Sphaerophrya infesting Bursaria, ventral view

Description:

Detail view stalkless parasitic suctorians, Sphaerophrya insolita (Jankowski, 1973) infesting the large colpodid ciliate, Bursaria truncatella (Muller, 1773). The Sphaerophrya cells are ellipsoid and approximately 35 u in diameter. Two suctorians can be seen on the left side (viewer's right) of the vestibular cleft of the host cell and one on the right. There are several posterior to the cleft. Sphaerophrya is thought to have lost its stalk during the transition to a parasitic mode of existence. The cells have capitate tentacles by which they adhere to the pellicle of the host cell. There is a central ellipsoid granular nucleus (the micronuclei have not been characterized). There is a single peripheral contractile vacuole (seen well in a number of these cells). These individuals were found on B. truncatella collected from a temporary rainwater pool containing decaying grass near Boise, Idaho March 2005. DIC.