laccase, catechol oxidase, and ascorbic acid oxidase), a component 

 of hemocyanin, hepatocuprein and the hemocup rein-protein complexes 

 found in liver tissue, to name a few. Relatively high levels of 

 copper are regularly assimilated by animals and the Department of 

 Health, Education and Welfare, Food and Drug Administration have not 

 found it necessary to set a maximum limit for copper in foods (A. A. 

 Russell, Bureau of Foods, personal communication). When ingested or 

 absorbed in the ionic form, however, copper becomes toxic and its 

 reaction with biological systems is generally attributed to damage 

 to cellular membranes due to complexing of the copper with lipid 

 factions of the cell wall and subsequent interference with ion trans- 

 port (Zeitoun et at 1969). 



Because of the physiological ability to metabolize ingested, organ- 

 ically complexed copper it can be expected that copper will not show 

 appreciable biological magnification in the predator-prey relation- 

 ships. The work of Hueck and Adema (1968) on the role of copper 

 toxicity in the predator-prey relationship of Daphnia and algae, 

 although preliminary in nature, tends to confirm this hypothesis. 



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