title: Calcium sulfate hemihydrate is the inorganic mineral in statoliths of Scyphozoan medusae (Cnidaria).
abstract: 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.
authors.affiliation: University of Duisburg-Essen, Institute of Inorganic Chemistry, Universitaetsstrasse 5-7, D-45117, Essen, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Becker
authors.forename: Ilka
authors.initials: I
authors.lastname: Sötje
authors.forename: Carsten
authors.initials: C
authors.lastname: Paulmann
authors.forename: Felix
authors.initials: F
authors.lastname: Beckmann
authors.forename: Tilman
authors.initials: T
authors.lastname: Donath
authors.forename: Roland
authors.initials: R
authors.lastname: Boese
authors.forename: Oleg
authors.initials: O
authors.lastname: Prymak
authors.forename: Henry
authors.initials: H
authors.lastname: Tiemann
authors.forename: Matthias
authors.initials: M
authors.lastname: Epple
mesh_terms: D000818:Animals; D002133:Calcium Sulfate / Q000737:chemistry*; D003063:Cnidaria / Q000033:anatomy & histology / Q000737:chemistry*
chemical_list: D002133:Calcium Sulfate