The ultrastructure of coccoliths from the marine algaEmiliania huxleyi(Lohmann) Hay and Mohler: an ultra-high resolution electron microscope study

Publisher Website
Google Scholar
Abstract
The calcite coccoliths from E. huxleyi (Lohmann) Hay and Mohler were studied; the 2 different types of structure, one in the upper elements and the other in the basal plate, or lower element are described. The former consisted of small, microdomain structures of 300-500 .ANG. (1 .ANG. = 10-10 m) in length with no strong orientation. At places along these elements, and particularly in the junction between stem and head pieces, triangular patterns of lattice fringes were observed indicating multiple nucleation sites in the structure. In contrast, the lower element consisted of a very thin single crystalline sheet of calcite which could be resolved into a 2 dimensional lattice image, shown by a computer program that is capable of simulating electron diffraction patterns and lattice images to be a zone of calcite. A possible mechanism for these growth patterns in the formation of coccoliths is discussed, together with the relevance of such mechanisms to biomineralization generally.