Acute and subchronic effects of petroleum on the freshwater fish Hoplias aff. malabaricus

Abstract

Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hoplias aff. malabaricus. The effects of WSF were evaluated at a molecular level using the comet assay and micronucleus test for genome damage; and at a morphological level through histological identification of liver pathologic lesions. In both acute and subchronic exposure we found low levels of DNA damage (< 10% of comet tail) and non-significant frequency of micronucleus in WSF exposed fish. The most significant liver lesions in WSF exposed fish were fatty vacuolization, hypertrophy and focal necrosis. Since these tissue injuries were progressive and persistent, their irreversibility may negatively affect fish recruitment, even in a such resistant top predator.

Evaluation of Mitigation Role of L-Phenylalanine-Based Low-Molecular-Weight Gelator against Oil Pollution-Induced Nile Tilapia Toxicity

“…Using an Olympus epifluorescent microscope, smears were then stained with 0.01 percent Giemsa dye, and 2000 cells/fish were counted. For every 1000 cells, the number of micronuclei (MN) was counted [69] Total RNA was extracted from treated fish liver tissues using the usual TRIzol ® Reagent extraction procedure (Invitrogen GmbH, Darmstadt, Germany). Before usage, RNA was hydrolyzed in diethylpyrocarbonate (DEPC) water [48].…”