How did the sarcastic fringehead get its name?

The name ‘fringehead’ refers to the floppy fronds of tissue that fall over the fish’s eyes, while the term ‘sarcastic’ is thought either to describe the animal’s sardonic closed-mouth expression, or to derive from the Greek word sarkázein, which means ‘to tear flesh’. Either way, the only thing that’s cutting about this fish is its set of teeth.