Actinosphaerium are freshwater protists that are "radially symmetrical" meaning they have body parts that are arranged around a central axis or point. They are part of a group of protists called heliozoans. The prefix "helio" means relating to the sun.  When you look at the Actinosphaerium, it has the appearance of the sun.  This is due to its long slim arms called "axopodia" or "axopods" that are actually cytoplasm that is stiff.  The axopods are actually pseudopods that help the organism in a few ways.  One is movement, and the other is to capture prey that sticks to the axopod as it passes. As a result, this organism will eat a variety of things.