from needle-like teeth for gripping fish and flat teeth for crushing molluscs to triangular, serrated teeth for shearing flesh from marine mammals and large fish.
THE WHITE SHARK (below) is the only “warm-blooded” shark. All other sharks are cold-blooded. White Sharks are able to keep their body temperature higher than that of the surrounding water.
RON & VALERIE TAYLOR
WHITE SHARKS have acute eyesight, hearing and sense of smell. They can also detect low-frequency vibrations and minute electric fields and they respond to taste and touch.
The maximum size reached by White Sharks has been the source of many debates and wild speculation. Research indicates that the maximum total length is likely to be about 7 m.
BULL SHARKS are able to move between saltwater and freshwater and have been found thousands of kilometres from the sea in the upper reaches of the Amazon River. Bull Sharks also inhabit Australian rivers and have been recorded up to 90 km inland from the mouth of the Brisbane River in Queensland.
RON & VALERIE TAYLOR
RON & VALERIE TAYLOR
TOP OF THE FOOD CHAIN
Sharks, like this whaler shark ( Carcharhinus sp. ), are sleek, active predators that are constantly on the move. In contrast, bottom-dwelling sharks have a body shape that is appropriate for a more stealthy life on the sea floor.
Text: Queensland Museum. Uncredited photography: Steve Parish
Sharks are an evolutionary success story. They have been around for about 400 million years and “modern” sharks have existed almost unchanged for some 250 million years. The living species range from the harmless 15 m Whale Shark ( Rhincodon typus ) to the 15 cm Dwarf Lantern Shark ( Etmopterus perryi ). Sharks eat almost anything, from plankton and other invertebrate animals to large fish, marine mammals and, if the opportunity arises, humans.