Giant Gippsland earthworm
|Giant Gippsland earthworm|
These giant earthworms average 1 metre (3.3 ft) long and 2 centimetres (0.79 in) in diameter and can reach 3 metres (9.8 ft) in length, however as their body is able to expand and contract making them appear much larger. On average they weigh about 200 grams (0.44 lb).  They have a dark purple head and a blue-grey body, and about 300 to 400 body segments. 
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 4 centimetres (1.6 in)to 7 centimetres (2.8 in) in length which are laid in their burrows. When these worms hatch in 12 months they are around 20 centimetres (7.9 in) long at birth.
Unlike most earthworms which deposit castings on the surface, they spend almost all their time in burrows about 52 centimetres (20 in) in depth and deposit their castings there, and can generally only be flushed out by heavy rain.  Their movements are very sluggish and can be found through the underground burrows can cause an audible gurgling or sucking sound which allows them to be detected.
Located near the town of Bass is the Giant Earthworm Museum. This building allows tourists to 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 are featured.
As with many of Australia’s native species, European colonisation has resulted in the decline of the Giant Gippsland earthworm and they are now a protected species. Some farmers in the area have stopped raising cattle and have begun planting crops. When the farmers till the ground many of the worms are severed, and some scientists believe that worms are killed as a result of the tilling. The species has survived this massive change because it can burrow deep into the soil. However, due to the effects of farming it is still considered a threatened species. Other contributing factors are their low reproductive rate and slow maturation. No successful breeding has yet been achieved in captivity.
- Giant Palouse earthworm - A vulnerable North American species.
- Oregon giant earthworm - A relative of the Palouse earthworm. Specimens have been recorded at 1.3 m (4 feet) long.
- Lake Pedder earthworm - Listed as the first "extinct" worm species from its original unique Tasmanian habitat.
- Lumbricus badensis - Giant (Badish) earthworm.
- Microchaetus rappi - Giant South African earthworm.
- "Giant Gippsland Earthworm". Museum Victoria. Retrieved 14 December 2013.
- Diversity of Soil Fauna and Ecosystem Function, Biology International. Retrieved on October 23, 2008.
- AU Environment http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=64420
|url=missing title (help). Retrieved 14 December 2013.
- Action Statement: Giant Gippsland Earthworm. Retrieved on July 23, 2012.
- Victoria Resources Online: Giant Gippsland Earthworm. Retrieved on July 23, 2012.
- World Conservation Monitoring Centre (1996). Megascolides australis. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Listed as Vulnerable (VU D2 v2.3)