Every fall the lab migrates to the Credit River (off of Lake Ontario) to collect Chinook salmon, including males from both alternative reproductive tactics. The hooknose males are large dominant males that mature at 4-5 years of age whereas the jack males are small sneaker males that mature at 2 years of age. Recent genomic work in the lab has shown significant differences in the major histocompatibility complex genes between the two male tactics which may have important implications for fish culture as jacks are rarely used but may represent additional functional genetic diversity.
