Usually, two dorsal fins sprout at the tip of the tail, which lacks any dangerous spine. The mouth and gills are on the undersurface, eyes on nostrils on top. Modified scales often create a thorny dorsal surface. They wait for small animals like sand lance, squid and crabs to pass within pouncing distance or actively grub through sand and gravel for clams and worms. Like most cartilaginous fish, skates are fertilized internally with the males highly modified anal fins, or claspers.
Females lay mermaids purses, or egg cases, throughout the year in relatively shallow water.
Long spurs at each end of the purse act as an anchor to surrounding rocks or algae to keep embryoes from being swept away. The wings of a skate can be processed into sea scallops using a cylindrical cookie cutter. Recently, a number of species of skate have gained in popularity as table fish. Their relatively low birth and growth rate makes them vulnerable to sustained, high catches.