Megascolecidae

Aporodrilus ponga

Called The Megascolecidae (from Greek mega = large and scolex = worm), in German (and English ) usually somewhat misleading "giant earthworms " ( "giant earth worms" ), are a family of segmented worms ( Annelida ). Within the annelids they belong to the Wenigborstern. You do not belong, despite their German and English name and their partially similar ecological function by kinship to the earthworms ( Lumbricidae ).

Occurrence, and size adjustments

The Megascolecidae usually live in the soil, but partly also on trees or shrubs; individual species are also found in fresh water and sea. Those species that live in dry soils, show specific biological and physiological adaptations (eg, so-called Enteronephridien, ie excretory organs, which open into the intestinal tract, rather than as in the other annelids directly to the outside ), leading to liquid savings contributes.

In Australia, the worms (about 3 meters in extreme cases allegedly ) and up more than finger- thick ( the extreme case, about 3 inches ), reaching up to 2 meters long, a weight of up to about 450 grams. They are there also a tourist attraction, which is even dedicated an impressive array Museum ( Giant Earthworm Museum, Bass, 70 miles south-east of Melbourne). However, some species are also quite small.

Proliferation and threat

The Megascolecidae occur naturally in Australia, New Zealand, Africa, South and Southeast Asia (eg Japan ) and America face; the original area of ​​distribution seems to have been the Southern Hemisphere ( Gondwanaland ). Today they are part, particularly in Australia, under serious threat, presumably through displacement by the new arrivals European earthworms is a major factor.

System

Both the relationship of Megascolecidae to the other Wenigborstern ( Oligochaeta ) and the kinship relationships within the family are being discussed still controversial. Morphological and molecular genetic findings contradict each other as a result of Homoplasien in many places.

Currently be distinguished by morphological differentiation around 34 genera. For more information on the biology of individual species see under

• Megascolides australis, the Giant Gippsland earthworm in the Australian state of Victoria;
• Driloleirus americanus, the giant Palouse earthworm in the U.S. state of Washington.