Effects of dietary astaxanthin supplementation on fertilization and egg survival in Atlantic salmon ( Salmo salar L.)

Abstract

Atlantic salmon ( Salmo salar) were fed diets either with or without 100 mg kg −1 astaxanthin supplementation for different periods of time. Groups of fish were transferred from the unsupplemented diet to the supplemented diet at 3-month intervals from smoltification. The fish matured after either 2 1 2 or 3 1 2 years in salt water, and females produced eggs with astaxanthin concentrations ranging from 0 to 14.7 mg kg −1 wet weight. Eggs from 146 batches with differing pigmentation were incubated in triplicate in small cylindrical incubators, each with 250 eggs. Fertilization rate and survival to the eyed stage, from the eyed stage to hatching, and during the free embryo stage were studied in two seasons. Egg diameters and dry matter contents of the eggs were also recorded. Egg diameter increased with increasing age of the broodstock, but broodstock age had no significant effect on dry matter percentage. There were no differences in the mean survival of eggs from Seasons 1 and 2 from fertilization to hatching. Median survival at the eyed stage was 89.0% and 86.2%, and survival from the eyed stage to hatching was 92.3 and 93.7%, during Seasons 1 and 2 respectively. There was no relationship between the astaxanthin concentration of the eggs and the fertilization rates. Further, survival from fertilization to eyed stage or from eyed stage to hatching was not related to egg astaxanthin concentration. Free embryos that hatched from eggs with a high astaxanthin concentration did not perform better than those hatched from eggs with a low astaxanthin concentration. These findings of the present study indicate that astaxanthin is of little value as a measure of egg quality.