[Compared effects of heavy metal ions (Cr+IV and Pb2+) on the respiratory intensity of 2 Crustacea Decapoda Brachyoura: Macropodia rostrata and Pachygrapsus marmoratus].

The effects on the crab's respiration of the sublethal metallic concentrations are analysed upon in toto organic structures and upon their very sensitive organs in the best and stressing conditions of temperature and of salinity. There is a connection between the metallic concentrations causing respiration deteriorations and the bearable metallic concentrations (starting lethal thresholds). In the same way there is a good correlation between the level of bioaccumulation and the metabolic depletion of the tissues. It's well proved by this research that a lethal metallic concentration in the best conditions of temperature and of salinity can greatly reduce the ability of the population to survive in the natural conditions of thermic and salin stress.