Haemolymph transport and tissue accumulation of exogenous copper in the shore crab, Carcinus maenas

Exogenous (i.e. non-haemocyanic) copper was quantified in the haemolymph of shore crabs Carcinus maenas and the fate of the metal was studied in animals contaminated either by exposure to waterborne copper or by injection into the haemolymph space. Direct contamination from the ambient water resulted in a relatively steady level of haemolymph exogenous copper by 2–3 days. Following a single injection, exogenous copper disappeared rapidly from haemolymph, following an exponential time course (half time 22.4 h). Insignificant amounts of the metal were excreted to the ambient water but dose-dependent tissue uptake could be demonstrated in vivo and by using an in vitro hepatopancreatic cell preparation. Almost all haemolymph exogenous copper was protein-bound and non-filterable. By ultracentrifugation and gel filtration experiments, the only protein binding exogenous copper was shown to be the respiratory pigment haemocyanin. These results emphasize the role of haemolymph and haemocyanin as an efficient copper transport system in the crustaceans