But species matters.
Here in New Zealand, we have about 200 species of earthworms, most of which are native. The native and non-native worms are sharply segregated by habitat—natives in native habitats, non-natives in agricultural and urban habitats. So all the worms we see in our gardens are non-native species.
When you’re used to the small to medium sized non-native worms, finding a native worm is exciting. They’re generally larger than the non-native worms—sometimes much larger. Some can grow to nearly a metre and a half (59 in) in length.
We were lucky enough to find this native worm on Mount Oxford over the weekend. I can’t positively identify the species, but it’s likely to be Octochaetus multiporus. This was a young specimen—not yet reproductive age (as evidenced by its lack of a clitellum)—but already about 20 cm (8 in) long and as thick as my pinky finger. This particular species grows to about 30 cm (12 in) long.
O. multiporus is a particularly interesting worm because it is bioluminescent and spits a bioluminescent defence compound when disturbed. On the bright sunny day we found this one, there was no hope of seeing any bioluminescence. Still, it was a great find on our walk.