Protozoan contractile vacuole

Abstract

Scope and Method of Study: In this report, the writer has attempted to compile data concerning the functional and structural aspects of the protozoan contractile vacuole. The method of study was various textbooks and periodicals available on contractile vacuoles.

Findings and Conclusions: Although contractile vacuoles occur in various phyla of living organisms, almost all information on these organelles is derived from studies on protozoa. The contractile vacuole does not seem to be an organelle of uniform structure, even among protozoa. There are great differences as to its shape, size, number and presence or absence of a permanent canal. In spite of these variations all contractile vacuoles have some common features: they form by the fusion of smaller contributory vacuoles; and they have a remarkable fast contraction at systole. The contraction which results always in the emptying of the content, lasts in almost all contractile vacuoles 2 to 3 seconds.

In most cases the contractile vacuoles serve as osmoregulatory devices which remove excess water from the cell and is thought by some to be an excretory organelle.