Paramecium is a genus of protists that lives in water. It has organelles called contractile vacuoles that continually eliminate the excess water gained through osmosis. Knowing that Paramecia gain water through osmosis, we can deduce that they normally live in Paramecium is a genus of protists that lives in water. It has organelles called contractile vacuoles that continually eliminate the excess water gained through osmosis. Knowing that Paramecia gain water through osmosis, we can deduce that they normally live in ice and very cold environments. the ocean. very salty environments. freshwater lakes and ponds.

The correct answer is freshwater lakes and ponds.

Explanation:

Paramecium refers to a single-celled species that generally thrives in fresh water like lakes and ponds and relies majorly upon bacteria as the source of their nutrition. They exhibit tiny hair-like projections on the exterior part of their body that helps them in locomotion. Apart from this, as an essential form of adaptation, these species exhibit contractile vacuoles that help them to eradicate excess of water that they gain from their surroundings by the process of osmosis.  

These contractile vacuoles help in maintaining the pressure of water within the body of paramecium by contracting continuously as it helps in discharging excess of water into the surroundings. The presence of contractile vacuole plays an essential role in the life of paramecium as in case if the concentration of salt becomes high in the surroundings in comparison to the concentration present within the body, the organism would die. Thus, it can be concluded that these species thrive in freshwater lakes and ponds.