ABSTRACT
The algal kingdom includes a very wide range of biochemically, physiologically, and morphologically distinct organisms of which only a very few have been used in ecotoxicology. The problem of assessing effects on natural ecosystems is so complex that it is generally simplified to a greater or lesser extent; experiments may be conducted in the laboratory or outdoors in model ecosystems, and a plethora of single species have been used for assaying biological effects. Wild organisms have sometimes been used for each test series, and stocks of these have not been maintained in the laboratory. Any parameter which can be assessed numerically may be used, and these are generally adapted to the test organism and to experimental accessibility. In all the experiments using relatively long-term exposure, advantage may usefully be taken of the opportunity to examine behavioral, morphological, metabolic, and biochemical effects. Exposure of zebra fish to 4-chloroaniline resulted in numerous morphological alterations in the ultrastructure of the liver.
