5 Facts On contractile Vacuole In Amoeba

A vacuole is a membrane-enclosed compartment found in the cytoplasm of a cell. Let us understand some facts related to contractile vacuole in amoeba in brief.

Cellular organelles called contractile vacuoles are in charge of osmoregulation and waste elimination. It is located close to the tailing end. It aids in pulling or moving the organism having located at the posterior portion of amoeba at the end.

Contractile vacuole has an oval form, just like other vacuoles. Let us discuss how contractile vacuoles are formed in amoeba, what functions do they perform in amoeba, the structure of contractile vacuoles and many other related questions in this article.

Where are contractile vacuoles found in amoeba?

Contractile vacuole is a spherical regulatory organelle that is found in cells of less advanced creatures, such as protozoa. Let us explore this in brief.

Contractile vacuole is found in the endoplasmic region of amoeba. It acts as a water bubble that control cell’s water content and also aids in excreting waste materials from the cell by diffusion across the cell membrane.

Amoeba may burst even if the contractile vacuole is not present. The pressure of amoeba must be controlled in order to sustain osmotic pressure.

How are contractile vacuoles formed in amoeba?

The excretory organ of amoeba, known as contractile vacuole, is a unique kind of vacuole that aids in controlling how much water should be present in the cell.

Contractile vacuole is mainly formed by contracting and expelling water from the cell. The vacuole periodically expands (water is drawn in) and contracts (ejected). A cycle might take several seconds, depending on the species and the osmolarity of the surrounding environment.

Contractile vacuole functions in amoeba

Contractile vacuoles possess different characteristic features and functions. Let us explore it in detail.

  • Contractile vacuole controls the osmotic balance and assists in the removal of extra water from amoeba’s body.
  • Contractile vacuole helps with waste excretion. Its function is to act as the cell’s pump for removing extra water and waste.
  • The extra water is gathered in the vacuoles when it enters the cytoplasm of the cell. As a result, the vacuole enlarges.
  • Contractile vacuole regulates osmolarity and tonicity by managing the flow of water into and out of a cell.

Contractile vacuole structure in amoeba

Contractile vacuole is associated with a number of components, including membrane folds, tubules, water channels, and tiny vesicles.

Given below is the structure of a contractile vacuole in amoeba:

743px Amoeba PSF.svg
Image credits: Amoeba structure by Kupirijo (CC BY-SA 3.0)

How many contractile vacuoles are present in amoeba?

Contractile vacuole is a globular regulatory organelle in the cells of fewer complex creatures, such as protozoa. Let us check how many contractile vacuoles are present in amoeba.

Amoeba possess one contractile vacuole. Species-specific differences exist in the number of contractile vacuoles present in each cell. Dictyostelium discoideum, Paramecium aurelia, and Chlamydomonas reinhardtii possess two, and enormous amoebas, such as Chaos carolinensis, possess one.

Not all amoebas contain contractile vacuoles. The contractile vacuole is absent in marine amoebae because the solute concentrations inside the cell are equal to the solute concentration of the surrounding water.


From the above article, it can be concluded that the contractile vacuole (CV) complex is an osmoregulatory organelle of free-living amoebas and protozoa enabling cells to survive under hypotonic stress, such that seen in pond water.

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