Modifiers matching billfish:

• large,
• oceanic,
• threatened,
• larger,
• exotic,

Simple categories matching threatened:

• marsupial,
• bird,
• animal,
• fish,
• waterfowl,
• predator,
• reptile,
• creature,
• billfish,
• group,
• waterbird,
• ecosystem,
• species,
• mammal,
• fauna,
• carnivore,