R4: Mineral sciences of the Earth surface

[R4P-02] Crystallographic characteristics of vaterite in fish otolith

[Presentation award entry]

*Gen Takahashi¹, Taiga Okumura¹, Michio Suzuki², Toshihiro Kogure ¹ (1. Univ. Tokyo, Sci., 2. Univ. Tokyo, Agri.)

Keywords:biomineralization, calcium carbonate, otolith

Calcium carbonate crystals, called otoliths, are found in the inner ear of fish. Bony fishes have three otoliths, and they are often different crystal polymorphs: lapillus and saggita are aragonite, and asteriscus is vaterite. The reason why vaterite, a metastable phase, can form and exist stably in fish otoliths is not known, but it is thought that processes unique to biomineralization play an important role. In this research, the crystallographic characteristics of vaterite in fish otoliths were investigated to elucidate the formation mechanism.