URL: https://www.blogto.com/city/2025/04/hammerhead-worms-ontario/
Native to Asia and deemed invasive in North America, hammerhead worms get their nickname from their distinctive T-shaped heads and dark red stripe running down the length of their squirming, slimy bodies.
The species of B. adventitium that has been confirmed as present in Ontario packs a potent punch for any animals that mistake them for a slimy snack. Tetrodotoxin, a neurotoxin found in some of the world's most deadly animals, like the pufferfish and blue-ringed octopus, poses serious danger to pets and even humans.
Scientists aren't aligned on the evolutionary function of this toxin for the worms, but there is no doubt about just how harmful tetrodotoxin is. Its oral median lethal dose (LD50) of 334 micrograms per kilogram in mice is orders of magnitude more toxic than even potassium cyanide at 8,500 micrograms per kilogram.