Holopedium (jelly water flea)
Holopedium spp. · Aquatic life
Under the microscope · Photo: Stephanie Tran / CC BY
Also called Holopedium gibberum, Holopedium glacialis, Jelly clad
How to identify Holopedium (jelly water flea)
- Water flea about 1 to 2 mm inside a clear jelly ball that can be twice its size
- Jelly coat makes samples look slimy or gooey
- Swims slowly on its back
- Visible by eye as small clear blobs
Similar species
Conochilus rotifer colonies are also clear jelly balls but contain many tiny animals.
Profile
| Season | Summer. |
|---|---|
| Depth | Open water |
| How it spreads or reproduces | Females clone themselves through summer; in fall they lay resting eggs loose, not inside a saddle case (ephippium) like Daphnia, and the eggs survive winter on the bottom and can be moved with mud on birds and equipment |
| Habitat | Open water of soft water, low calcium lakes, often in mountains. |
Why it matters in a lake
Its jelly coat protects it from many predators and it can clog water intakes and filters. Common in soft water mountain lakes.
Where it is found
- Idaho: Occasional
- Oregon: Occasional
- Wyoming: Occasional
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Branchiopoda |
| Order | Ctenopoda |
| Family | Holopediidae |
| Scientific name | Holopedium spp. |
Daphnia (water flea)
Bosmina (snout water flea)
Ceriodaphnia (small water flea)
Chydorus (round water flea)
Simocephalus (hanging water flea)
Diaphanosoma (clear water flea)
Moina (lagoon water flea)
Alona (box water flea)
Scapholeberis (surface water flea)
Sida (sticky water flea)Need 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