Influences of coral intra-skeletal organic matrix on calcium carbonate precipitation

Corals are among the most important calcium carbonate mineralizers and form the main structures of the reefs, which provide an important socio-economical support. Despite this, and the fact the is quite generally accepted that coral mineralization is a biological controlled process, few studied have so far addressed the role of the intra-skeletal organic matrix in the calcification process. This chapter makes a scientific path on what is known on the biological control of coral mineralization describing the more relevant studies. The sections are sequenced with the aim to guide the readers to be conscious of the importance of the organic matrix in the mineralization process that is finally illustrated through a series of experiments in vivo and in vitro. Accordingly the chapter presents an overview on coral biomineralization, anatomy and physiology, skeleton microsctructure, tissue-skeleton, minor element distribution, organic matrix, biomineralization proteins and finally calcium carbonate precipitation in the presence of coral organic matrix.