Freshwater fish ecology /
Herry Kenyes.
- vi, 214 pages ; 24 cm.
Includes bibliographical references and index
Fish ecosystem -- Fish parasite -- Freshwater fish diseases and disorders -- Freshwater fish culture -- Pathogens in marine and freshwater environments.
"Freshwater fisheries are the most heavily exploited aquatic resources, producing about a quarter of the world's food fish from less than 0.01 per cent of the world's water resources. Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05% These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations. Freshwater fish differ physiologically from salt water fish in several respects. Their gills must be able to diffuse dissolved gasses while keeping the salts in the body fluids inside. Their scales reduce water diffusion through the skin: freshwater fish that have lost too many scales will die. They also have well developed kidneys to reclaim salts from body fluids before excretion. Fishes live in a world that is unfamiliar to us. Although we may make or even more advanced brief visits to this other world using a snorkel, scuba diving equipment, we can never become a part of it. Yet, an understanding of fish ecology requires an awareness of the relationships between fishes and their environment. The fish farmers and fish& fisheries students too can benefit from this book." -- Back cover