Why This Fish Actually Needs a Hole in the Head

Why This Fish Actually Needs a Hole in the Head: A cavity in the middle of the rockhead poacher’s skull might be used like a maraca to produce sound, new research suggests. By Alexa Robles-Gil Ten years ago, Kory Evans, an evolutionary biologist, was staring at an unusual fish in a lab. The fish, a rockhead poacher, was tiny and chunky, he said,