If you think amphibians look a bit prehistoric, you’re right: they’re the oldest land animals on Earth and can trace their lineage back more than 360 million years! The life cycle of PEI’s modern frogs, toads, newts, and salamanders mirrors amphibians’ ancient evolutionary path, starting out in water before changing form and moving to land. But one is unique, with a life cycle like no other. Meet the Red-spotted Newt (Notophthalmus viridescens viridescens).
Like frogs, toads, and salamanders, Red-spotted Newts lay eggs in water and hatch into aquatic larvae a few weeks later. Over the summer, the larva grows legs and a tail and trades gills for lungs. By fall, it’s become a bright-red Eft (shown here) and is fully terrestrial. My photo doesn’t do the colour justice, and Efts stand out dramatically against the forest floor. Their bright colouring serves as a warning to predators that they are toxic – Efts carry tetrodotoxin in their skin (the same nerve poison found in Pufferfish). It’s safe to handle Efts, just don’t try to lick one!
For most amphibians, this terrestrial stage would be the adult, but Red-spotted Newts are not most amphibians. Efts will live several years on land before growing into their final adult form, which is so unlike the Eft that they were once thought to be an entirely different species! Adult Red-spotted Newts are olive green and yellow with flattened (almost fin-like) tails useful for swimming. This stage can live for more than a decade and is mostly aquatic, though they can travel over land if needed.
This Newt’s life cycle is remarkably adaptable. Under certain conditions, larvae can mature directly to adults (for example, if pond conditions are exceptionally good or the land around it isn’t Eft-friendly) and adults can sometimes return to the Eft stage (if the pond dries up, for example). Newts also have the ability to regenerate lost limbs, tails, organs, eyes, and even spinal cords.
Despite these fantastic adaptations, Red-spotted Newts are vulnerable to habitat loss and environmental contamination. Their presence is considered an indicator of ecosystem health, and I was happy to spot this one last week in Eastern Kings.
Red-spotted Newts are a truly unique part of PEI untamed!