Abstract
In sea urchin teeth, the keel plays an important structural role, and this paper reports results of microstructural characterization of the keel of Lytechinus variegatus using two noninvasive synchrotron x-ray techniques: x-ray absorption microtomography (microCT) and x-ray diffraction mapping. MicroCT with 14 keV x-rays mapped the spatial distribution of mineral at the 1.3 µm level in a millimeter-sized fragment of a mature portion of the keel. Two rows of low absorption channels (i.e., primary channels) slightly less than 10 µm in diameter were found running linearly from the flange to the base of the keel and parallel to its sides. The primary channels paralleled the oral edge of the keel, and the microCT slices revealed a planar secondary channel leading from each primary channel to the side of the keel. The primary and secondary channels were more or less coplanar and may correspond to the soft tissue between plates of the carinar process. Transmission x-ray diffraction with 80.8 keV x-rays and a 0.1 mm beam mapped the distribution of calcite crystal orientations and the composition Ca1−x Mg x CO3 of the calcite. Unlike the variable Mg concentration and highly curved prisms found in the keel of Paracentrotus lividus, a constant Mg content (x = 0.13) and relatively little prism curvature was found in the keel of Lytechinus variegatus.
Similar content being viewed by others
References
K Märkel P Gorny K Abraham (1976) ArticleTitleMicroarchitecture of sea urchin teeth. Fortschritte der Zoologie 24 103–114
K Märkel (1969) ArticleTitleMorphologic der Seeigelzähne: II. Die gekielten Zähne der Echinacea (Echinodermata, Echinoidea). Z Morph Tiere 66 1–50
DM Candia Carnevali F Bonasoro G Melone (1991) ArticleTitleMicrostructure and mechanical design in the lantern ossicles of the regular sea-urchin Paracentrotus lividus: a scanning electron microscope study. Bull Zool 58 1–42
RZ Wang L Addadi S Weiner (1997) ArticleTitleDesign strategies of sea urchin teeth: Structure, composition and micromechanical relations to function. Philosophical Transactions of the Royal Society (London) B 352 469–480 Occurrence Handle10.1098/rstb.1997.0034 Occurrence Handle1:STN:280:ByiA3cnlt1c%3D Occurrence Handle12869329
CD West (1937) ArticleTitleNote on the crystallography of the echinoderm skeleton. Journal of Paleontology 11 458–459
DM Raup (1966) The endoskeleton, R.A. Boolootián (Eds) Physiology of Echinodermata: Wiley New York 379–395
K Towe (1967) ArticleTitleEchinoderm calcite: Single crystal or polycrystalline aggregate. Science 157 148–150
G Donnay DL Pawson (1969) ArticleTitleX-ray diffraction studies of echinoderm plates. Science 166 1147–1150
HU Nissen (1969) ArticleTitleCrystal orientation and plate structure in echinoid skeletal units. Science 166 1150–1152
DJ Veis TM Alberger J Clohisy M Rahima B Sabsay A Veis (1986) ArticleTitleMatrix proteins of the teeth of the sea urchin Lytechinus variegatus. Journal of Experimental Zoology 240 35–46 Occurrence Handle1:CAS:528:DyaL28Xmt1ejtb8%3D Occurrence Handle3095485
A Berman L Addadi S Weiner (1988) ArticleTitleInteractions of sea-urchin skeleton macromolecules with growing calcite crystals — a study of intracrystalline proteins. Nature 331 546–548 Occurrence Handle1:CAS:528:DyaL1cXht1OjtL8%3D
A Berman L Addadi Å Kvick L Leiserowitz M Nelson S Weiner (1990) ArticleTitleIntercalation of sea urchin proteins in calcite: a study of a crystalline composite material. Science 250 664–667 Occurrence Handle1:CAS:528:DyaK3MXhtVGrtrY%3D
A Berman J Hanson L Leiserowitz TF Koetzle S Weiner L Addadi (1993) ArticleTitleBiological control of crystal texture: a widespread strategy for adapting crystal properties to function. Science 259 776–779
E Beniash J Aizenberg L Addadi S Weiner (1997) ArticleTitleAmorphous calcium carbonate transforms into calcite during sea urchin larval spicule growth. Proceedings of the Royal Society (London) B264 461–465
SR Stock T Dahl J Barss A Veis K Fezzaa WK Lee (2002a) ArticleTitleMineral phase microstructure in teeth of the short spined sea urchin (Lytechinus variegatus) studied with x-ray phase contrast imaging and with absorption microtomography. Advances in X-ray Analysis 45 133–138 Occurrence Handle1:CAS:528:DC%2BD38XptVOqtbo%3D
SR Stock T Dahl J Barss A Veis JD Aimer (2002b) ArticleTitleX-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth. Journal of Structural Biology 139 1–12 Occurrence Handle10.1016/S1047-8477(02)00500-2 Occurrence Handle1:CAS:528:DC%2BD3sXisl2itL4%3D
Y Wang F De Carlo D Mancini I McNulty B Tieman J Bresnahan I Foster J Insley P Lane G von Laszewski C Kesselman M-H Su M Thiebaux (2001) ArticleTitleHigh-throughput X-ray microtomography system at the Advanced Photon Source. Rev Sci Instrum 72 2062–2068 Occurrence Handle10.1063/1.1355270 Occurrence Handle1:CAS:528:DC%2BD3MXitlOjsLw%3D
Hammersley AP (1998) FIT2D V9.129 Reference Manual V3.1. ESRF Internal Report ESRF98HA01T.
