ABSTRACT
Several salmonid species, including members of the genera Oncorhynchus, Salmo and Salvelinus, are anadromous and undergo a significant structural and functional transformation prior to migration to seawater. Smoltification consists of a number of independent, but co-ordinated developmental changes in the biochemistry, physiology, morphology and behaviour of the young salmon. The age and size at which smoltification occurs and its relative intensity differs among salmonid species. Desmoltification is generally viewed as a loss of important preparatory adaptations to marine life, including loss of hypo-osmoregulatory ability, critical metabolic adaptations, behavioural changes and major endocrine changes. According to Thorpe smoltification can be regarded as an alternative to the strategy of sexual maturation at the earliest opportunity.
