Marine snail whose shell has a broadly triangular outer whorl and a wide lip, often jutting toward the uppermost point. True conchs (family Strombidae) feed on fine plant matter in warm waters. The queen conch (Strombus gigas), found from Florida to Brazil, has an ornamental shell; the pink opening into the first whorl of the shell may be 12 in. (30 cm) long. The clam-eating fulgur conchs (family Melongenidae) include the channeled conch (Busycon canaliculatum) and the lightning conch (B. contrarium), both about 7 in. (18 cm) long and common on the U.S. Atlantic coast. See alsowhelk.