A general image of a shark is enough to strike fear in many people. Now imagine a shark that looks like this:
This is the Sand Tiger Shark, the latest resident in our Shark Seas Habitat. Growing up to 3.2 metres in length and with a mouthful of menacing-looking teeth that protrude in all directions, this is the stuff of nightmares. Or is it? Here are some amazing facts about the Sand Tiger Shark for you to chew on.
Fierce looking but docile
The Sand Tiger Shark has not one but three rows of slender, razor sharp chompers that protrude even with its mouth closed. But looks are deceiving, at least in the case of the Sand Tiger Shark. It is a docile, non-aggressive species, known to attack humans only when bothered first.
Gulps air and hovers
Sand Tiger Shark is the only shark known to come to the water surface to gulp air. But it is not to breathe. This air is stored in their stomachs, which allows them to hover motionlessly in the water (usually just above the ocean floor).
Nocturnal, voracious predators
Generally staying close to the bottom, this nocturnal predator hunt mainly for small fish, and at times crustaceans and squid. They occasionally hunt in groups, and have even been known to attack full fishing nets.
Two ways of breathing
Sharks breathe by buccal pumping or ram ventilation. Buccal pumping means the shark pulls water into its mouth and pumps it over its gills using its cheek muscles. Ram ventilation refers to the shark taking in water as it moves forward, before ramming it through its gills. Ram ventilators need to move constantly in order to breathe, such as the Great White Shark.
Amazingly, the Sand Tiger Shark can breathe either way, switching back and forth as needed. It manually pumps water into its gills when it is resting, then switch to ramming water into its gills when swimming.
This species practices a form of sibling-killing called intrauterine cannibalisation – the pup devours its siblings while still in the womb. The female Sand Tiger Shark’s 9-month pregnancy starts out with up to 50 eggs in each of her two uteri. The first pup to hatch eats the other living embryos and unfertilised eggs in the same uterus. By the time the two surviving pups are big enough to be born, the female will give birth to them – one from each uterus – and swim away.
Sand Tiger Shark pups emerge from their mother measuring in at about 95 to 125 centimeters long – just slightly longer than a baseball bat. This size advantage means fewer predators can pick them off than if they had shared food with their siblings and ended up smaller.