[3][4][5] Although the bacteria are parasites by definition, they also exhibit mutual relationship with the protist by providing survival benefits.

[7][8][9] Paramecium biaurelia was described by Tracy Morton Sonneborn in 1975 while analysing the different cryptic species of P.

[1] Paramecium biaurelia is a unicellular protist with elongated body, which measures about 133 μm in length.

They are energy parasites as they depend on the host's ATP for their energetic functions, but they increase the growth rate of the protists in return.

[4] Paramecium biaurelia is present in Europe, Asia, Australia, New Zealand, Tasmania, and North and South America.