LAUSR

Abstract The lipid deposition pattern in economical crustaceans determines their flavor and commercial value. In this study, magnetic resonance imaging (MRI) was used to compare the lipid deposition patterns of three prawn species: red swamp crawfish (Procambarus clarkii), oriental river prawn (Macrobrachium nipponense), and whiteleg shrimp (Litopenaeus vannamei). To our knowledge, this is the first report of the determination of the total volume of lipid tissues in these prawn species by using three-dimensional (3D) images. The MRI results showed that the lipids were deposited as only visceral adipose tissue; the lipids were specifically deposited in the hepatopancreas and seldom in the gill and muscle tissues. The volume of lipid tissues was consistent with that measured after traditional dissection. The chemical analysis indicated that the lipid content of the hepatopancreas, muscle, and whole body of the red swamp crayfish was significantly higher than that of the oriental river prawn and whiteleg shrimp. We found that gonadal analysis with MRI is a non-destructive method to evaluate the plumpness of the tissues in live female red swamp crawfish, and the results were consistent with those of the histological analysis. The male whiteleg shrimps were starved, and MRI of the mesenteric plumpness of the hepatopancreas and biochemical analysis successfully detected changes in lipid metabolism in response to starvation. Thus, MRI can be used to study the plumpness of the hepatopancreas and gonadal tissues and physiological state of crustaceans and help us to understand the lipid deposition patterns in intact and live crustaceans.