The red swamp crayfish P. clarkii has been recently introduced to the Egyptian freshwater system and became widely distributed all over the country. Respiration has been used in the present study to see the differences, if there is any, in
respiration of P.clarkii in the new habitats compared with that obtained from its native habitats and to evaluate it's possible use as a bio-indicator for total water quality including copper and cadmium heavy metals.
The present study revealed that, the oxygen consumption of P. clarkii under controlled conditions lies within the range of that obtained from other studies. The amount of consumed oxygen was dependent on the degree of water quality and the
ambient concentrations of copper and cadmium. Increasing sublethal concentrations of copper and cadmium increased the amount of oxygen consumed by P. clarkii. The results indicate that P.clarkii may be suitable as a bioindicator for total
water quality as well as copper and cadmium toxicity.