Bioapatite in shark centra studied by wide-angle and by small-angle X-ray scattering. Issue 194 (21st September 2022)

• Record Type: Journal Article
• Authors: Park, J. S.; Almer, J. D.; James, K. C.; Natanson, L. J.; Stock, S. R.
• Is Part Of: Journal of the Royal Society interface. Volume 19:Issue 194(2022)
• Publication Date: 2022-09-21
• Subjects: shark -- mineralized tissue -- centrum -- small-angle X-ray scattering -- wide-angle X-ray scattering -- X-ray diffraction; Physical sciences -- Research -- Periodicals; Life sciences -- Research -- Periodicals; Interdisciplinary research -- Periodicals; 570.5
• DOI: 10.1098/rsif.2022.0373
• Languages: English
• ISSNs: 1742-5689

Abstract

Abstract : Members of subclass Elasmobranchii possess cartilage skeletons; the centra of many species are mineralized with a bioapatite, but virtually nothing is known about the mineral's organization. This study employed high-energy, small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS, i.e. X-ray diffraction) to investigate the bioapatite crystallography within blocks cut from centra of four species (two carcharhiniform families, one lamniform family and 1-ID of the Advanced Photon Source). All species' crystallographic quantities closely matched and indicated a bioapatite closely related to that in bone. The centra's lattice parameters a and c were somewhat smaller and somewhat larger, respectively, than in bone. Nanocrystallite sizes (WAXS peak widths) in shark centra were larger than typical of bone, and little microstrain was observed. Compared with bone, shark centra exhibited SAXS D -period peaks with larger D magnitudes, and D -period arcs with narrower azimuthal widths. The shark mineral phase, therefore, is closely related to that in bone but does possess real differences which probably affect mechanical property and which are worth further study.