Modifiers matching benthos:

• marine,
• mobile,
• small,
• sessile,
• motile,
• moving,
• large,

Simple categories matching motile:

• organism,
• invertebrate,
• creature,
• event,
• fauna,
• cell,
• process,
• prey,
• plankton,
• activity,
• metazoan,
• group,
• benthos,
• phenomenon,
• animal,
• crustacean,
• nekton,
• eukaryote,
• predator,
• behavior,
• system,
• algae,