Lipid Composition of Juvenile Carpet Clams (Paphia textile) Fed Mixed Microalgal Diets

Lipid composition detected in juveniles of the carpet clams Paphia textile, and three feeding strains of microalgae were investigated. Lipids were extracted via the Folch method and analyzed through gas chromatography coupled with a mass spectrometry detector after methylation. The results demonstrated seven classes of lipids mainly alkanes and fatty acids (FA), accounting for more than 97% of the total lipids. Palmitic acid (C16:0), linolenic acid (C18:3n3), elaidic acid (C18:1n9t), linoleic acid (C18:2n6), and stearic acid (C18:0) were the characteristic FA in P. textile and Tetraselmis helgolandica. A large amount of PUFA precursors in the synthesis of T. helgolandica were identified, such as linolenic acid (18:3n-3) with a relative content of 14.37% and linoleic acid (18:2n-6) with a relative content of 9.56%. Although the composition of LCFA in P. textile was more similar to those in Isochrysis galbana and Chaetoceros muelleri, it was shown that T. helgolandica can also meet the lipid nutrition needs of P. textile with a high PUFA relative content of 42.19%, and it was an excellent diet for the juvenile carpet clam of P. textile. It is recommended to add a mixed diet of I. galbana and C. muelleri when feeding mainly T. helgolandica.