The term 'venomous fish' refers to a variety of fish species that have venomous spines or other body parts. One example of a venomous fish is the STINGRAY, which has a sharp, venomous spine on its tail. Stingrays use their venomous spines to defend themselves from predators and to capture prey. The venom from a STINGRAY's spine can cause severe pain and swelling in humans, and can even be fatal in some cases.