Ariani, Balassone et al. 1999
Ariani, Balassone et al. 1999
ARIANI, A. P., G. BALASSONE, G. MIRONE & K.J. WITTMANN, 1999: Experimentally induced mineral phase change in CaCO3 statoliths of Mysidacea. In : F.R. SCHRAM & J.C. VON VAUPEL KLEIN (Eds.), Crustaceans and the Biodiversity Crisis. Brill, Leiden. Vol. 1: 859-870.
The renewal of statoliths at moulting was studied under experimental conditions in Diamysis sp., a brackish water mysid with vaterite (metastable crystalline CaCO3 ) statoliths. A carbonic anhydrase inhibitor (acetazolamide) or a generically toxic substance (ethanol) were tested by solution in ambient water. Mainly at concentrations of 6-12 mg/1 or 5.5-6.0 gfl, respectively, these substances gave rise to similar abnormalities (rarely observed in controls), such as: anomalous arrangement of the organic matrix; aberrant core formation; anomalous location of mineral precipitation; or abnormal statolith morphology. Observations on the early stage of statolith morphogenesis indicated that sensory setae are involved in the process of matrix formation or aggregation. Crystalline aggregates formed in the statocysts of a few animals treated with alcohol were found, by X-ray diffraction analysis, to consist of calcite, the most stable CaCO3 polymorph. Calcite mysid statoliths were previously known only from Miocene Paratethyan deposits, and supposed to derive from primarily vateritic statoliths by spontaneous phase transformation during or after fossilization. The precipitation of calcite instead of vaterite in living animals may be correlated to failure or damage of the organic frame which mediates the mineralization process.
statoliths; mineral composition; mineral precipitation; effect of toxicant; ethanol
Diamysis sp.