| Hydrachnidia | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Arachnida |
| Subclass: | Acari |
| Order: | Trombidiformes |
| Suborder: | Prostigmata |
| (unranked): | Parasitengona |
| (unranked): | Hydrachnidia |
| Superfamilies | |
| Synonyms | |
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Hydrachnidia, also known as "water mites", Hydracarina or Hydrachnellae, are a group of mites covering more than 40 families and 5 000 species (Smith & Cook 1991) found in freshwater and marine habitats. As water mites of Africa, Asia, and South America have not been well-studied, the numbers are likely to be far greater. Other taxa of parasitengone mites include species with semi-aquatic habits, but only the Hydracarina are properly subaquatic. They exist in a variety of freshwater bodies, such as treeholes, hot springs, deep lakes and waterfalls, and some have adapted to marine environments.