A sexual process called conjugation periodically takes place in which two paramecia fuse together and exchange micronuclei. The pristine DNA in the micronucleus re-establishes the genetic integrity of the macronucleus. To stimulate conjugation, starve a natural population of Paramecium . Paramecium bursaria , the green paramecium, hosts hundreds of green algae belonging to the genus Chlorella . Look for Vorticella in pond water samples, on the walls of aquariums, in water dishes of dogs, and just about all other aquatic habitats.
Mitochondria are often difficult to see in living cells.
Examine Vorticella 's clear stalk under high magnification to see them in abundance. The colonial-stalked ciliate with the specialized reproductive individual is Systylis , a beautiful study in adaptation to life in temporary pools. Stalked ciliated are very common. Stentor is one of the largest cells. In fission, the feeding apparatus develops first, then gradually a new cell is defined and pulls free.