fish. Because they are strict aerobes, they are also indicators of relatively stable
streams or lakes. Crustaceans have been used to reduce the level of algae in bodied or
Figure 3-1. Rotifera.
Figure 3-2. Microscopic crustaceans.
d. Potability. Nuclear, biological, and chemical potable water is that which is
free of disease-producing organisms, agents, and toxic chemicals. The sanitary
microbiologist is concerned with the presence of pathogenic organisms in water.
Unfortunately, specific pathogens are not readily detected or identified by normal