Growth of different families of Atlantic salmon ( Salmo salar) under three experimental photoperiods

Abstract

Eight sibling groups of Atlantic salmon ( Salmo salar) parr were reared under three experimental photoperiods, 24L:0D, 16::8D and 8L:16D, from early January to late May. All families developed bimodality prior to or during the experiment. Between January and April growth rate was highest under 24L:0D and lowest under 8L:16D for both modes in all families. From April through May, growth rate was highest under 8L:16D or 16L:8D. The mean size of the families showed considerable variation and they ranked differently under the three photoperiods during the experiment, indicating genetic-environmental interaction in growth of presmolt Atlantic salmon.