23. Differential bioaccumulation of metals in the ampullariid snail Pomacea canaliculata and its midgut gland endocytobiont

ARRIBÉRE M, VEGA IA, CARRIÓN AM, CASTRO-VAZQUEZ

Uspallata, Mendoza

Congreso; XXIII Reunión Anual de la Sociedad de Biología de Cuyo; 2005

Sociedad de Biología de Cuyo

Two morphs of a bacterial endocytobiont (identified as C and K corpuscles) are found within cells of the midgut gland in P. canaliculata. Since previous evidence suggested that the K morph was able to accumulate iron, preliminary observations were launched to measure toxic metals concentrations in both isolated morphs, as well as in samples of the midgut gland, the posterior kidney and the foot of cultured snails. Neutron activation technology was used to determine metals. We were surprised by the ability of both the C and the K morphs to accumulate uranium (in concentrations about 300 and 80 times that of aquarium water, respectively). Uranium levels were also found in the midgut gland (which includes the endocytobiont), and were much lower in the posterior kidney and foot of laboratory cultured snails. Mercury accumulation also occurred in the endocytobionts (about 100 and 90 times above aquarium water, for C and K morphs, respectively) but it was also significantly accumulated in the midgut gland and the posterior kidney (about 75 and 100 times above aquarium water, respectively). Arsenic was also accumulated, and predominated in both C corpuscles and the midgut gland (near 180 times above aquarium water). These preliminary observations indicate that this freshwater snail and its endocytobiont may be used as a bioindicators of metal pollution in limnic environments