Crab zoeae (Rhithropanopeus harrisii) were exposed during their development opment to a range of free cupric ion activities regulated in seawater by use of a copper chelate buffer system. Most cytosolic copper was found to be associated with metallothionein. Copper-thionein could be related to free cupric ion activity, and a shift in copper-thionein accumulation was correlated with inhibition of larval growth. These data reveal predictable relations between cupric ion activity in seawater and processes at the cellular and organismic levels.

No abstract

No abstract

We have examined the relationships between Cd ion activity [Cd2+], in seawater, Cd accumulation and subcellular distribution and growth in the polychaete Neanthes arenaceodentata. Organisms were exposed for 3 weeks to a range of [Cd2+] in a Cd-chelate buffer system. Cadmium accumulation and growth were monitored weekly for each exposure group and subcellular Cd distributions were determined at the end of the 3-week period. We found Cd associated with all of the subcellular fractions except the very low molecular weight ligands. Total Cd accumulation was greatest at day 7 and decreased over time in all but the highest [Cd2+] where it remained constant. For each point in time, however, there was a linear relationship between total Cd and [Cd2+] in seawater. Linear relationships were also observed between [Cd2+] and Cd loading in each subcellular ligand pool. Specific growth rates varied with both [Cd2+] and time in a nonlinear manner.

Crab larvae (Rhithropanopeus harrisiiere exposed to a range of free cupric ion concentrations, [Cu], regulated in sea water by a metal chelate buffer system. We found a biphasic relationship between intracellular copper distribution and [Cu] in sea water. At [Cu] within the ambient range (10 to 10 M), cytosolic copper was associated with both metallothionein (MT) and high molecular weight (HMW) ligands, and was independent of external [Cu]. At higher [Cu], copper was also associated with very low molecular weight (VLMW) ligands, and accumulated in this ligand pool and the MT pool as external [Cu] increased. In marked contrast, copper in the HMW ligand pool did not correlate with [Cu] in sea water over the entire range of exposures. Reductions in larval growth occurred at greater than estimated ambient [Cu] and correlated with copper accumulation in the MT and VLMW pools.