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Title: Studies on the effects of heavy metals on freshwater crustacea
Author: Al-Ghamdi, H. S. H. H.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1986
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The effects of cadmium and zinc ions upon the longevity of two freshwater crustaceans, Daphnia pulex (de Geer) and Cyclops fuscus (Jurine) were examined at temperatures (8°C, 14°C, and 21°C). Winter collected speciments of both species were found to be more resistant than summer collected specimens. In both species Cd^++ was more resistant than Zn^++ and resistance to both metal ions was greater in C.fuscus than in D.pulex. Temperature has a synergistic effect on the toxicity of both metals to both species. The pH influence on the toxicity of Cd^++ and Zn^++ to D.pulex was examined. The toxicity of both metals increased with increasing acidity. Acidity alone was lethal to D.pulex with no Cd^++ or Zn^++ added. Cadmium and zinc were accumulated by D.pulex to high concentrations in proportion to time and concentration in solutions. Cadmium accumulations were lower than zinc. The major sites of accumulation, tested using Zn^65 were the gut, hepatopancreas and exoskeleton of D.pulex. The respiratory rate of D.pulex and C.fuscus were affected by the presence of CD^++ and Zn^++, but D.pulex was more affected than C.fuscus, and cadmium effect was generally more than zinc ions. The ultrastructural changes in the hepatopancreas of D.pulex were examined after exposure to cadmium ions. The hepatopancreatic cell was affected. Mitochondria were the most affected organelles.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available