Gordian Worms are found all over the world. Many animals, such as fish, snails and small crustaceans, get infected. From these eggs, tiny larvae hatch and sink to the bottom, but can only survive for a short time unless they find a host. The adult Gordian Worms attach long egg-strings to waterweeds and other debris in water.

Because these hosts are not found in water, the larvae must reach them by a two-step process. This also led to other common names, such as 'Horsehair Worms' and 'Horsehair Snakes'.Īdult Gordian Worms are free-living in water, but the juveniles are parasitic in land-dwelling insects and spiders. Since they often appear in animal watering troughs and their appearance is not unlike that of horsehair, although they are thicker, it is not difficult to see how this explanation came about. Some communities believe that a 'rain of worms' has occurred, others that horsehairs have 'come to life' after falling into a pond or stream. They are usually found after rains, their sudden appearance leading to stories to explain their presence. Sometimes they get into domestic water supplies, such as toilets or bowls of water. Gordian Worms are found all over the world, in still water such as puddles, ditches, ponds and quiet areas in streams.

The males are often very active in their swimming, while females are more sluggish. There is no distinct head and the male differs from the female in having a forked tail. The diameter is usually not much more than a millimetre. They taper slightly at each end and reach lengths of about 22 cm to 30 cm. Alexander the Great cut the Gordian knot with his sword.Īdult Gordian Worms are shaped like long, thin pieces of cord.

This is after Gordius, King of Phrygia, who tied an intricate knot and declared that whoever untied it should rule Asia. Their habit of writhing and contorting themselves into knots, with one or more worms tangled together, accounts for their common name, 'Gordian' Worm. Gordian worms belong to a small phylum, the Nematomorpha: a name that means 'form of a thread'.

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