Venom is the poison certain fishes and other creatures use to stun or kill their victims. Among fishes, the most deadly venom is found in members of the scorpionfish and rockfish families. Ichthyologists (scientists who study fishes) consider them as a group because these fishes all have a bony plate going across the cheek from the eye to the gill cover. (The gills, located on the sides of the fish, are like lungs; they allow the fish to breathe by taking in oxygen from the water.)

These members of the scorpionfish family have spines coming from the dorsal (top), ventral (side) and anal (bottom) fins. Along the sides of each spine are grooves containing venom glands. People poisoned by turkeyfish venom have nearly died. The turkeyfish will attack an object, jabbing at it with its dorsal spines. These fishes live in the tropical areas of the Indian and Pacific Oceans.

The Hawaiian lionfish, which lives only in Hawaiian waters, is the most venomous of Hawaiian reef fishes. You can easily recognize it by the long spines on its fins. Its body is reddish brown with white vertical stripes, and it may reach 10 inches in length. The lionfish seems to be fearless, maybe because he knows how dangerous his venom is. While scorpionfish sit quietly and wait for prey, the lionfish will sometimes join with other lionfish to herd small fishes into a crack. The lionfish spread their fins to keep the small fishes from escaping then attack and eat the smaller fishes.