nuclei

Description:

Paramecium (caudatum) (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. Most species are elongate, although this particular individual has been squashed so that we can see the nuclei. The (morpho)species are distinguished by morphology of the nuclei. This species is P. caudatum, which a single rather globular macronucleus lying alongside (4 o clock) the macronucleus. Phase contrast.