Chemical Information

Abstract

Water can dissolve a wide variety of compounds and both animate and inanimate objects continually release chemicals into the surrounding water. There is, therefore, a chemical “landscape,” which reflects the physicochemical and biological aspects of the environment, including the ion and gas content of the water, for example salinity and oxygen concentration, as well as the many secretions and excretions of plants and animals. This wealth of information, coupled with the presence of acutely sensitive chemoreceptors in fishes (Kleerekoper 1969; Hara 1982), is a potential basis for effective orientation and timing.