Assessment of Micronucleation and Abnormal Nucleation in the Peripheral Erythrocytes of the Fish Mystus gulio of Hooghly River Downstream as per Seasonal Variation

Abstract

The aim of the study was to identify the frequencies of micro nucleations (MN) and nuclear abnormalities (NAs) in the peripheral erythrocytes of fish (Mystus gulio Ham. – Buch.) inhabiting downstream at three locations of river Hooghly, West Bengal, India. The study area mainly consists of three sampling sites, viz., Budge Budge (Bg), Batanagar (Bt) and Birlapur (Br), which were selected. The present study is a first-time endeavour to know the environmental status with particular reference to water pollution through genetic biomonitoring in the Hooghly River of a middle stretch from Batanagar to Birlapur near Diamond-Harbour coastal zone in the inhabiting fish (M. julio). The genotoxic effect, especially induction of MN and NAs in the peripheral erythrocytes, was done on the studied fish. In the case of MN frequencies (%), the values for sites Bt1 & Bt2, Bg1 & Bg2 and Br1 & Br2 were observed 1.92±0.10, 1.40±0.24 and 2.00±0.13, respectively were increased during pre-monsoon season compared to post-monsoon season (1.83 ±0.15, 1.36 ±0.04 and 1.91 ±0.12, respectively). The frequencies (%) of NA, such as lobed nuclei (LN), blebbed nuclei (BLN), notch nuclei (NN), bi-nuclei (BN), dumble-shaped nuclei (DSN), retracted nuclei (RN), nuclear caryolysis (NC), and fragmented nuclei (FN) values, were also observed in the fishes of three study sites. In the case of NA frequencies (%), the values for sites Bt1&Bt2, Bg1&Bg2 and Br1&Br2 were observed higher for BLN (1.54±0.09, 1.14±0.07 and 1.77±0.10, respectively), BN (1.09±0.04, 0.85±0.21 and 1.32±0.06, respectively), NN (1.02±0.09, 0.61±0.16 and 1.18±0.06, respectively), LN (1.86±0.08, 1.22±0.07 and 2.12±0.11, respectively), DSN (2.22±0.22, 1.69±0.08 and 2.56±0.11, respectively), RN (2.33±0.15, 1.82±0.13 and 2.73±0.05, respectively), FN (2.20±0.10, 1.72±0.08 and 2.56±0.13, respectively) and NC (3.01±0.06, 2.72±0.11 and 3.32±0.08, respectively) during pre-monsoon season when compared to post-monsoon season (BLN = 1.50 ±0.07, 1.06 ±0.03 and 1.73 ±0.07; BN = 0.83 ±0.11, 0.62 ±0.11 and 1.18 ±0.06; NN = 0.77 ±0.15, 0.43 ±0.11 and 1.05 ±0.03; LN = 1.42 ±0.06, 1.14 ±0.06 and 2.06 ±0.08; DSN = 1.76 ±0.06, 1.34 ±0.05 and 2.36±0.08; RN = 1.68 ±0.08, 1.30 ±0.06 and 2.31 ±0.08; FN = 1.59 ±0.08, 1.18 ±0.04 and 2.46±0.11 and NC = 2.58 ±0.53, 2.37 ±0.43 and 3.18 ±0.09, respectively). This study provides an important impact of mutagenic risk on the fish specimen, which may vanish due to the long-term effect of genotoxins or a combination of other pollutants. This specimen may show an alarming impact of water pollution, and this study is suggested for future study with other fish species to know the risk of vulnerability of mutation.