Influence of Photoperiod on the Number and Ultrastructure of Gill Chloride Cells of the Atlantic Salmon ( Salmo salar ) before and during Smoltification

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Lubin, Robert T., Rourke, A. W., Saunders, Richard L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1991
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f91-156; http://www.nrcresearchpress.com/doi/pdf/10.1139/f91-156

Atlantic salmon (Salmo salar) larger than 9 cm held under constant light since October had greater numbers of gill chloride cells in February compared with fish held under simulated natural photoperiod. By April, fish raised under simulated natural photoperiod were able to survive salinity tests, had a threefold increase in Na + /K + ATPase activity, and had increased chloride cell numbers. These increases and salinity tolerance did not occur in fish raised under constant light. Only fish reared under constant light developed apical pits with large and numerous microvilli.