Toxin-producing bacteria can make this newt deadly
Some newts living in the western United States are poisonous, perhaps thanks to bacteria living on their skin. Rough-skinned newts use tetrodotoxin — a paralytic neurotoxin also found in pufferfish and the blue-ringed octopus — as a defense against predators. But rather than making the toxin on their own, the amphibians (Taricha granulosa) may rely on microbes to produce it for them, researchers report April 7 in eLife. It is the first time that researchers have found tetrodotoxin-producing bacteria on a land animal. Tetrodotoxin, or TTX, prevents nerve cells from sending signals that tell muscles to move (SN: 6/26/14). When ingested in low doses, the toxin can cause tingling or numbness. High amounts can trigger paralysis and death. Some newts harbor enough TTX to kill several people. Marine animals including pufferfish get TTX from bacteria living in their tissues or by eating toxic prey. It was unclear how rough-skinned newts acquire the lethal chemical. Previous work in 2004 had hinted that the newts didn’t have the toxin-producing bacteria on...