Amoebae and relatives
Sun animalcules
Heliozoans (Actinosphaerium, Actinophrys)
Round cells with many straight, stiff rays like a child's drawing of the sun. They drift and wait for prey to touch a ray.
What to look for
- Spherical body with fine radiating axopods, each with a stiff inner core.
- Frothy, bubbly outer cytoplasm.
- Moves very slowly, by rolling or drifting.
Size in the field
Actinophrys is small; Actinosphaerium can be up to about a millimetre across.
Where to find it
Among water plants in clean ponds.
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