Freshwater to seawater transitions in migratory fishes

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The transition from freshwater to seawater is integral to the life history of many fishes. Diverse migratory fishes express anadromous, catadromous, and amphidromous life histories, while others make incomplete transits between freshwater and seawater. The physiological mechanisms of osmoregulation are widely conserved among phylogenetically diverse species. Diadromous fishes moving between freshwater and seawater develop osmoregulatory mechanisms for different environmental salinities. Freshwater to seawater transition involves hormonally mediated changes in gill ionocytes and the transport proteins associated with hypoosmoregulation, increased seawater ingestion and water absorption in the intestine, and reduced urinary water losses. Fishes attain salinity tolerance through early development, gradual acclimation, or environmentally or developmentally cued adaptations. This chapter describes adaptations in diverse taxa and the effects of salinity on growth. Identifying common strategies in diadromous fishes moving between freshwater and seawater will reveal the ecological and physiological basis for maintaining homeostasis in different salinities, and inform efforts to conserve and manage migratory euryhaline fishes.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Freshwater to seawater transitions in migratory fishes
DOI 10.1016/B978-0-12-396951-4.00006-2
Year Published 2012
Language English
Publisher Elsevier
Contributing office(s) Coop Res Unit Leetown
Description 74 p.
Larger Work Type Book
Larger Work Title Fish Physiology
First page 253
Last page 326
Online Only (Y/N) N
Additional Online Files (Y/N) N