Bioaccumulation and Depuration Dynamics of Nickel Chloride in Nile Tilapia (Oreochromis niloticus) Exposed to Sub-lethal Concentrations

The current objective of this research is to examine the bioaccumulation and subsequent depuration levels of nickel chloride within vital organs such as the gills, liver, and kidney of Oreochromis niloticus under controlled laboratory conditions. The fish were subjected to exposure under two sub-lethal concentrations, i.e., 1/5th (9.39 ppm) and 1/10th (4.69 ppm), for 28 days of absorption and subsequently transferred to uncontaminated, good aerated water for 28days of elimination (depuration). Following 28 days of exposure to lower sub-lethal and higher sub-lethal nickel chloride concentrations, the sequence of bioaccumulation of nickel chloride in organs was observed as kidney > liver > gills. The depuration trend for higher and lower concentrations was gills> liver > kidney. The kidney exhibited the highest accumulation of Ni. Meanwhile, the Ni depuration in the gills was significantly (p<0.05) more when compared to other routes following exposure to both concentrations. This research assessed nickel chloride's bioaccumulation and depuration dynamics in Oreochromis niloticus, providing insights into its physiological responses to metal exposure. The study concludes that nickel accumulates predominantly in the kidney, with gills exhibiting the highest depuration rates, highlighting the importance of understanding metal uptake and elimination mechanisms in aquatic organisms for effective pollution management

Assessment of Carapace Dimensions, Condition Factor and Sex Ratio of Portunus pelagicus (Linnaeus, 1758), Along the Mangaluru Coast, Karnataka, India

The research examined the correlations between width-weight and length-width relationships in Portunus pelagicus along the Mangaluru coast in Karnataka, India. A total of 607 specimens were collected fortnightly from the Mangaluru fish landing centre from January to December 2022, of which 327 were males and 280 were females. The relationship between weight and carapace width for both sexes was determined as y = 2.8661x - 1.0413, with an R-squared value of 0.7252. Conversely, the relationship between carapace length and weight for both sexes yielded the equation y = 2.9571x - 0.1628, with an R-squared value of 0.7449.  By using the Chi-square analyses, the male and female ratio was compared. The sex ratio of P. pelagicus was found to be 1:0.88 (Male: Female), showing no significant deviation from the anticipated ratio of 1:1. The condition factor varied between 0.9933 to 1.0427 for males and 1.0047 to 1.0658 for females, exhibiting a range in physiological status across the sexes