Effects of Hatchery Rearing on Brain Structures of Rainbow Trout, Oncorhynchus mykiss

Michael Marchetti, Gabrielle Nevitt

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In this study, we contrast brain morphology from hatchery and wild reared stocks to examine the hypothesis that in salmonid fishes, captive rearing produces changes in brain development. Using rainbow trout, Oncorhynchus mykiss , as a model, we measured eight regions of the salmonid brain to examine differences between wild and hatchery reared fish. We find using multiple analysis of covariance (MANCOVA), analysis of covariance (ANCOVA) and discriminant function analysis (DFA) that the brains of hatchery reared fish are relatively smaller in several critical measures than their wild counterparts. Our work may suggest a mechanistic basis for the observed vulnerability of hatchery fish to predation and their general low survival upon release into the wild. Our results are the first to highlight the effects of hatchery rearing on changes in brain development inbreak fishes.

Original languageAmerican English
JournalEnvironmental Biology of Fishes
StatePublished - Jan 1 2003


  • salmonidae
  • domestic fishes
  • brain size
  • neurobiology
  • conservation
  • discriminant function analysis


  • Earth Sciences
  • Environmental Sciences

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