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In this study, we analysed Pb2+ effects upon planarian Dugesia japonica, based on the assessment of acute toxicity, feeding behavior and locomotory velocity. The results showed that the 24, 48, 72 and 96 h LC50 of Pb2+ for D. japonica were 110.52, 64.26, 28.00 and 13.80 mg Pb2+/L, respectively. Planarian locomotory velocity was significantly reduced from 0.5 mg Pb2+/L onward. Feeding behavior was significantly affected by Pb2+, and a dose-response relationship was observed. In this study, the results suggested that feeding behavior and mobility in the aquatic planarian D. japonica could be used as biomarkers for Pb2+ exposure in a freshwater environment. [ABSTRACT FROM AUTHOR]

Planarian worm, a favored animal model in developmental biology, is being recognized as an animal model in toxicological research. This study was conducted to investigate the acute toxicity, mobility and regeneration performance of chlorpyrifos toward planarians. The 24, 48, 72 and 96-h LC50 values were calculated to be 0.540, 0.428, 0.221 and 0.175 mg L-1 , respectively. In planarians exposed to sub-lethal doses of chlorpyrifos, the stimulatory or hormetic effect at low concentrations, followed by a concentration-response relationship, was observed for locomotor activity. The regeneration IC50 values for eyespots and auricles were 0.056 and 0.054 mg L-1 for exposure times of 6 days, respectively. [ABSTRACT FROM AUTHOR]

Acute toxicity tests of a freshwater Planarian (Dugesia japonica Ichikawa et Kawakatsu) exposed to cadmium were conducted according to the American Society for Testing and Materials (ASTM) guidelines. The 24, 48, 72 and 96-h LC50 values were calculated as 4.92, 2.25, 1.52 and 1.45 mg Cd2+/L, respectively. When compared with different phyla or classes of freshwater animals, the rank of Dugesia japonica in species sensitivity was in the 43-44 and 39-40 ranges for 24- and 48-h LC50, respectively. D. japonica had moderate sensitivity. A mobility assay was carried out to explore the behavioral effects of Cd2 on D. japonica. At sub-toxic concentrations, Cd2 decreased D. japonica locomotor behavior in a concentration-dependent manner. The mobility IC50 for adult D. japonica at 24, 48, 72 and 96 h were calculated to be 3.07, 2.66, 1.35 and 1.37 mg Cd2 IL for measured concentrations, respectively. Locomotion of newborns was seriously impaired and cannot be used to calculate the mIC50. Results showed that D. japonica can be regarded as a useful bioindicator species for the detection and evaluation of Cd2 effects upon freshwater invertebrates. Acute toxicity on D. japonica and mobility assay for adult D. japonica can be used as biomarkers for Cd2 exposure in a freshwater environment. [ABSTRACT FROM AUTHOR]