DESCRIZIONE
The present invention relates to a fish feed comprising dioxabicyclo[3.3.0] octane derivates, in particular selected sesame lignans, and a vegetable oil or oil mixture comprising at least one 18-carbon chain omega-3 fatty acid. The dioxabicyclo[3.3.0] octane derivate will induce a desaturation and elongation of the 18-carbon chain fatty acid in the fish muscle into longer carbon chain polyunsaturated fatty acids.