The Bass River Valley in South Gippsland, located in the state of Victoria, southeastern Australia, is home to the largest earthworm species in the world, which can grow up to over 2 meters long.
The Gippsland giant earthworm (Megascolides australis) is one of the most elusive yet fascinating creatures on the planet, capable of surviving in an environment completely altered by its inhabitants and rarely seen above ground.
These giant earthworms can only be found in a wide area, with habitats covered by dense forests, but have now been entirely converted into agricultural land.
Besides its enormous size, the ability to thrive in an environment where native vegetation has been completely removed is another intriguing characteristic of the Gippsland giant earthworm.
The largest earthworm in the world.
This elusive earthworm was discovered in the 1800s when workers surveying a railway line accidentally unearthed a specimen. Believing it to be some type of snake, they brought it to a professor at the University of Melbourne, who confirmed that it was indeed an oversized earthworm.
Since then, earthworms measuring over one meter have been discovered, as well as many others exceeding 2 meters in length.
Although the Guinness World Record for the largest earthworm belongs to a species called Microchaetus rappi in South Africa, measuring 6.7 m (21 ft), Megascolides australis is still regarded as the largest earthworm species in the world.
These earthworms have very soft skin, which is why they live in damp, fixed burrow systems. Due to their size and the moist soil surrounding their burrows, the rapid underground movement of the Gippsland giant earthworms creates strange sounds reminiscent of water draining from a bathtub.
These peculiar sounds are loud enough to be heard above ground and are known to “terrify the uninitiated.”
Using their muscular heads to burrow through the ground while feeding on fungi, bacteria, algae, and microorganisms, Gippsland giant earthworms can reach depths of over 1 meter.
They are among the most elusive creatures known to humans, as they are rarely seen above ground. In fact, the only time they emerge is during heavy rain when their burrows flood.
The largest earthworm in the world with impressive length.
While giant earthworms are adaptable and thrive in their native habitat, the significant changes in their environment over the past two centuries are astonishing, and human impact has placed this species on the endangered list.
Toxins used in agriculture and their physical vulnerability due to their size have not helped the situation, nor have their mating habits.
No one really knows how Gippsland giant earthworms mate, as emerging above ground seems unlikely due to the threat from predators, and their underground burrows are barely wide enough for two earthworms to pass through at the same time.
Some scientists hypothesize that the worms may stretch their bodies, thus becoming thin enough for two of them to fit snugly in the burrow together, but no one really knows for sure how that occurs.
The Gippsland giant earthworm will only lay one egg per year, from which a single individual will emerge after about 12 months.
With a relatively large size at the time of hatching, the baby earthworm is already quite big, but it grows very slowly throughout its life. Some scientists suggest that it can live up to 10 years or even longer.
