Actinosphaerium is a genus of heliozoans, the members of which look similar to tiny sea urchins due to their spherical shape and radiating, spiny pseudopodia. Actinosphaerium species are multinucleate and may have diameters that reach up to one millimeter in length.

Similar to other heliozoans that are sometimes referred to as “sun animalcules,” Actinosphaerium species are radially symmetrical single-celled organisms. Also, their stiff pseudopodia extend in all directions and are composed of cytoplasm and intertwined helices of microtubules. The extensions are primarily used for capturing prey, which can then be incorporated into the body of the cell through a process known as phagocytosis.

Heliozoans are generally freshwater creatures and can frequently be found in lakes and ponds. Depending on conditions and food supplies, areas may contain large populations, the heliozoans quickly reproducing asexually through binary fission or budding. Suitable food sources for the organisms include algae, protozoans, and other tiny life forms. However, heliozoans generally will try to consume most anything that comes across their paths since they have little locomotive ability.

BACK TO THE DIC IMAGE GALLERY

Questions or comments? Send us an email.

© 1998-2022 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.

This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.

Last modification: Friday, Nov 13, 2015 at 01:19 PM

Access Count Since April 22, 2003: 36654

For more information on microscope manufacturers,
use the buttons below to navigate to their websites: