Mechanical properties of the exoskeleton of Indian ocean deep-sea hydrothermal vent Austinograea rodrigaez

초록

The hydrothermal vent is a region where a new oceanic crust is formed by the magma at the interface of the deep-sea bed with unusual hydrothermal ejecta ranging from 0 to 400°C. To maximize survival in these environments, organisms might have developed a robust exoskeleton over millions of years. To understand the exoskeleton evolution of crustaceans in hydrothermal vents, we compared the constitutive and structural features of the characteristic exoskeleton of Austinograea rodriguez in the hydrothermal vents and those of Japanese swimming crab (Charybdis japonica) and Pea pebble crab (Philyra pisum) in shallow water environments. We used Scanning Electron Microscope(SEM), Energy Dispersive X-ray(EDX), and X-Ray Diffraction(XRD) to analyze the hierarchy of the exoskeleton, and Inductively Coupled Plasma Optical Emission Spectrometer(ICP-OES) was used for Mg/Ca ratio analysis for chemical structure of exoskeleton. The exoskeleton of A. rodriguez consisted of multi-layer structures with different composition and structure of each layer. The coastal species also had a multi-layer structure, but the structure and composition each layer were the same. The results suggest that the exoskeleton of deep-sea crustaceans in the hydrothermal vents have evolved complex structures to endure high temperatures and pressures.