Fish Venom Unveiled: Toxins Evolved Many Times, Study Shows

More than 2,000 species of fish are venomous, and a new analysis of these animals shows that the most common way they deliver their venom is through spines on their backs. The research, which analyzed the evolution of venom and its delivery mechanisms among freshwater and saltwater fish, also found that venom glands arose 18 separate times among fish. "For the first time ever, we looked at the evolution of venom across all fishes," lead author William Leo Smith, assistant curator at the Universi