Bearded scorpionfish (Rob, BBM Explorer / CC BY)
Scorpionfish (Scorpaenidae) commonly have stout bodies with large heads adorned with ridges and spines. Their dorsal fin rays are coated with venomous mucus. Typically scorpionfish lie motionless and well camouflaged on the sea bottom, waiting for potential prey. They range from 5 centimeters (2 inches, minor scorpionfish) to 36 centimeters (14.2 inches, tassled scorpionfish) in length. Scorpionfish are considered dangerous to humans. The symptoms of a sting vary from a uncomfortable prickle to intense pain, swelling, diarrhea, nausea, and headaches.