The world's most venomous fish is a close relative to the scorpionfishes, known as the stonefish. Through its dorsal fin spines, the stonefish can inject a venom that is capable of killing an adult person in less than an hour

Diver and Stonefish, Medas Islands, Spain
Scorpionfish, Bonaire (Scorpaena plumieri)
Tassled Scorpion
False Stonefish