Zooillogix

Via a circuitous route, prompted by a friend of Zooillogix, Tweet Gainsborough-waring, I found myself looking at the picture below.

This otherworldly Australian earthworm, Terriswalkeris terraereginae, not only looks likes delicious candy, but the mucin it releases is luminescent, and it grows up to 2 meters long. I knew Zooillogix readers would want to know more about this fascinating critter but could find almost no information online. Luckily, Dr. Geoff Dyne, Assistant Director, Queensland Section, Australian Government Natural Research Management Team (and more importantly, earthwormologist), generously provided me with the following information about Australia's formidable Oligochaetes.

Courtesy of Dr. Dyne:

Australia is home to some of the largest earthworms in the world. This little-known zoological morsel is easily overlooked when one considers the more charismatic elements of the fauna that usually rate a mention - such as koalas and kangaroos.

Size is relative, of course; when we think of large earthworms (or terrestrial Oligochaetes), we are perhaps considering species growing in excess of 30cm or one foot or so in length. In Australia, all of these species belong to the Family Megascolecidae.

Some of these earthworms are associated with upland areas of rainforest growing on volcanic soils, such as Terriswalkeris terraereginae, found in the mountains behind Cairns in Far North Queensland. This large species is all the more striking for being a deep Prussian blue. Rarely seen, it (together with a number of the other deep-burrowing species) is occasionally exposed by road-building machinery or when heavy rain saturates the soil and forces individuals out of their burrows.

Another unusual large earthworm is Digaster keasti, known from the great sandy region in southeast Queensland, which includes Fraser Island, the world's largest sand island. It has become adapted to what would usually be regarded as a somewhat precarious, if not impossible, habitat for an earthworm - podsolised sand. These extensive sand soils are subject to desiccation in their upper layers but contain just enough humic material and deep moisture to support the existence of these remarkable animals. Digaster keasti is also bioluminescent - an interesting phenomenon exhibited by other earthworms species and which is worthy of a separate article.

The Grand-daddy of these overachieving oligochaetes is the Giant Gippsland earthworm, Megascolides australis, found in clayey soils under the banks of streams and in south or west facing hills in the Gippsland region of eastern Victoria (south-eastern Australia).

She named this big one "Bitey"

It commonly reaches a length of about 2 to 3 metres (6.5 to 10 feet), and is about 2cm (0.8 inches) in diameter when extended. The biggest specimen recorded by the National Museum of Victoria is...

(more below the fold)

...nearly 4 metres (13 feet) long. The small town of Korumburra, which is near the epicentre of the occurrence of M. australis, celebrates its unique faunal asset with an annual worm festival called Karmai (the local Aboriginal name for the species). It is reputed that when in close proximity to these animals, one can detect faint gurgling noises as they move through their burrows.

Megascolides australis also has the dubious honour of being the only earthworm to be listed under Australian national threatened species legislation, largely because of its very restricted distribution.

A few final thoughts and questions from Zooillogix:

Does anyone know if the luminescence is chemical or bacterial? (note - this was Kevin Z's first question after he got done crying over my breaking the story on this badboy).

Does anyone have a picture of Digaster keasti?

Is nuking Australia from orbit the only way to be sure?

Would love to have other earthwormologists weigh-in on these new media darlings.

Special thanks to Dr. Geoff Dyne for providing us with this fascinating information.