The growth of the screw dislocation of nacreous layer on Pteria penguin

In response to various environmental factors in offshore South China Sea, a group of microstructures of the screw dislocation are assembled in multiphase screw dislocations on the surface of the nacreous layer of Pteria penguin from the coastal waters of Hainan Island, China. The results of the transmission and scanning electronic microscope testing show that organic matter periodically secreted by epithelial histology of mantle of Pteria penguin pre-forms the original screw dislocation growth template in the form of film, along with its function to select, identify, and adhere to the amorphous calcium carbonate particles as the fine organic venations diffused in the epitaxial screw growth area. With the inducement and screw modulation of the organic film and venations, the amorphous calcium carbonate particles gradually evolve into the pseudohexagonal self. aragonite microsheet with long-range order and screw dislocation structure by location-selecting tropism and screw dislocation growth. Numerous micron-scale aragonite microsheets join in the cluster's interactive movement and screw dislocation self-assembly of the organic film, stacking forward along the axis C spirally and forming the nacreous layer with screw dislocation structure.