Most gastropods move by waves of muscular contraction along a broad creeping foot, sliding on mucus. Strombid conchs abandoned that. The operculum, the horny door that in other snails seals the shell, is reduced to a narrow, sickle-shaped, sharply pointed blade.
The animal digs that blade into the substrate, contracts the foot to lift and thrust the shell forward, then repeats. The result is a series of discrete leaps, sometimes called stromboid locomotion, that lift the shell clear of the sediment and produce a much faster escape than gliding allows. The same operculum doubles as a defensive spike against predators such as spiny lobsters and octopuses.
The conch also has surprisingly good eyes for a snail, borne on long stalks with a lens and a well-developed retina, and it retracts and hops when a shadow passes. What is regularly overstated is the shell's growth story: the flared lip forms only at maturity, so a large but unflared conch is a juvenile. Fisheries that measure only shell length therefore harvest animals that have never bred, which is why lip thickness is now used in management.