Lipid Partitioning in the Hydrothermal Vent Shrimp Rimicaris exoculata

Abstract

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.

Identification of minor fatty acids and various nonmethylene‐interrupted diene isomers in mantle, muscle, and viscera of the marine bivalve Megangulus zyonoensis

“…The unusual isomers 20:4n-4 and 20:4n-1 were found in bivalves for the first time. The unusual isomer 20:4n-4 has been detected only in the diatom Stauroneis amphioxys (19) and the shrimp Rimicaris exculpate (20) together with 20:4n-6 and 20:4n-3, but 20:4n-1 probably has not been reported previously from living organisms. Among the isomers of 21:4, the proportion of 21:4n-6 in the mantle and viscera was higher than in muscle, at 55.6 to 59.3%.…”

“…Although 20:4n-6, 20:4n-4, and 20:4n-3 have been reported from marine invertebrates (19,20), 20:4n-1 probably has not been observed in any living organisms. Megangulus zyonoensis was rich in 20:4n-1, at about 11% of the total isomers of 20:4, in viscera lipids.…”

Spatial and temporal patterns in development of eggs in the vent crab Bythograea thermydron

“…Therefore, variation in surface production may have a direct effect on the nutritional environment to which the larvae are exposed and, thus, an indirect effect on the seasonality of reproductive activity in the adults. For example, a recent study on Rimicaris exoculata from mid-Atlantic hydrothermal vents presented evidence that photosynthetically-derived Ω-3 fatty acids, thought to be necessary for adult reproduction, are originally acquired during the juvenile stage in this shrimp (Allen et al 2001).…”

Seasonality and zonation in the reproductive biology and population structure of the shrimp Alvinocaris stactophila (Caridea: Alvinocarididae) at a Louisiana Slope cold seep

“…Collection of further seasonal samples for lipid analysis would be required to examine this possibility. Studies of other alvinocaridid shrimp inhabiting chemosynthetic environments suggest that individuals may sequester a lifetime supply of such phytoplankton-derived compounds during their planktotrophic larval stage (Pond et al 2000, Allen et al 2001). This does not preclude adults from perceiving seasonal variations in the supply of such compounds and using that signal as a zeitgeber to synchronise gametogenic cycles.…”