Survie in vitro et post mortem des gametes de truite fario (Salmo trutta fario)

Abstract

Post mortem continuation of fertility of the gametes in the trout Salmo trutta fario has been investigated in order to gather more information on the possibility of using ova and sperm from genitors killed accidentally. The percentage of eggs fertilized at 200 day-degrees was used as a measure of the fertility of the gametes left post mortem in the genital tracts of animals kept at 4 °C after killing, in air or water; the measures were compared with those of gametes kept in vitro, at 4 °C also. Gametes taken periodically from live fish during the experiment were used as controls.Gametes kept in the body of killed genitors survive only a few hours and show a significant drop after 12 h and 6–8 h for sperm and live respectively, with no detectable difference between fish kept in water or in air. Gametes kept in vitro maintain their fertility at 51–90% after 72 h (control = 96%) and at 80% after 14 days (control = 97%) for ova and sperm respectively. The fertilizing capacity of control sperm taken from live fish did not vary throughout the experiment.[Journal translation]