Gagneten A M, Imhof A
Department de Ciencias Naturales, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe, Argentina.
J Environ Biol. 2009 May;30(3):345-8.
The freshwater crab, Zilchiopsis collastinensis was exposed in vivo to determine Cr accumulation in visceral content. After an acclimation period we added Cr(K2Cr2O7) at nominal concentrations of 2 mg l(-1) Cr(VI) and 5 mg l(-1) Cr(VI) and a control (T0) under the same conditions, without Cr. At days 1, 7 and 14, Cr was measured in water sediments and crabs and the bioconcentration factor (BCF) in relation to water and to sediment were obtained. Considering all samples and all the study period, crabs registered 3 times more Cr than sediments and 18 times more Cr than water. Cr levels in Z. collastinensis tissues were always lower in the control than in T1 and T2; no significant differences among days 1, 7 and 14 were found in the control. In the treatments, no significant increase in Cr levels in tissues were found between days 1 and 7, neither between days 7 and 14 in both concentrations tested. Significant differences were found between the control and T1 and T2 (p<0.001), but not between T1 and T2. The highest BCF obtained for Z. collastinensis were 51.82 and 51.42 in T1 and T2 in water at 14 days of exposure. This study shows the efficiency of freshwater crabs to accumulate Cr from water.
为确定内脏中铬（Cr）的积累情况，对淡水蟹Zilchiopsis collastinensis进行了活体暴露实验。在适应期后，我们在相同条件下分别添加标称浓度为2 mg l(-1) Cr(VI)和5 mg l(-1) Cr(VI)的Cr（重铬酸钾）以及一个无Cr的对照组（T0）。在第1天、第7天和第14天，对水、沉积物和蟹体内的Cr进行测量，并获得了相对于水和沉积物的生物浓缩系数（BCF）。考虑所有样本和整个研究期，蟹体内的Cr含量比沉积物高3倍，比水高18倍。在对照组中，Z. collastinensis组织中的Cr水平始终低于T1和T2组；在对照组中，第1天、第7天和第14天之间未发现显著差异。在处理组中，在所测试的两种浓度下，第1天和第7天之间以及第7天和第14天之间，组织中的Cr水平均未发现显著增加。对照组与T1和T2组之间存在显著差异（p<0.001），但T1和T2组之间无显著差异。在暴露14天时，T1和T2组中Z. collastinensis在水中获得的最高BCF分别为51.82和51.42。本研究表明淡水蟹从水中积累Cr的效率。
