The effect of cadmium exposure on the cytoskeleton and morphology of the gill chloride cells in juvenile mosquito fish (Gambusia affinis)

Abstract

One of the wide spread aquatic organisms in the rivers of Indonesia is the mosquito fish (Gambusia affinis (Baird and Girard, 1853)). Mosquito fish are invasive species that can adapt to environmental changes, also they act as bioindicator species for polluted environments. The study aims to determine the effects of the exposure to cadmium on the cytoskeleton and morphology of the gill’s Chloride Cells (CCs) in the mosquito fish. In cadmium treated mosquito fish (0.03 mg/L for 28 days), the immuno-fluorescent light microscope showed strong absorption of actin stain and strong primary MT antibody uptake in CC and apical epithelia. Scanning electron microscopy observations showed a change in microfilament organized at the CC's apex, with the appearance of some actin filament aggregates. Higher cadmium concentrations (0.03 and 0.015 mg/L) did not alter such reorganization. Microtubules weren’t significantly affected by similar exposures. SEM analysis showed that cadmium exposure induced a significant increase in CC's surface area. After 28 days, the density of CC also increased. It was observed that there is an increase of CC's surface area, although the CC density didn’t increase significantly. The results of this study confirmed the cytotoxic effects of cadmium on mosquito fish.