scallop: edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions
bivalve: marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
heterokontophyta: algae having chlorophyll a and usually c, and flagella of unequal lengths; terminology supersedes Chrysophyta in some classifications