Calcification in Coccolithophorids

Abstract

Coccolithophorids, a group of monocellular, photosynthetic marine algae belonging to the class of Haptophyceae Parke and Dixon, are characterized by their ability to form calcified bodyscales, so-called coccoliths. These coccoliths are fine round or oval structures which, on analysis, are composed of CaCO3. The morphology of coccoliths is species-specific and enormous variations in sizes and shapes has been described (cf. Black, 1965; Okada and Mclntyre, 1977). Fossil coccoliths are important biostratigraphical tools. Geographically, nowadays, these coccolithophorids have a wide area of distribution: they have been found in tropical, subtropical as well as in arctic waters (Klaveness and Paasche, 1979) and contribute to a considerable extent to the formation of extensive lime ores in the deepsea. Also in the geological past the coccolithophorids have been partly responsible for mass accumulations of CaCO3, especially in the Cretaceous.