Abstract
Closely related species of fish often exhibit different migration patterns. Even within species, anadromous and resident populations can be found in a diverse number of taxa. Although several environmental factors that regulate behavioral and physiological changes associated with fish migration have been identified, the genetic mechanisms underlying the variation in the ability to respond to these environmental cues in fishes that show different migratory behaviors are not well known. The three-spined stickleback Gasterosteus aculeatus (Linnaeus 1758) is a good model system for elucidation of the genetic basis for variation in migratory behaviors and other physiological changes associated with migration. First, the three-spined stickleback exhibits great inter-population variation in migration patterns. Second, genetic and genomic tools are now available for studying this species. In the present study, variation in the migration patterns among G. aculeatus populations and the recent progress in our understanding of the genetic and physiological basis for variation in traits important for G. aculeatus migration are reviewed.