TRACER STUDIES ON CALCIUM AND STRONTIUM MINERALIZATION AND MINERAL CYCLING IN TWO SPECIES OF FORAMINIFERA, ROSALINA LEEI AND SPIROLOCULINA HYALINA1
- 1 March 1970
- journal article
- Published by Wiley in Limnology and Oceanography
- Vol. 15 (2) , 173-182
- https://doi.org/10.4319/lo.1970.15.2.0173
Abstract
Mineral cycling in the calcareous foraminifera Rosalina leei and Spiroloculina hyalina was traced with 45Ca and 90Sr. Incorporation of these radionuclides as well as 35S and 32P was proportional to growth when they were introduced into the system in the range of 1 × 104– 1 × 105 dpm/ml of medium (90Sr specific activity ∼ 109 µCi/g; 45Ca specific activity 160 µCi/g; 35S specific activity 95 µCi/g; 32P specific activity 2.03 mCi/g). Although 14C was a good indicator of growth during the first 3 weeks, its usefulness declined as the cultures aged. Some 45Ca and 90Sr was adsorbed to dead tests. Both foraminifera were decalcified by treatment with 0.01% Na2EDTA in seawater at pH 8.1. Recalcification and growth took place when individuals were returned to control media. Ten to 0.1 µm 2‐acetylamino‐1,3,4‐thiadiazole‐5‐sulfonamide (Diamox) inhibited Ca but not Sr incorporation into the test. Calcium and strontium were lightly bound to foraminiferan shells and under conditions of alkaline pH and low hydrostatic pressure these did not exchange with environmental ions.This publication has 0 references indexed in Scilit: