This Centropyxis was captured among freshwater algae sample at Brunswick Community College, Aquaculture Facility located in Brunswick County, North Carolina. Photographed March 4, 2007.
Some of the following images were enlarged using microscope and settings enabling further enlargement from digital camera.
According to Aids to the Recognition of Fresh-Water Algae, Invertebrates and Fishes this creature has the most visible similarities in common with Centropyxis.
Google images produced a variety of similar creatures, so I'll take the chance this creature may be classed among Centropyxis.
I don't know, I don't think it's /Centropyxis/. Just doesn't look like it to me. Spines are in different places. Just my 2 cents.
terri
www.ncseagrant.org

(+/-) Enlarge Centropyxis #1
Magnified at 100x

(+/-) Enlarge Centropyxis #2
Magnified at 100x

(+/-) Enlarge Centropyxis #3
Magnified at 40x

(+/-) Enlarge Centropyxis #4
Magnified at 40x
Additional Links
Centropyxis, Zooplankton, Blog Entry