EFFECTS OF DIETARY ASTAXANTHIN SUPPLEMENTATION ON FERTILIZATION AND EGG SURVIVAL IN ATLANTIC SALMON (SALMO-SALAR L)

Atlantic salmon (Salmo salar) were fed diets either with or without 10 0 mg kg(-1) astaxanthin supplementation for different periods of time. Groups of fish were transferred from the unsupplemented diet to the s upplemented diet at 3-month intervals from smoltification. The fish ma tured after either 2 1/2 or 3 1/2 years in salt water, and females pro duced eggs with astaxanthin concentrations ranging from 0 to 14.7 mg k g(-1) wet weight. Eggs from 146 batches with differing pigmentation we re 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 broo dstock, but broodstock age had no significant effect on dry matter per centage. There were no differences in the mean survival of eggs from S easons 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 ha tching 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 e yed stage or from eyed stage to hatching was not related to egg astaxa nthin concentration. Free embryos that hatched from eggs with a high a staxanthin concentration did not perform better than those hatched fro m eggs with a low astaxanthin concentration. These findings of the pre sent study indicate that astaxanthin is of little value as a measure o f egg quality. (C) 1997 Elsevier Science B.V.