|You Are Here: Burke Museum : Spider Myths : General : Arachnids|
Myth: "Arachnid" is just a fancy name for spider.
Fact: There are eleven orders of arachnids. These include the scorpions; mites and ticks; harvestmen; pseudoscorpions; whipscorpions; solpugids; and spiders. It's like the relation of beetles with insects: beetles constitute one order of insects, the Coleoptera, but not all insects are beetles. Similarly, not all arachnids are spiders.
|A spider, Missulena occatoria (Australia)||A whipscorpion, Abaliella dicranotarsalis||A scorpion, Charmus indicus (India)||A pseudoscorpion, Chelifer tuberculatus (Algeria)|
|Examples of 7 of the 11 orders of arachnids. Only one is a spider.|
|A whipspider, Paraphrynus mexicanus (Mexico, Arizona)||A solpugid, Eremohax sp. (Mexico, southwest USA)||A harvestman, Phalangium opilio (worldwide)|
Myth: You can always tell a spider because it has eight legs.
Fact: Not exactly. Scorpions, harvestmen, ticks, and in fact all arachnids - not just spiders - have four pairs of legs (see illustrations above). Insects have three pairs. Also, notice that I said "four pairs" instead of "eight." The number of leg pairs (one pair per leg-bearing segment) is more significant than individual legs, which can be lost.
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| Text ©
2003, Burke Museum of Natural History & Culture,
University of Washington, Box 353010, Seattle, WA 98195, USA
Photos © as credited
to Spider Myths author, Rod Crawford
This page last updated 1 September, 2010
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