The sandbar shark, also known as the brown shark, is the most common shark species along the mid-Atlantic coast and is commonly found over muddy or sandy bottoms in shallow coastal waters such as bays, estuaries, harbors, or the mouths of rivers. As one of the largest coastal sharks in the world, its most distinguishing characteristic is a taller-than-average first dorsal fin. Sandbar sharks swim alone or gather in sex-segregated schools that vary in size and undergo seasonal migrations influenced by temperature and ocean currents. Unlike most sharks, the female gives birth to six to thirteen live pups in shallow water nursing grounds every 2 to 3 years.