For the fertilization tests 10 g of eggs were transferred into petri
dishes and 5 ml of a 4 °C cold fertilization solution (60 mM NaHCO3,
20 mM glycin, pH 9) was added. Ten g of eggs was fertilized with
semen stored for 3 days in SMIS or in SMIS containing linoleic acid or
arachidonic acid. Palmitic acid and arachidic acid were not tested due
to limited availability of material. Sperm/egg ratios of 3.0–
4×105 spermatozoa/egg were used. After 2 to 3 min the eggs were
rinsed and incubated in flow-through incubators in the fish farm
Kreuzstein. Fertilization rate was determined as the number of eyed
embryos in relation to the total number of eggs after 30 days