Earthworms growing up to 3 meters long that make gurgling sounds underground. Endemic to a tiny region, they're threatened by farming and have never been bred in captivity.
Arthur Bartholomew (1833—1903), Public domain, via Wikimedia Commons
A subterranean giant
Beneath the clay soils of Gippsland, Victoria, lives one of the largest earthworms in the world, Megascolides australis. While they average around 1 meter in length and weigh about 200 grams, individuals can reach up to 3 meters. These invertebrates have a dark purple head and a pinkish-grey body, which consists of 300 to 400 segments.
The worm's existence was first scientifically recorded in the 1870s when railway workers surveying land near Brandy Creek unearthed a specimen they mistook for a snake. Professor McCoy at the University of Melbourne identified it as a giant earthworm, giving it its scientific name. Unlike common earthworms that deposit castings on the surface, the Gippsland Giant spends nearly its entire life in a system of burrows, which can extend 1.5 meters deep. They deposit their castings within these tunnels. The presence of these elusive creatures is often revealed not by sight, but by a peculiar gurgling sound. This noise is created when the worms move rapidly through their wet burrows, a sound sometimes audible to a person walking on the surface.
A fragile existence
The Giant Gippsland Earthworm lives in a small, 40,000-hectare area of West and South Gippsland. Its habitat is specific, requiring the moist, blue-grey clay soils found along stream banks and on wet, south-facing slopes. These worms require a high degree of soil moisture to respire through their skin. this area was originally covered in forests, but has since been largely converted to farmland for dairying and other agriculture.
This species is listed as Vulnerable under both Commonwealth and Victorian conservation laws. The populations are fragmented and face threats from agriculture, such as soil cultivation and chemical runoff, which can harm the worms directly and alter their habitat. Changes to the local hydrology from road construction and drainage can also lower the water table, drying out their burrows. The worm's biology makes it susceptible to these pressures. It has a slow maturation rate, taking up to 5 years to reach adulthood, and a low reproductive rate. Each breeding season, which occurs in the warmer months, a single egg is laid within a tough, amber-colored capsule that is 4 to 8 centimeters long. The young worm hatches after about 12 months, already measuring around 20 centimeters. All attempts to breed the Giant Gippsland Earthworm in captivity have failed, making the preservation of its natural habitat essential for survival.
💡Fun Facts
When discovered by railway workers in the 1870s, they were initially mistaken for a new species of snake.
A baby earthworm is already 20 centimeters long when it hatches from its sausage-shaped egg cocoon.
The worm's movement through its wet, underground burrows creates a loud gurgling sound that can be heard on the surface.
It has a very slow life cycle, taking 5 years to mature and producing only one egg per year.
The Giant Gippsland Earthworm lives in the wild and cannot be viewed in a captive setting. The Giant Earthworm Museum at Wildlife Wonderland Park closed permanently in 2012.
Admission
Not applicable
Accessibility
The earthworm's habitat is located across private and public land in rural Gippsland, primarily in clay soils near creek beds, which can be wet and uneven. Direct observation is extremely rare as they live deep underground and are a protected species.
