Accumulation of Co by Bivalve Tridacna crocea

Abstract

In order to clarify the reason for the high accumulation of 60Co by Tridacna sp. in the field survey, a radioisotope tracer experiment was performed on Tridacna crocea. The radioactivity of 60Co in the kidney was 64.7%, and that in the liver was 1.7%, of the total radioactivity of 60Co in the soft parts. The radioactivity of 60Co (cpm/g) in the margin of the mantle with symbiotic zooxanthellae was comparable to that in other parts of the mantle. The concentration factor and effective half life of 60Co in the kidney were estimated to be 58000 and 770 days, respectively. On the gel filtration profile, 60Co combined with one constituent in the kidney; this constituent was supposed to be a protein, from its optical density at 280 nm and the results of its electrophoresis. The molecular weight of this constituent was estimated to be around 3000. The constituent in the kidney migrated 15 cm in 3.5 hours under 90 mA and 200 V. The amounts of glycine, aspartic acid, and glutamic acid were dominant and were different from those in the branchial heart of Octopus vulgaris. © 1982, The Japanese Society of Fisheries Science. All rights reserved.