It should be understood that there's a significant differnce between poisonous[i and [i]venomous] ... At least here in the U.S., all saamanders are poisonous... meaning the emit toxic substances thorugh their skins that can be deadly, but noe are venemous... meaning thier bite does not inject toxins into the victim.
Haing said that, there's at least one species of salaander with a unique way of defending itself described here:
"Certain salamander species (genera Pleurodeles and Tylototriton) have tubercles running down the sides of their bodies. If the animals are grasped or attacked, they can push their sharp ribs through these as a defence mechanism. As the ribs pass through the skin, the salamanders begin to secrete toxins from special glands on its body. The toxin coated ribs create a highly effective stinging mechanism, injecting through the thin skin and then into the predator or attacker."