giraffes, and rhinos. The cattle egret in America as well does the same task of removing the unwanted insects and parasites. Fish Certain fish perform the task of cleaning other fish, by removing ectoparasites, cleaning wounded flesh, and getting rid of dead flesh. Even predatory fish rely on cleansing symbionts, and adopt a placid state while they are cleansed. The fish that do the cleansing are often concentrated around specific sites where the other fish come to be cleansed. These are known as cleansing stations. Bacteria Prominently exhibited between Lactobacillus delbrueckii ssp Bulgaricus and Streptococcus thermophillus, the two symbiotic starter bacteria commonly used in yoghurt starter culture. S. thermophilus produces pyruvic acid, formic acid, folic acid, ornithine, long-chain fatty acids, and which stimulates the growth of L. bulgaricus. The acid lowers the pH of the milk to an optimal level for L. bulgaricus. L. bulgaricus produces peptides, free amino acids, and putrescine through proteolysis, which stimulate the growth of S. thermophilus. See also Symbiosis References Ecology