This book provides an up-to-date review of the biology of myxozoans, which represent a divergent clade of endoparasitic cnidarians. Myxozoans are of fundamental interest in understanding how early diverging metazoans have adopted parasitic lifestyles, and are also of considerable economic and ecological concern as endoparasites of fish. Synthesizing recent research, the chapters explore issues such as myxozoan origins; evolutionary trends and diversification; development and life cycles; interactions with hosts; immunology; disease ecology; the impacts of climate change on disease; risk assessment; emerging diseases; and disease mitigation. This comprehensive work will appeal to a wide readership, from invertebrate zoologists, evolutionary biologists and developmental biologists to ecologists and parasitologists. It will also be of great practical interest to fisheries and conservation biologists. The identification of key areas for future research will appeal to scientists at all levels.

"Adult Chinook salmon, Oncorhynchus tshawytscha, must pass eight hydroelectric dams and reservoirs and migrate more than 1000 river kilometers to reach spawning grounds in the South Fork Salmon River in central Idaho. Behavior during migration, energy depletion, and ultimately reproductive success may be affected by river conditions (e.g. temperature and flow) and dam operations (e.g. spill) within the migration corridor. In this study we examined the energy use of migrating adult Chinook salmon through the Columbia and Snake Rivers in order to investigate the relationships between initial fish condition, migration experience, and river conditions, and eventual migration and spawning success. As part of this research, we also tested non-lethal methods to estimate adult salmon energy condition."--Preface (page ii).

Migration patterns of adult spring chinook salmon above Willamette Falls differed depending on when the fish passed the Falls, with considerable among-fish variability. Early-run fish often terminated their migration for extended periods of time, in association with increased flows and decreased temperatures. Mid-run fish tended to migrate steadily upstream at a rate of 30-40 km/day. Late-run fish frequently ceased migrating or fell back downstream after migrating 10-200 km up the Willamette River or its tributaries; this appeared to be associated with warming water during summer and resulted in considerable mortality. Up to 40% of the adult salmon entering the Willamette River System above Willamette Falls (i.e. counted at the ladder) may die before reaching upriver spawning areas. Up to 10% of the fish passing up over Willamette Falls may fall-back below the Falls; some migrate to the Columbia River or lower Willamette River tributaries. If rearing conditions at hatcheries affect timing of adult returns because of different juvenile development rates and improper timing of smolt releases, then differential mortality in the freshwater segment of the adult migrations may confound interpretation of studies evaluating rearing practices.