TOXICITY EFFECTS OF COPPER IONS CONCENTRATIONS ON CRAYFISH

Abstract

Forty-nine fingerlings crayfish were collected from Ogunmola fish Breed, Oyo. After the crayfish
had been acclimatized in the laboratory for a week, seven each were introduced into the different
concentrations of copper sulphate solution that had been prepared. A control, that contained 0.00mg/L
of copper sulphate was made. These set-ups were studied and observed at different intervals of thirty
minutes, one, two, four and twenty-four hours, two, three and four days. Chi-square statistical method
was used for the data analysis. It was observed that the rate of mortality increased with increase in
the concentration of the toxicant (copper sulphate solution). Conclusively, the environmental sample
was polluted with more than lethal concentrations of copper sulphate solution, that was why the
crayfish went into extinction. These recommendations were made: that the water bodies should not
be sprayed with algaecides, fungicides and pesticides, chemicals should not be used to kill aquatic
organisms, and that the environment should be monitored to ascertain its pollution.