The occurrence of wax esters in crustaceans from the North-east Atlantic Ocean

The lipids of 2 species and 1 group of copepods, 4 species of euphausiids, 2 species of mysids, and 6 species of decapods, taken from different depths in the North-eastern Atlantic Ocean and Western Mediterranean Sea, have been analysed specifically for their wax ester content. The mid-water animals living below 500 m contained large amounts of wax ester (30 to 80% total lipid), while those animals living in the upper 600 to 700 m or on the sea floor had only small wax ester fractions (5 to 10% total lipid). It is suggested that the wax esters are laid down by those animals living in areas of low food density, where energy conservation is important, partly to achieve a more neutral buoyancy. In addition, it would appear that wax esters can function as energy reserves.