Effects of temperature on the acute toxicity of heavy metals (Cr, Cd, and Hg) to the freshwater crayfish, Procambarus clarkii (Girard).

TLDR: Evaluating the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures finds chromium, an essential trace element for humans and animals, is involved in normal carbohydrate metabolism.

Abstract: Chromium, an essential trace element for humans and animals is involved in normal carbohydrate metabolism; however, it is toxic at high concentrations. There is no evidence that cadmium and mercury are biologically essential but their toxicity for organisms is well known. Both cause toxic effects at low concentrations to most organisms, especially in combination with other environmental variables such as temperature. Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and waste waters in this area. In 1978, the American red crayfish Procambarus clarkii appeared in lake Albufera and in the surrounding rice fields. Without adequate sanitary control, the crayfish is presently being fished commercially for human consumption. The purpose of the present study is to evaluate the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures.