Sand tiger shark has a flattened head with a pointed snout and a long mouth. The teeth of these sharks are long, pointed and curved, and visible even when the mouth is closed. Sand tiger sharks are known by different names depending on where they live. In Australia, they are called gray nurse sharks. In South Africa, they are known as ragged-tooth sharks. In the United States and United Kingdom, they are usually called sand tiger sharks.
Sand tiger sharks have a grayish brown upper body with colored spots, and lighter underneath. They grow up to 10 feet (3 meters) long. They are slow-moving sharks that live in shallow tropical and temperate coastal waters in oceans worldwide. They eat fish, squid, and often prey upon smaller sharks. They sometimes hunt cooperatively in groups of 20 to 80 individuals to prey on schools of fish. Sand tiger sharks may live longer than 16 years in the wild.
Sand tiger sharks migrate toward the poles during the summer, and then back towards the equator during the fall and winter. A sand tiger shark controls its buoyancy (power to float) in the water by gulping air at the surface and storing it in its stomach. By regulating the amount of air in its stomach, a sand tiger shark can control its depth in the water column. It can even hover motionless in the water column.
Female sand tiger sharks are ovoviviparous. That is, the female protects the eggs, which hatch within her body. The young are born alive. Most females give birth to a pair of young, called pups, every two years. The developing sharks in her body will eat other eggs produced by the female. Biologists call this oophagy. Developing sand tiger shark pups may also practice embryophagy. Here, the largest embryo in each of two uterine (womb) tubes consumes all smaller embryos.
Sand tiger sharks are an endangered species protected by law in Australia and in the United States. However, they are fished for food, taken for their fins for the shark fin trade, or caught as bycatch in other regions. Bycatch includes fish and other marine animals that are inadvertently captured along with target fish species. The toothy jaws of sand tiger sharks are often sold as souvenirs. They are also a popular species for aquarium collections.
