Histopathological biomarkers in juvenile silver catfish (Rhamdia quelen) exposed to a sublethal lead concentration

The aim of this study was to determine the 96-h lethal concentration (96-h LC50) of lead (Pb) in silver catfish, Rhamdia quelen, and to determine histopathological biomarkers in fish exposed for 96-h to a sublethal concentration at 25% of the LC50. The 96-h LC50 was 108 mg L-1. In gills, the length and thickness of lamella and thickness of the filament epithelium were significantly higher in fish exposed to Pb for 48-h than in control fish whereas the interlamellar distance decreased. In the liver, the area occupied by lipid droplets and size of hepatocytes showed significantly higher values after 24-h of exposure. The percentage of abnormal renal tubules was higher in fish exposed to Pb, exhibiting a timedependent increase. These variations in histopathological biomarkers permit the definition of the overall response of R. quelen to Pb and the potential usefulness in the monitoring of Pb contamination. (C) 2014 Elsevier Inc. All rights reserved.