Quote:
It is important to note that a thin membranous lining called a cuticle covers lionfish. Since lionfish are sedentary fish, the cuticle is used to protect the lionfish from settling organisms. In fact, lionfish will occasionally shed their cuticle to remove any unwanted hitchhikers. A shed cuticle looks like a large mass of whitish stringy mucus, and this shedding occurs when a lionfish just start flashing around the aquarium, trailing white stringy mucus behind it. Cuticle shedding is also a sign of improper health in lionfish, as stressed lionfish or lionfish kept in poor water quality will increase shedding behavior.