Crayfish utilize aquatic plants as a food source and may concentrate pollutants, such as heavy metals. Monitoring the possible heavy metal presence in crayfish edible tissues is therefore important since crayfish can be part of the human diet. In this study we have analysed specimens of Cherax destructor of two different sizes coming from a crayfish farm, with respect to heavy metal (lead, copper, cadmium, chromium, zinc) concentrations in the muscle, hepatopancreas and exoskeleton. Furthermore, the metal concentrations were determined in water, sediment and in plants.Our data show that the contents of lead, copper, cadmium, chromium and zinc, are higher in the tissues with respect to water, indicating in some cases their bioaccumulation in Cherax destructor. The content of lead and zinc in sediment and plants the animals feed on, was higher than in tissues and organs, suggesting that biomagnification does not occur for these heavy metals. Copper and chromium show biomagnification in all tissues, while cadmium only in the hepatopancreas.
Key-words:Cherax destructor, heavy metals, bioaccumulation, biomagnification.
DĂTERMINATION DE MĂTAUX LOURDS DANS L'ĂCREVISSE CHERAX DESTRUCTOR EN ĂLEVAGE
RĂSUMĂLes Ă©crevisses s'aliment de plantes aquatiques. En consĂ©quence, ils peuvent accumuler des substances polluantes comme les mĂ©taux lourds. Analyser la prĂ©sence Ă©ventuelle de mĂ©taux lourds dans la part comestible des Ă©crevisses est donc important, car ils sont utilisĂ©s pour l'alimentation humaine. Dans ce travail nous avons Ă©valuĂ© la prĂ©sence de mĂ©taux lourds (plomb, cuivre, cadmium, chrome et zinc) dans le muscle, dans l'hĂ©patopancrĂ©as et dans l'exosquelette de l'espĂšce d'Ă©levage Cherax destructor. Les organismes Ă©tudiĂ©s ont Ă©tĂ© rĂ©partis en deux groupes sur la base de leur taille. De plus, nous avons Ă©valuĂ© la prĂ©sence de mĂ©taux lourds dans l'eau, dans le sĂ©diment et dans la vĂ©gĂ©tation aquatique. Nos donnĂ©es montrent que la concentration en plomb,