THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Hydracarina can be collected from almost any aquatic habitat, and may be incredibly abundant and diverse. With very rare exceptions, they begin life as extremely tiny 6-legged larvae that parasitize a terrestrial or aquatic host. After a period of growth on their host, they become free-living nymphs that either return to the water from a terrestrial host or remain in the water and mature into adults. The adults are mostly carnivorous, consuming live or dead macroinvertebrates, but some also feed on detritus.

Hydracarina come in a wide variety of colors (most often red and green, but sometimes yellow, orange, or blue). Their bodies may be hard or soft but are unsegmented and often rounded, with 8 long, thin segmented legs. Their palps may be visible on their head.

Size: xsmall to small
Identifying feature(s): 8 legs; small, usually round, sometimes colorful
Habitat: any fresh waters, including wetlands
Tolerance: moderate