Скачать или смотреть Opisthostyla annulata

Opisthostyla annulata Stokes, 1886
Ciliophora, Peritrichia
         Found at Patterson Park Lake, Baltimore, MD, USA, the body length of Opisthostyla annulata found measured between ~20 μm and ~30 μm.
        Easy to identify by its hollow stalk which acts like a spring and obvious annulations. Opisthostyla, though solitary, is related to the Epistylididae. The stalk is curved at the attachment and when the zooid is startled, it is thrown backward and recovers in the blink of the eye. The zooid contracts into an oval shape when this happens.
         The shape of the zooid is an elongated inverted bell with a peristomial lip and elevated disc. One contractile vacuole is located under the peristomial lip. Macronucleus is "C"-shaped and located in the vicinity of the infundibulum which penetrates the cell about one-third the body length.