acute and chronic toxicities assessment of arsenic (iii) to catfish, silurus lanzhouensis in china

We evaluated the lethality, uptake, depuration, accumulation, and effects of waterborne arsenic in Lanzhou catfish (Silurus lanzhouensis). The 96-h LC50 and safe concentrations (SC) for Lanzhou catfish were 12.88 and 1.288 mg/L, respectively. We evaluated the effects of chronic exposure to 0 mg/L (C), 1.288 mg/L (T1), 0.5 mg/L (T2), and 0.1 mg/L (T3) and measured depuration rates post-exposure. As accumulated in the target organs in the following order of concentration: gill > muscle > brain > liver, which is consistent with the variation in k1. The values for k1 and CAmax declined with a decrease in arsenic concentration in the different target organs, whereas the reverse was true for BCF. The CL,50(t) values decreased initially and then approached equilibrium status after 30 of exposure. The gill tissue had the highest depuration rates, followed by muscle, brain, and liver. The treatment groups exposed to lower arsenic concentrations treats had lower k2 values in the target organs, but higher depuration half-lives (t1/2) at lower arsenic concentrations. Our results demonstrate that the target organs of Lanzhou catfish are capable of regulating arsenic toxicity by way of internal regulation mechanisms, and the rate of arsenic uptake and depuration over time are concentration- and tissue-dependent.