Most people give little thought to earthworms. Even gardeners, who appreciate their presence, don’t spend much time considering which species of worm are present.

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.