Category Nuances matching gastropod:

• terrestrial,
• small,
• marine,
• intertidal,
• common,
• smaller,
• large,
• herbivorous,

Members for simple category gastropod:

• periwinkle,
• slug,
• lightning_whelk,
• limpet,
• snail,
• abalone,
• queen_conch,
• whelk,
• mussel,
• oyster,