Water mites
Hydrachnidia · Aquatic life
Whole animal · Photo: Donald Hobern / CC BY
Also called Hydracarina, Hydrachnidia, Red water mites
How to identify Water mites
- Tiny round bodies about 1/50 to 1/8 inch, like a moving bead
- Eight legs (larvae have six), with no separate head or waist
- Often bright red or orange; others green, blue, yellow or brown
- Swim steadily or crawl over plants; never hop
- Red larvae ride as tiny parasites on insects such as damselflies and mosquitoes
Similar species
Seed shrimp (ostracods) look like tiny clams and have a shell. Copepods and water fleas swim in jerky hops. Spiders have a waist between two body parts.
Profile
| Season | Present all year; most noticeable in spring and summer. |
|---|---|
| Starts | Present all year; most active in warm months |
| Depth | Plant beds and bottom |
| How it spreads or reproduces | Larvae hitch rides on flying insects |
| Habitat | Plant beds and bottom debris of almost every pond, lake and stream; also in springs. |
Why it matters in a lake
Common and harmless to people and fish; most are predators of tiny insects and crustaceans. The bright red ones are often mistaken for spiders or ticks.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Arachnida |
| Order | Trombidiformes |
| Scientific name | Hydrachnidia |
Water springtails
Fishing spiders
Daphnia (water flea)
Midge larvae (bloodworms)
Keratella (spined rotifer)
Mosquito larvaeNeed a hand?
Found it in your lake?
Send us a photo and we will identify it and tell you what it means for your lake.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596