Biology/Natural History: A predatory snail. Prey includes Littorina, barnacles. Egg capsules are 4-9 mm long. Some only develop to the gastrula stage, while some continue development and eat these "nurse eggs". There are 17 to 46 embryos per capsule. Hatch as juveniles. Crepidula adunca are sometimes found on this snail, though Crepidula prefers the black turban snail.