Simplify the following text for a Grade 12 native English-speaking person.
Original: If it finds a small victim Glaucus simply envelops it with its capacious mouth , but if the prey is a larger siphonophore the mollusk nibbles off its fishing tentacles , the ones carrying the most potent nematocysts .
Simplified: If it finds a small victim Glaucus simply envelops it with its large mouth , but if the prey is a larger siphonophore the mollusc nibbles off its fishing tentacles , the ones carrying the most potent nematocysts .