When my friend and I were traveling along the creek, we admired all the frogs when she gasped, "What is that?" I looked to where she was pointing to see a a wire looking thing moving around in the shallow waters. We immediately grabbed it and brought it to the house and put it in a clear container full of pond water to get this video. It was probably around five inches long and very wiry. We let it go and immediately start researching. We found what we had discovered was the Nematomorpha (from the Greek nema, "thread," and morphe, "shape") . Commonly known as Horsehair worm or gordian worm.
One look at the worm, and you think it's a parasite. It is. But it's completely harmless to humans and pets. Instead, it's a parasite of insects which makes them helpful for the insect population. The larvae lives in the insects, and when juveniles, they come out and live in the nearest water source. These worms are commonly found in puddles, streams, ponds, water troughs, and even backyard swimming pools. Every so often, they're found in toilets freaking people into thinking they are a human parasite.
Although the one that I had found was only around five inches long, these millimeter thick parasites reach up to one meter long. The reason for their common name "Horsehair Worm" is the rumor that a horse's hair would fall into a water trough and come to life. Their other name "Gordian Worm" came from the way they would bring themselves into a tight knot (the one that I saw did this when I took it out of the water) that specifically looked like a knot that Gordius, king of Phrygia around 330 B.C. used. As the myth goes, Gordius used this knot to bind a chariot to a pole. He declared that whoever could undo the knot would become ruler of Asia. This knot is commonly known as the "Gordian Knot".
Horsehair worms reproduce in spring, early summer, or autumn. Eggs, often numbering in millions, are laid in long strings similar to gelatin. When laid in the water, the incubation may range between 15 and 80 days, depending on water temperature. The mode of development of the worms after hatching is much to question. Some experts suggest that the larvae encyst on vegetation along the water's edge after hatching. Eventually, some of this vegetation is eaten by the insects in which the larvae will feed upon until juvenile. When it emerges, it usually kills the insect (as the way of helping the insect population).
So these creepy tape-worm looking parasites, are really friends to humans. Who would've guessed that these simple creatures are of such interest?