What is the most venomous fish?

The most venomous fish is the stonefish, especially the reef stonefish. Its venom is delivered through sharp dorsal spines and can cause extreme pain, paralysis, tissue damage and death without prompt treatment.

Stonefish are masters of camouflage. Their rough, irregular bodies can resemble rocks or coral, allowing them to remain motionless on the seafloor while waiting for prey. People are most often injured when they accidentally step on one in shallow coastal water. The dorsal spines can pierce footwear, and pressure activates venom glands at their bases.

The reef stonefish has 13 venomous dorsal spines, giving it an exceptionally effective defensive system. It is found mainly in the Red Sea and Indo-Pacific, including rocky reefs, sandy bottoms and tidal areas. Stonefish feed on small fish and crustaceans, often engulfing prey in a remarkably fast strike.

Lionfish and scorpionfish are also venomous, but the stonefish is generally recognized as the most venomous known fish. It is venomous rather than poisonous: its toxin is injected through a spine, rather than being dangerous merely to touch or eat.