overall shape

Description:

Paramecium (aurelia) (par-a-mee-see-um) is a very familiar genus of ciliates. They eat bacteria and have the mouth recessed in a buccal cavity, and the cell is often shaped with a scoop leading to the mouth. There are cilia all over the body with a caudal tuft of longer cilia at the back of the body. Usually with a layer of extrusomes (trichocysts) under the cell surface and a large oval macronucleus. Contractile vacuoles star-shaped. This species is P. aurelia, one of the smaller spindle-shaped (morpho)species. The (morpho) species is best distinguished by the presence of two small micronuclei pressed up against the macronucleus. Phase contrast.