Bioaccumulation and Bioconversion of Dietary Labeled Fatty Acids in Artemia and Winter Flounder (Pseudopleuronectes americanus)

Abstract

One-day-old Artemia were fed for 14 d on nine different rice bran diets, most containing either [1-14C]18:2 ω6 or [1-14C]18:3 ω3, along with various nonlabeled fatty acids. The 15-d-old Artemia were then fed as labeled diets to winter flounder (Pseudopleuronectes americanus). Although 18:2 ω6, 18:3 ω3, and 20:5 ω3 were primarily bioaccumulated, all 15-d-old Artemia groups contained some22:6 ω3, even when it was not present in the diet. Therefore, the 15-d-old Artemia had bioconverted small amounts of 18:2 ω6 and 18:3 ω3 to 20:5 ω3 and 22:6 ω3. The bioconversion rate was substantially reduced when either 20:5 ω3 or 22:6 ω3 was present in the diet. When fed the 15-d-old Artemia, the winter flounder accumulated 20:5 ω3 and 22:6 ω3 and also bioconverted some of the 18:3 ω3 to 20:5 ω3 and 22:6 ω3. Those fish fed diets that contained lower levels of 20:5 ω3 and 22:6 ω3 contained higher levels of radioactively labeled 20:5 ω3 and 22:6 ω3. When 20:5 ω3 and 22:6 ω3 were present from the diet, the radioactivity generally accumulated in the 20:4 ω3 and 20:5 ω3 fatty acids.