Paramecium bursaria

Paramecium bursaria is a single-celled organism belonging to the genus Paramecium, which are known as ciliates. These microscopic protozoans are typically oval-shaped and covered in cilia, which they use for movement and to sweep food particles into their mouths.1

A unique characteristic of Paramecium bursaria is its ability to form a symbiotic relationship with the green alga Chlorella. This symbiosis allows P. bursaria to gain nutrients through photosynthesis from the algae, in addition to its usual method of ingesting bacteria and other small organisms.2

Like other protozoans, Paramecium primarily reproduces asexually through binary fission. However, they also engage in sexual reproduction through a process called conjugation, where two individuals temporarily unite to exchange genetic material, which is crucial for their long-term survival and genetic variation.134