Sea horse ( Hippocampus reidi) as a bio indicator of crude oil exposure
abstract
This study explored the suitability of the seahorse Hippocampus reidi (Ginsburg, 1933) for assessing
biomarkers of genotoxic effects and its use as a sentinel organism to detect the effects of acute exposure
to petroleum hydrocarbons. Fish were exposed to three concentrations of crude oil (10, 20 and 30 g/kg)
for 96 h, and the activity of phase II biotransformation enzyme glutathione S-transferase (GST) was
measured. In addition, we performed genotoxicity assays, such as comet assay, micronucleus (MN) test
and nuclear abnormalities (NA) induction, on the erythrocytes of thefi sh species. Our results revealed
that the inhibition of hepatic GST activity in H. reidiwas dependent on increasing crude oil concentra-
tions. In contrast, an increase in the damage index (DI) and MN frequency were observed with increased
crude oil concentrations. These results indicate that the alkaline comet assay and micronucleus test were
suitable and useful in the evaluation of the genotoxicity of crude oil, which could improve determina-
tions of the impact of oil spills onfish populations. In addition, H . reidi is a promising “sentinel organism”
to detect the genotoxic impact of petroleum hydrocarbons.