Category Nuances for null:

• marine,
• benthic,
• resident,
• larger,
• exotic,
• multicellular,
• complex,
• small,
• light,
• extra,
• sedentary,
• unique,
• invertebrate,
• unknown,
• sessile,
• immobile,
• extraordinary,
• higher,
• hard,
• bizarre,

Simple Categories for null:

• inhabitant,
• organism,
• prey,
• pest,
• invertebrate,
• animal,
• surface,
• group,
• worm,
• creature,
• critter,