Table 15-6. The Major Fatty Acids of the 3-Day-Old 

 Brine Shrimp Diet and 25 and 58-Day-Old Silversides 



3-day-old brine shrimp diet may lead to critical nutritional problems if used in 

 a long term study. 



When compared to the wild fish (Table 1 5-5), the cultured fish have a far 

 lower coS fatty acid level and much higher level of the co6 acids. The co3/c<j6 

 ratio of the wild fish lipid was 8.0, more than two times the cultured fish 

 levels. The wild fish fatty acid profile was similar to the egg and 2-day-old yolk 

 sac fry values, as would be expected. In the wild fish the fatty acids 20:5c<j3 

 and 22:6c«j3 represented about 40 percent of the total fatty acid composition. 

 Preferably, the cultured fish should resemble the wild juvenile fish in our 

 experiments. 



Artificial Diets 



Since the amino acid profiles of the Atlantic salmon and wild silversides 

 were comparable, a commercial salmon diet was tried in the preliminary 

 evaluation of the artificial diets. Compared to the brine shrimp fed fish, growth 

 and survival in the test diet fed group was very poor. Fish on the salmon type 

 diet exhibited some scoliosis. Two factors which could have contributed to this 



223 



