Sunday, November 15, 2015

Spiders, Scorpions, and What Not, Part 3: Harvestmen

The harvestmen are arachnids that belong to the order of Opiliones, formerly the Phalangida. There were over 6,500 species of harvestmen discovered by December 2011, although the total number of extant species might as well be over 10,000. Harvestmen, sometimes called daddy longlegs, have three defining characteristics that help us distinguish them from other arachnids. These characteristics are that they have a single pair of eyes, their body segments are fused into a single segment, and their legs are immensely long.

Harvestman

In the total truth, harvestmen are not venomous, and are not a threat to humans in any way. However, there is one characteristic of theirs that might freak some people out. When a harvestman is attacked by a predator or is startled, it will simply lose one of it's long legs. But, to ensure the actual harvestman stays alive, it uses another method. After it's leg falls off, it just continues to twitch. This happens thanks to the "pacemakers" found at the base of their legs, which send electrical signals that tell the muscles in the leg to continue to contract and relax in a rhythmic pattern. Although the legs of most species only twitch for about a minute, other species' legs have been clocked to twitch for about an hour before stopping.

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