Preliminary investigations on effects of polycyclic aromatic hydrocarbons on embryos of widow tetra, Gymnocorymbus ternetzi Boulenger

Abstract

Polycyclic aromatic hydrocarbons (PAHs) present in crude oil effluents, when released into aquatic ecosystem pose a major threat to fishes and humans. We investigated the harmful effects of PAHs on early embryonic and larval development of Gymnocorymbus ternetzi. Embryos when exposed to samples containing Dibenzothiophene (3 rings), Phenanthrenes (3 rings) and Pyrenes (4 rings) at varying concentrations (15–90 µg/L) exhibited defective embryonic and larval development. As PAHs targets aryl hydrocarbon receptor (AhR) pathway, cardiac deformities were persistent in embryos exposed to PAHs for >48 hrs; concentration specific defects included arrested embryonic development (36 ± 2.6%), cytoplasmic blubbing (24%), pericardial edema and cardiac looping (43 ± 4.2%) and tail bents and body curvature (19%). However, embryonic defects were reversible (>47%) when transferred to clean water immediately after