Ciliated Protists as Test Organisms in Toxicity Assessment

Abstract

In recent years, much research has been done to assess the toxicity of various compounds in a series of biotests using several organisms. The appeal of these tests lies in their simplicity and high degree of reproducibility (2). On the other hand, test organisms for assessing environmental risk and impact must possess a lot of desirable features: they must be eukaryotic, their biology and general responses must be well known, the laboratory handling must be relatively easy, and a short generation time is desirable whenever studies of long‐term effects are necessary (3). Ciliated protists fulfill all those requirements. Furthermore, as they have a wide distribution and ecological significance, performing key functions in energy flow and elementary cycling in aquatic foodwebs, they can be ideal early warning indicators of aquatic ecosystem deterioration. Recently, the use of ciliates in toxicological tests has been investigated and their potential in standard bioassays has been demonstrated in aquatic environments and even elsewhere.