Actinophrys (Protozoan) Videos   Get Adobe Flash player
Originally named "Sun Animalcules," these predatory organisms
belong to the protozoan class Heliozoa (superclass Actinopoda).
They are found most often in freshwater, floating in the open
water amongst reeds and filamentous algae. Actinophrys is
notable for having more than one nucleus. In general, heliozoans
are spherical and are frequently enveloped by a shell, or test,
made of silica or organic material. Organisms secrete the shell
in the form of scales or pieces in a gelatinous covering. The
shells exhibit a wide variety of shapes, which can be used in
species identification. Heliozoans reproduce asexually by binary
fission or by budding, but several genera have flagellated forms
that may possibly be sex gametes.  A unique feature of the
superclass Actinopoda is the presence of specialized
pseudopodia, called axopodia, that extend outward in a rayed
pattern. These appendages are used for locomotion and for
capturing food: protozoans, algae, and othe