Iodine disinfection of sea trout, Salmo trutta (L.), eggs and the affect on egg surfaces

Abstract

The aim of the research was to investigate the impact iodine solution disinfection had on Salmo trutta (L.) egg survival rates during incubation, and to determine the effect of the disinfection procedure on egg shells using scanning microscopy. The study groups were bathed in a Desamar K30 solution at a concentration of 100 ml per 10 dm-3 for 10 m once after the eggs had hardened and four times after the eyed stage. Egg samples for scanning analyses were collected on day 30 of incubation at the eyed stage after the first bath in the iodophor solution, and then at the end of incubation. Egg surface images were analyzed for the number of bacteria, the presence of hyphae, and the egg surface area covered with sediments. No statistically significant differences were noted in embryo survival rates in the groups that were disinfected. The highest number of bacteria was observed on egg surfaces which had not been disinfected prior to hatching. A significant amount of sediment was observed on the eggs during incubation. On day 90 of incubation, all of the egg surfaces were covered with sediments. Disinfection was not noted to have had a significant impact on the presence of hyphae. Iodophor preparations can be used for routine disinfection of trout eggs; however, other means of disinfection should be applied before the eyed egg stage.