Species Profile: Rough-skinned Newt

Taricha granulosa, or the ‘Rough-skinned Newt’, is the only newt species in British Columbia. Confined to the coast, the Rough-skinned Newt relies on wetlands for breeding, while foraging is conducted in open seral and mixed forests near permanent water (including wetlands). Their principal targets when foraging are slugs and worms, while also commonly preying on tadpoles and aquatic invertebrates.

Rough-skinned Newt Range

Given their abundance – classified as a Least Concern species – the newts should be easy to identify in the wild assuming you know what to look for. They have a stocky build for a salamander, measuring 11-18 cm in length; their skin is granular, while males are smooth-skinned during breeding season. Their colours are what make them particularly easy to identify: light-brown to olive on top, they boast a contrasting orange to yellow hue on their underside.

Rough-skinned Newts are a particularly interesting amphibian species to study, hence their appearance in our species profile! Taricha granulosa, along with other newts of this genus, produce particularly potent toxins. Tetrodotoxin, the neurotoxin produce by the newt, is the famous toxin found in pufferfish. If ingested, the toxin can induce paralysis and cause death. With that said, if you see a newt in the wild you should be fine as long as you don’t try to eat it; contact with the amphibian may cause skin irritation, but that would be the worst-case scenario and does not happen in most individuals.

With that said, here is a candidate for a Darwin Award: in 1979, a 29-year-old man in Oregon stepped up to a dare and swallowed a 20 cm Rough-skinned Newt. Needless to say, he later died (for more info: http://jama.jamanetwork.com/article.aspx?articleid=359670).

Another interesting note is the “arms race” that has developed in the wild between newts and garter snakes, which serves as a prime example of co-evolution. The common garter snake has a genetic mutation that provides a resistance to the tetrodotoxin, permitting them to be the only known animals that can consume a Rough-skinned Newt and survive.  Their resistance to this toxin has created a selective-pressure that favours newts which produce more potent levels of the toxin. The increases in newt-toxicity then applies a selective-pressure  favouring snakes with mutations that generate an even greater resistance to the neurotoxin. This so-called “arms race” has resulted in the newts producing extreme toxin levels, much higher than what is needed to kill any other predator in the wild.

In summary, don’t be like the Oregon man and take such a bet. You’ll lose every time.

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