title: The production of gynogenetic Atlantic salmon, Salmo salar L.
abstract: The production of Atlantic salmon gynogenomes by the combined use of a novel method for sperm irradiation and differently timed high hydrostatic pressure shocks is described. Sperm solutions were exposed to UV irradiation in a temperature-controlled flow-through device. Eggs fertilised with such sperm were exposed to shocks of 9500 psi at 30 min or approximately 7 h after fertilisation in order to produce meiotic and mitotic gynogenomes respectively. Yields of meiotic gynogenomes were generally high (up to 95%); those of mitotic gynogenomes were lower (range 2-20%). Analyses of the offspring by ploidy status and fingerprinting confirmed their gynogenetic origin. Small numbers of mitotic gynogenetic fish were grown on for 2 years in fresh and salt water. S1/S2 ratios were lower in gynogenetic fish and mean age at maturity was greater. Of the presumptive gynogenetic fish subjected to destructive sampling (n = 87) all were female.
authors.affiliation: SOAFD Marine Laboratory, Victoria Road, PO Box 101, AB9 8DB, Aberdeen, Scotland, UK.
authors.forename: R
authors.initials: R
authors.lastname: Johnstone
authors.forename: R J
authors.initials: RJ
authors.lastname: Stet