The sand tiger shark, also known as the gray nurse shark, is a slow-moving coastal predator distinguished by its flattened, conical snout and spiked, protruding teeth similar to the tiger shark. It has small eyes and light brown skin that resembles sand, helping the shark blend into its surroundings when looked at from above.1
The sand tiger shark lives worldwide near the seafloor in surf zones, shallow bays and coral and rocky reefs. They are a large species, growing to a maximum length of 10.5 feet (3.2 m) and weight of 350 pounds (159 kg).2 The sand tiger shark is the only shark that is known to maintain neutral buoyancy by gulping air at the water’s surface and holding it in its stomach. This allows the sand tiger shark to hover motionless in the water.1 2
Like many sharks, the sand tiger shark is a solitary species but can be found in small schools for feeding, mating and birth. Sand tiger sharks mate via internal fertilization and give birth to about two pups every two years (one in each uterus). They have one of the lowest reproductive rates among sharks due to intrauterine cannibalism,3 in which eggs and developing embryos are eaten by the largest embryo until only one remains.4
Sand tiger sharks are not cannibalistic after birth but are known to feed on small sharks of other species. They are voracious predators and feed on a variety of bony fish, including hake, herring, snappers, wrasses, remoras, eels and much more. Sand tiger sharks also feed on rays, crabs, lobsters and squid. They sometimes feed cooperatively with other sand tiger sharks by herding and surrounding schools of fish.1 Juvenile sand tiger sharks are vulnerable to predation by larger sharks, including great white, tiger, shortfin mako and bull sharks. Adult sand tigers have no natural predators.
Like other shark species, sand tiger sharks can detect the electrical current of prey using electroreceptors in their snouts. This is particularly advantageous for sharks like the sand tiger which feed on bottom-dwelling prey that hide in the sand.5
Sand tiger sharks are targeted in some commercial fisheries for their fins, for their meat in Japanese markets, for their oil in Australian markets and for the aquarium trade worldwide. Sand tiger sharks are primarily caught by line fishing. They are also vulnerable to being caught commercially and as bycatch in bottom trawls and gillnets. Because of their coastal habitat, sand tiger sharks are overfished and experienced a 75 percent decline from 1980 to 1990 as a result. Overfishing, paired with the sand tiger shark’s extremely low reproductive rate, has led to the species being listed as vulnerable to extinction. Without ending the shark fin trade and stopping overfishing, the sand tiger shark could become extinct.4
1. Sand tiger sharks are denser than water and maintain buoyancy by swallowing air and holding it in their stomachs.
2. Sand tiger sharks may look menacing with their pointed teeth but are considered sluggish and not a threat to humans.
3. Sand tiger sharks grow to a maximum length of 10.5 feet (3.2 m).1
4. Sand tiger sharks can be found from the surface of the water to 656 feet (200 m) deep.4
5. Sand tiger sharks can detect electrical signals from prey about 8 to 12 inches (20 to 30 cm) away.6
Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.