Native and Exotic Earthworms in Tasmania

Native/Exotic

Tasmania has around 230 species of native earthworms (similar to New Zealand with around 200) including one in the North east that is related to the giant Gippsland earthworm (a specimen is held by the Queen Victoria Museum in Launceston). In Tasmania, as soon as farmers began to clear the trees and started to cultivate the soil, the native earthworms retreated to the surrounding bushland.

I have never seen a native species of earthworm on agricultural land.

To differentiate between native and exotic earthworms, count the segments between the head and the clitellum (the ‘saddle’) – native worms have less than 20 segments while the exotic worms have more than 20 (note: Juvenile worms don’t have a clitellum).

Exotic earthworms were mainly introduced accidentally by the early European settlers, primarily in potted plants brought from Europe.

However, I suggest that staff of the Van Diemen’s Land Company intentionally brought the large field worm (the black-headed worm, Aporrectodea longa) from England early in their companies’ history as the species is most common around Woolnorth, Stanley and Ridgley – land once owned by the company.