The giant Gippsland earthworm (Megascolides australis), is one of Australia's 1,000 native earthworm species.
These giant earthworms average 1m (03feet) long and 2cm (01inches) in diameter and can reach 3m (10feet) in length; however, their body is able to expand and contract making them appear much larger. On average they weigh about 200g.[1] [2] They have a dark purple head and a blue-grey body, and about 300 to 400 body segments.[3]
They live in the subsoil of blue, grey or red clay soils along stream banks and some south- or west-facing hills of their remaining habitat which is in Gippsland in Victoria, Australia. These worms live in deep burrow systems and require water in their environment to respire. They have relatively long life spans for invertebrates and can take 5 years to reach maturity. They breed in the warmer months and produce egg capsules that are 4cm (02inches) to 7cm (03inches) in length which are laid in their burrows. When these worms hatch in 12 months they are around 20cm (10inches) long at birth.
Unlike most earthworms which deposit castings on the surface, they spend almost all their time in burrows about 52cm (20inches) in depth and deposit their castings there, and can generally only be flushed out by heavy rain. They eat organic matter as well as bacteria and fungi, which may have allowed them to better adapt to the change from a forest to pasture living area. [4] They are usually very sluggish, but when they move rapidly through their burrows, it can cause an audible gurgling or sucking sound which allows them to be detected.[5] [6]
Gippsland earthworm colonies are small and isolated, and the species' low reproductive rates and slow maturation make those small populations vulnerable.[7] Their natural habitats are grasslands, and while they can survive beneath pastures, cultivation, heavy cattle grazing and effluent run-off are adversarial to the species. The Gippsland earthworm requires moist loamy soil to thrive; dense tree planting negatively affects soil humidity, which in turn negatively affects the species' habitat. No successful breeding has yet been achieved in captivity.
Until it closed in 2012 amid animal welfare concerns,[8] Wildlife Wonderland Park near Bass, Victoria, was home to the Giant Earthworm Museum.[9] Inside the worm-shaped museum, visitors could crawl through a magnified replica of a worm burrow and a simulated worm's stomach. Displays and educational material on the giant Gippsland earthworm and other natural history of Gippsland were also featured.
Interest in the giant Gippsland earthworm has been exploited by the local tourist industry with an annual Karmai Festival in Korumburra.[10] In the Boonwurrung language it is said to have been called karmai.