A summer resident of Delaware Bay, where it bears its young, the sand tiger matures at about 7 feet. While in the oviduct, the embryos are cannibalistic and eat the other eggs and each other until only one survives. This allows the pups to grow quite large before birth. Young of up to 40 inches have been reported. Curiously, this shark reportedly swallows air, holding the air in its stomach to achieve neutral buoyancy, and has been observed resting motionlessly off the bottom.
Small groups have been know to herd and prey on schools of fish.
There are at least 370 species of shark in the world, ranging from 6 inches to more than 40 feet long. Eighty percent of the world's shark species are under 5 feet when fully grown. Many sharks are becoming endangered because people like to eat them. To learn more about other sharks of the U.S. Mid-Atlantic region, check out the Shark bulletin in our Sea Grant publications catalog.