Lipid Partitioning in the Hydrothermal Vent Shrimp Rimicaris exoculata

Abstract. This study examines the composition and partitioning of lipids in the alvinocarid shrimp Rimicaris exoculata from Mid-Atlantic hydrothermal vents. Juveniles and adults at different stages of reproductive development were dissected into abdomen, branchial and ovary/hepatopancreas tissues. Each of these tissues was analysed for total lipid and lipid class composition, and fatty acids and fatty alcohols were identified using GC and GC-MS. Adult and juvenile shrimp differ in the partitioning of lipids between tissues. Juveniles store lipids in the abdomen as wax ester droplets and may use phosphatidyl choline as an additional reserve. Adult shrimp use triglycerides as an energy store, and triglycerides and polar lipids accumulate in ovary and hepatopancreas tissue during reproductive development. The wax ester storage droplets of juvenile shrimp contain high concentrations of n-3 fatty acids, which are photosynthetically-derived and thought to be important for reproductive development in crustaceans. These n-3 fatty acids are concentrated in the ovary and hepatopancreas of adults compared to other tissues. The n-3 fatty acid content of these adult tissues is well within that estimated for whole juvenile shrimp, supporting the hypothesis that the n-3 fatty acids putatively required for adult reproduction are stored from the juvenile stage.