Supervisors: Liz Harper (Earth Sciences) and Lloyd Peck (British Antarctic Survey)
Importance of the area of research:
The ability to make a shell has had a profound impact on the evolution of a number of important invertebrate taxa. For example, biomineralized hard parts have allowed offensive and defensive adaptations to evolve and provided the means to hermetically seal vulnerable soft parts away from difficult environmental conditions (as well as improving the quality of the fossil record immeasurably). Despite the importance of the evolution of the shell both to our understanding of evolution and also for the resistance to future challenges from environmental change, surprisingly little is known about the costs of making a shell and the current estimates of the energetic cost of depositing calcium are coarse (Palmer 1992). A proper understanding of these costs would improve understanding of a wide range of questions, such as why some organisms use calcite and others aragonite (or both), why so many very different microstructural arrangements have evolved and also the alteration in ‘costs’ for shelled organisms moving into fresh or deep sea waters where biomineralization may be more difficult to achieve.
The project will use molluscs as model organisms and use a range of techniques to quantify both the mineral and organic matrix component of the shells. Although previous estimates have concentrated almost entirely on the costs of making the organic fraction of the shell, we also seek to quantify the costs involved with pumping and saturating fluids to the site of shell formation.
What the student will do:
The student will experimentally manipulate living molluscs, using a range of marking techniques to measure shell growth and quantify the deposition of Ca2+ within the shell and also to measure the concentration of Ca2+ in the fluids from which the shell crystallises. Analyses of species depositing calcite and/or aragonite will be made allowing models of shell construction costs to be developed for taxa with different shell constructions, and to allow more accurate predictions of changes in future costs in acidified oceans to be made.
Please contact the lead supervisor directly for further information relating to what the successful applicant will be expected to do, training to be provided, and any specific educational background requirements.
Palmer, A. R. 1992. Calcification in marine molluscs: How costly is it? Proceedings of the National Academy of Sciences (USA) 89:1379-1382.
Peck, L.S., A. Baker& L. Z. Conway,.1996. Strontium labelling of the shell of the Antarctic limpet Nacella concinna. J. Moll. Stud. 62: 315-325.
Weiner, S. & L. Addadi, 2011. Crytsallization pathways in biomineralization. Annu. Rev. Material. Res. 41: 21-40.
Follow this link to find out about applying for this project.