Presentation Information
[R2P-07]Analysis of the optical path of light passing through the shell of the coccolithophore Braarudosphaera bigelowii
*Noboru FURUKAWA1, Naoki Hirane1 (1. Chiba University)
Keywords:
Braarudosphaera bigelowii,shell,optical path
Braarudosphaera bigelowii (hereinafter referred to as B. bigelowii) is a species of coccolithophore characterized by a calcite shell with a regular dodecahedral morphology. In this study, we conducted ray-tracing simulations to elucidate the optical properties associated with this shell morphology. The simulations were implemented using the Python programming language; the Trimesh library was used for mesh data manipulation and processing, while Raysect was employed for ray-tracing calculations. Additionally, NumPy was used for generating ray grids and performing numerical computations.
The shell of B. bigelowii consists of regular pentagonal units, each formed by the joining of five trapezoidal elements, with side lengths of several micrometers. As a whole, these pentagonal units assemble into a regular dodecahedral structure that encapsulates the cell.
Previous studies on samples involving the epitaxial growth of calcite on these shells have shown that the trapezoidal faces largely correspond to cleavage planes (Furukawa, 2004). Our simulation results indicate that light entering the B. bigelowii shell follows a nearly straight path to the opposite side, reflecting the shell's geometric form. However, light paths scattering outward were also observed at the shell's periphery. Optical micrographs of B. bigelowii (e.g., Ogino, 2024) reveal a shadow-like dark region surrounding the organism; B. bigelowii may utilize this dark region for some functional purpose.
The shell of B. bigelowii consists of regular pentagonal units, each formed by the joining of five trapezoidal elements, with side lengths of several micrometers. As a whole, these pentagonal units assemble into a regular dodecahedral structure that encapsulates the cell.
Previous studies on samples involving the epitaxial growth of calcite on these shells have shown that the trapezoidal faces largely correspond to cleavage planes (Furukawa, 2004). Our simulation results indicate that light entering the B. bigelowii shell follows a nearly straight path to the opposite side, reflecting the shell's geometric form. However, light paths scattering outward were also observed at the shell's periphery. Optical micrographs of B. bigelowii (e.g., Ogino, 2024) reveal a shadow-like dark region surrounding the organism; B. bigelowii may utilize this dark region for some functional purpose.