Big worms? Are you serious?

Australia appears to have a fascination with the giant. You just need to look at the tourist traps around the country to know that. Giant banana, pineapple, koala, merino, guitar, lobster... do I need to continue? However, it can also be said that some things naturally come only in large sizes in Aus. Big open spaces. Big numbers of people who disappear (not all at once). Oh, and huge worms. Of course.

There are several species of large worms in Australia. Of the 1000 or so species of native worms, the largest is the Giant Gippsland Earthworm. Its name is straightforward. It's HUGE, is found in Gippsland and is most definitely an earthworm. Its scientific name is Megascolides australis, and its classification is

Most of the worms found in Australia are Megascolecidae, and several other species in Australia can get quite large as well.

M. australis has between 300 and 500 body segments. Its head and the front third is dark purple, while the rest is pink/grey. You can apparently hear them moving underground. An audio comparison was 'like a flushing toilet'.

The entire range of the worm is approximately 50,000-100,000 hectares, or 125,000 to 250,000 acres. This may seem quite a large area, but not when you consider that the worms have a long life, breed very slowly, and have a patchy distribution. The worms hatch out of eggs about a year after being 'laid' (my understanding of annelid reproduction is slight, and it seems the best word). at this point they are about 20cm (8in) long. They reach maturity at about 5 years old, and generally have an average size of 2m long, 3cm thick (80in long, 1in thick). Some reports indicate specimens have grown to 3m in length.

The species is listed as threatened. This is due to a number of factors. Land use practices can have a devastating impact on the worms. Since Gippsland is a primarily rural region, especially in the worm territory, there are certain things that the worms don't like. Grazing was found to be compatible with worms, but superphosphates are thought to be a big no-no. Some people also dig up the worms, either accidentally or intentionally. Accidental excavation can stress the worms, or injure/kill them. Intentionally digging up the worms or destroying their habitat is listed as an offence under Commonwealth law. Damage to the soil banks where the worms live is also bad, but there are many groups attempting to rectify this through site rehabilitation. The worms are also a bit fastidious in their requirements, as they only seem to like certain types of soil (nobody calls it dirt, it's soil. It's more complicated. Dirt is silly. Soil is serious). These are apparently a blue-grey or dark red clay soil. They only seem to like stream banks, gullies, soaks and some hills that face either south or west. Fussy, aren't they?

The worm was first scientifically described in 1878 by Professor Frederick McCoy, Director of the National Museum of Victoria, after being thought to be a snake. There hasn't been all that much research on the critter. Most of the early stuff was done by making inductive generalizations based on European worm research. The most in-depth research was the Ph.D. thesis by Beverly Van Praagh in 1994. Her thesis was quite interesting to read, however, I got confused very quickly. In November 2005, she took part in a group relocating some worms from an area sanctioned for roadworks. They removed 600 worms, but unfortunately had a mortality rate of 20%.

And there is a giant worm monument. It's a museum all about the worms. Apparently Bill Bryson mentioned it. It's called the "giant earthworm museum", at a place called Wildlife Wonderland, in or near a town called Bass, about 10 minutes from Phillip Island. Thanks heppigirl for that.

Sources

  • www.deh.gov.au
  • www.dpi.vic.gov.au
  • www.des.vic.gov.au

"The biology and conservation of Megascolides Australis McCoy 1878" - submitted by Beverley Diane Van Praagh, 1994, School of Zoology, La Trobe University.

Log in or registerto write something here or to contact authors.