AP Hammersley SO Svensson A Thompson (1994) ArticleTitleCalibration and correction of spatial distortions in 2D detector systems. Nuclear Instruments and Methods A346 312–321
AP Hammersley SO Svensson A Thompson H Graafsma Å Kvick JP Moy (1995) ArticleTitleCalibration and correction of distortions in 2D detector systems. Review of Scientific Instruments SRI-94 66 2729–2733 Occurrence Handle10.1063/1.1145618 Occurrence Handle1:CAS:528:DyaK2MXksVGgsbY%3D
AP Hammersley SO Svensson M Hanfland AN Fitch D Häusermann (1996) ArticleTitleTwo-Dimensional Detector Software: From Real Detector to Idealised Image or Two-Theta Scan. High Pressure Research 14 235–248
JD Haase A Guvenilir JR Witt SR Stock (1998) ArticleTitleX-ray Microbeam Mapping of Microtexture Related to Fatigue Crack Asperities in Al-Li 2090. Acta Mater 46 4791–4799 Occurrence Handle10.1016/S1359-6454(98)00118-9 Occurrence Handle1:CAS:528:DyaK1cXls12rsr4%3D
BD Cullity SR Stock (2001) Elements of X-ray Diffraction, 3rd ed. Prentice-Hall Englewood Cliffs, NJ
NIST, Tables of X-ray Mass Attenuation Coefficients and Mass Energy Absorption Coefficients from 1 keV to 20 MeV for Elements Z=1 to 92 and 48 Additional Substances of Dosimetric Interest. NISTIR 5632, July 2001
GR Davis (1997) ArticleTitleImage quality in x-ray microtomography. SPIE 3149 213–221
JN Weber (1969) ArticleTitleThe incorporation of magnesium into skeletal calcites of echinoderms. Am J Sci 267 537–566 Occurrence Handle1:CAS:528:DyaF1MXktlahtLc%3D
JH Schroeder EJ Dwornik JJ Papike (1969) ArticleTitlePrimary protodolomite in echinoid skeletons. Geological Society of America Bulletin 80 1613–1616 Occurrence Handle1:CAS:528:DyaF1MXks1ehtro%3D
KJ Davis PM Dove JJ De Yorero (2000) ArticleTitleThe role of Mg2+ as an impurity in calcite growth. Science 290 1134–1137 Occurrence Handle10.1126/science.290.5494.1134 Occurrence Handle1:CAS:528:DC%2BD3cXotVChsro%3D Occurrence Handle11073446
A Snigirev V Kohn I Snigireva B Lengeler (1996) ArticleTitleA compound refractive lens for focusing high-energy X-rays. Nature 384 49–51 Occurrence Handle10.1038/384049a0 Occurrence Handle1:CAS:528:DyaK28XmvVWrtLc%3D
B Lengeler C Schroer J Tümmler B Benner M Richwin A Snigirev I Snigireva M Drakopoulos (1999) ArticleTitleImaging by parabolic refractive lenses in the hard x-ray range. Journal of Synchrotron Radiation 6 1153–1167 Occurrence Handle10.1107/S0909049599009747
T Weitkamp O Chubar M Drakopoulos A Souvorov A Snigirev I Snigireva F Günzler C Schroer B Lengeler (2001) ArticleTitleRefractive lenses as a beam diagnostics tool for high-energy synchrotron radiation. Nuclear Instruments & Methods A 467–468 248–251
MAR Research, www.marresearch.com
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Stock, S., Barss, J., Dahl, T. et al. Synchrotron X-ray Studies of the Keel of the Short-Spined Sea Urchin Lytechinus variegatus: Absorption Microtomography (microCT) and Small Beam Diffraction Mapping . Calcif Tissue Int 72, 555–566 (2003). https://doi.org/10.1007/s00223-002-1037-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00223-002-1037-2