HATCHERY PERFORMANCE OF 6 ATLANTIC SALMON STOCKS FROM FRY TO SMOLT

Atlantic salmon (Salmo salar) from four Penobscot River, Maine, brood stocks (two wild and two captive) and two landlocked brood stocks (Gra nd Lake, Maine, and Lake George, New York) were evaluated in hatchery tests to measure differential performance characteristics. Each stock was received as eyed eggs and cultured under standardized rearing cond itions through 16 months. Penobscot stocks did not differ in growth ra te or time of smoltification but did differ in frequency of six of sev en body abnormality traits. Domestication effects on postyearling weig hts and smolt ATPase levels were detected in Penobscot stocks. The Gra nd Lake landlocked stock had a higher growth rate after 245 d and was heavier than Penobscot stocks after 280 d (36%) and 480 d (58%). Altho ugh differences among the Penobscot stocks were small and generally no nsignificant, the presence of domestication effects on 17-month weight and Na+,K+-ATPase indicates that progeny from fish held in the hatche ry for four generations exhibited different hatchery performance chara cteristics than progeny from sea-run parents.