Ontogeny and Early Steps of the Calcification Process in Coralline Algae Lithophyllum corallinae (Florideophyceae, Rhodophyta)

Coralline algae (Rhodophyta, Florideophyceae) are one of the most abundant organisms in hard-bottom marine photic zone where they provide settlement substrates, structure and shelter on rocky substrates. also play important roles tropical reefs, both cementing corals together producing substantial amounts calcium carbonate. The ecological coralline environment related to biomineralization process that occurs cell walls. Currently, this group is receiving renewed attention from researchers different fields, especially due possible effects climate changes over its magnesium calcite skeleton. Despite attention, we still have poor information regarding first steps ontogeny calcification. aim study was describe earlier Lithophyllum corallinae development calcification process. Algae were collected at Vermelha Beach, Rio de Janeiro city. Adult crusts released spores settled microscope slides. germinating analyzed by Polarizing Light Microscopy, Scanning Electron Energy Dispersive Spectroscopy, Transmission Microscopy Atomic Force Microscopy. Results showed walls mineralization begins third spore division (8 cells specimen), evidenced light polarization, elemental composition hardness, restricted innermost part developing spore. Nanopores crystals identified, evidencing macromolecules occlusion, a feature prevent skeleton cracking high-energy environments. beginning could be size, availability organic matrix energy photosynthesis. All analysis confirmed lack outermost spore, which allows growth individual; but mainly indicates high level control process, representing relevant future studies calcification, including those testing scenarios.