Free cupric ion activity in seawater: effects on metallothionein and growth in crab larvae.

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.