Two case studies exploit unique historical databases to follow population dynamics of yellow perch and European perch ( ) and to demonstrate how fisheries and habitat management can drastically influence the fate of fish populations. Three other chapters are dedicated to the general reproductive physiology, parasitology, and behavior of species. The third species, the Balkhash perch ( ), is a rare and threatened species of the Balkans, and a chapter is dedicated to its biology. The book ends with a review of the use of species around the world as sentinels of ecological integrity and biomonitors in ecotoxicological studies.