Fishhook water flea
Cercopagis pengoi · Aquatic life
Under the microscope · Photo: Dmitry Kulakov / CC BY
Also called Fishhook waterflea, Cercopagis pengoi
State listing
- Idaho: Prohibited invasive species
How to identify Fishhook water flea
- Small water flea body with a very long tail spine, about 0.25 to 0.5 inch overall
- Tail spine ends in a hooked loop
- Single large dark eye
- Clumps on fishing lines look like gelatin with tiny black dots
Similar species
Spiny water flea is larger with a straight, barbed tail spine and no hooked end.
Profile
| Season | Summer and fall; hatches from resting eggs. |
|---|---|
| Depth | Open water |
| How it spreads or reproduces | Females clone themselves; resting eggs survive in mud and bilge water and on fishing gear |
| Habitat | Large lakes and reservoirs; not known from Idaho, Oregon or Wyoming. Watch for it on boats and gear coming from the Great Lakes region. |
Why it matters in a lake
An invasive predator of native zooplankton that competes with young fish for food and fouls fishing lines. Clean, drain and dry boats and gear.
Where it is found
- Idaho: Not yet found
- Oregon: Not recorded
- Wyoming: Not recorded
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Branchiopoda |
| Order | Onychopoda |
| Family | Cercopagididae |
| Scientific name | Cercopagis pengoi |
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