S: (n) shark (any of numerous elongate mostly marine carnivorous fishes with heterocercal caudal fins and tough skin covered with small toothlike scales)
S: (n) nurse shark, Ginglymostoma cirratum (small bottom-dwelling shark of warm shallow waters on both coasts of North America and South America and from southeast Asia to Australia)
S: (n) hammerhead, hammerhead shark (medium-sized live-bearing shark with eyes at either end of a flattened hammer-shaped head; worldwide in warm waters; can be dangerous)