Calcium sulfate hemihydrate is the inorganic mineral in statoliths of Scyphozoan medusae (Cnidaria).
Scyphomedusae use inorganic crystals (statoliths) for gravity sensing. The organs which contain the statoliths are called rhopalia. Rhopalia of five different species of the three different orders of the class Scyphozoa were studied with high-end solid-state chemical methods to elucidate the crystallographic nature of the biomineral: synchrotron powder diffraction, synchrotron single-crystal diffraction, synchrotron microtomography, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Each rhopalium contains a large number of statoliths in an ordered way. The statoliths of all species consist of calcium sulfate hemihydrate, a water-deficient phase. This is remarkable for sea-living organisms consisting mostly of water. The phylogenetic relationships within the class Scyphozoa are discussed.
Becker
Alexander
A
University of Duisburg-Essen, Institute of Inorganic Chemistry, Universitaetsstrasse 5-7, D-45117, Essen, Germany.
Sötje
Ilka
I
Paulmann
Carsten
C
Beckmann
Felix
F
Donath
Tilman
T
Boese
Roland
R
Prymak
Oleg
O
Tiemann
Henry
H
Epple
Matthias
M
D000818:Animals; D002133:Calcium Sulfate / Q000737:chemistry*; D003063:Cnidaria / Q000033:anatomy & histology / Q000737:chemistry*
D002133:Calcium Sulfate