Polyaromatic compounds are the major, widespread contaminants in
the aquatic environment. However, the adverse impacts of these compounds
on blood pathophysiology (hematological profiling and serum biochemical
responses) are poorly understood. As a consequence, this study was
intended to evaluate the toxic effects of naphthalene, one of the
polycyclic aromatic hydrocarbons, on the blood pathophysiology of Anabas testudineus using multiple end-point biomarker
approach. A. testudineus was exposed
to short-term (1 and 5 d) and long-term (10, 15, and 21 d) naphthalene
concentrations, that is, T1 (0.71 mg/L indicates 25% of LC50) and T2 (1.42 mg/L indicates 50% of LC50 value). The
results disclosed significant decrease in red blood cells, hemoglobin
(Hb), packed cell volume, and platelet levels, while other blood parameters,
namely, white blood cells, percent lymphocyte, mean cell volume, mean
corpuscular Hb, and mean corpuscular Hb concentration showed enhanced
levels under naphthalene intoxication. Results were more detrimental
under T2 concentration. Cholesterol, glucose, calcium, high-density
lipoprotein, and low-density lipoprotein levels gradually increased
throughout the different exposure periods under T1 and T2 concentrations,
while the triglyceride level gradually decreased during exposure periods.
Finally, integrated biomarker responses (IBR) analysis indicated that
serum biochemical parameters are more powerful than hematological
parameters for determining the naphthalene-induced fish health status.
Additionally, the IBR study clearly identified that long-term (>5
d) exposure was more harmful than short-term (<5 d) naphthalene
exposure. So, these responses may be derived as biomarkers for monitoring
naphthalene pollution in an aquatic ecosystem.
