what do an nautilus  eat
Nautiluses are slow-moving predators that feed mainly on shrimp, small fish and crustaceans, which are captured using their tentacles. They only need to eat once a month because they use very little energy to swim. To swim the nautilus draws water into and out of the shell with its funnel, this produces jet propulsion. Unlike the other Cephalopods, they have an external shell which provides protection and spaces that can be filled with air to adjust their buoyancy.