Effects of Constant Day Length on Sexual Maturation and Growth of Atlantic Salmon ( Salmo salar) Parr

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Saunders, R. L., Henderson, E. B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1988
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f88-008; http://www.nrcresearchpress.com/doi/pdf/10.1139/f88-008

Atlantic salmon (Salmo salar) were reared for 6 mo from first feeding under four photoperiod regimes: LD 12:12, LD 16:8, LD 24:0, and simulated natural (LDN). Water temperature followed seasonal changes but was adjusted so as not to exceed 16 °C in summer or to fall below 6 °C in winter. Growth rates were highest in the LD 24:0 group during the first 3 mo; subsequently, the LD 16:8 fish grew faster than all others. Length–frequency distributions were skewed towards smaller sized fish in January. Sexually mature males were mainly in the lower halves of the length–frequency distributions; females and immature males were distributed throughout. The incidence of mature males was highest in the LDN group (67% of males) but reached high levels (44–58%) in the other groups.