Comparisons of reproductive function and fatty acid fillet quality between triploid and diploid farm Atlantic salmon (Salmo salar)

Triploidy could prevent escaped farm salmon breeding in the wild, while also improving nutrient quality within farmed fillets. Despite these potential advantages, triploid Atlantic salmon have not been widely used in aquaculture, and their reproductive function has yet to be fully evaluated. Here, we compare reproductive function and fillet composition between triploid and diploid farm salmon under standard aquaculture rearing conditions. We show that female triploids are sterile and do not develop gonads. In contrast, males produce large numbers of motile spermatozoa capable of fertilising wild salmon eggs. However, compared with diploids, reproductive development and survival rates of eggs fertilised by triploid males were significantly reduced, with less than 1% of eggs sired by triploid males reaching late eyed stages of development. Analyses of fillets showed that total lipid and fatty acid quantities were significantly lower in triploid compared to diploid Atlantic salmon fillets....