Polyarthra (feather rotifer)
Polyarthra spp. · Aquatic life
Under the microscope · Photo: Environmental Protection Agency / Public domain (Wikimedia Commons)
Also called Polyarthra dolichoptera, Jumping rotifer, Polyarthra vulgaris
How to identify Polyarthra (feather rotifer)
- Microscopic, about 0.1 to 0.2 mm, boxy soft body
- Twelve long flat blades or paddles in four bunches along the sides
- Jumps suddenly by flicking the blades to escape predators
- Often common in lab counts year round
Similar species
Hexarthra also jumps but uses six muscular arms with bristles; Synchaeta is cone shaped without blades.
Profile
| Season | Present all year, including under ice; often peaks in summer. |
|---|---|
| Starts | Any water temperature |
| Depth | Open water |
| How it spreads or reproduces | Females clone themselves through the season; tough resting eggs survive drying and travel on birds, wind and equipment |
| Habitat | Open water of ponds, lakes and reservoirs of all types. |
Why it matters in a lake
Feeds on small algae, especially cryptomonads, and is food for young fish and predatory zooplankton.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Rotifera |
| Class | Eurotatoria |
| Order | Ploima |
| Family | Synchaetidae |
| Scientific name | Polyarthra spp. |
Keratella (spined rotifer)
Brachionus (rotifer)
Asplanchna (sac rotifer)
Kellicottia (long spine rotifer)
Filinia (bristle rotifer)
Synchaeta (cold water rotifer)
Trichocerca (rat tail rotifer)
Conochilus (colonial rotifer)
Lecane (flat rotifer)
Euchlanis (glass rotifer)Need a hand?
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