Acari

Overview

Acari are a taxon of the Arachnida class and are the most abundant as well as the most diverse of the arachnids that include animals such as mites and ticks. The existence of these creatures has been dated as far back as 400 million years ago to the early Devonian Period, making them the oldest terrestrial animals. Due to their immense diversity, they vary heavily in terms of size,shape, and structure. The species of Acari are relatively small in size being as small as the human follicle mite at around 0.1 mm and as large as ticks or the Red Velvet mite which can be as large as 10 mm. [1] As of 1999, over 50,000 species of Acari have been documented and it is estimated that around 1 million more have yet to be discovered. [2]

Habitat and Distribution

Because of their vast abundance and diversity, acari are distributed to essentially all locations of the world. Their presence has been recorded as high up as the slopes of Mt. Everest, as deep as 3 miles below the surface of the ocean, and even on the continent of Antarctica. These minuscule animals can be found in almost any particular habitat from the hot springs of Yellowstone to the seemingly uninhabitable Saharan desert. Despite most of the species being defined as free-living, some species of Acari are parasites of other animals.

References

1. Walter, David Evans; Krantz, Gerald; Lindquist, Evert (December 13, 1996) "Acari. The Mites. Tree of Life Web Project.

2. Walter, D.E.; Proctor, H.C. (1999). Mites: Ecology, Evolution, and Behaviour. University of NSW Press, Sydney and CABI, Wallingford. ISBN 978-0-86840-529-2