Skip to main content
Article thumbnail
Location of Repository

Phase transitions of wax esters adjust buoyancy in diapausing Calanoides acutus\ud \ud

By David W. Pond and Geraint A. Tarling


We study the composition and biophysical properties of wax esters extracted from the Antarctic copepod, Calanoides acutus, to explore if these factors adjust buoyancy in diapausing copepods. Levels of wax ester in the copepods were correlated with depth, with deeper animals containing higher amounts. An unsaturation index was used to determine the proportions of polyunsaturated wax esters in the oil sac of the copepods. The proportion of polyunsaturated wax ester in copepods that had descended to depth was always close to 50% and attributable to high amounts of the diatom biomarker fatty acid 20:5(n-3) contained in these storage lipids. High-pressure differential scanning calorimetry indicated that wax esters with such high levels of unsaturation exhibited unusual properties, changing from a liquid to a solid phase at pressures and temperatures below 500 m in the ocean. The dense, solid wax esters reduce the overall buoyancy of the lipid-rich copepods at depth and help facilitate neutral buoyancy. The composition of wax esters is a key factor in buoyancy control in these organisms during diapause

Topics: Marine Sciences, Biology and Microbiology
Publisher: American Society of Limnology and Oceanography
Year: 2011
DOI identifier: 10.4319/lo.2011.56.4.1310
OAI identifier:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • (external link)
  • (external link)
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.