Physiological Changes in Nickel-exposed Nile Tilapia Oreochromis niloticus during Exposure and Recovery Periods
K. U., Sheethal
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
Prakash Nadoor
Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, Karnataka, India.
S. R. Somashekara
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
U. A. Suryawanshi
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
K. R. Amogha
College of Fisheries, Mangaluru, Karnataka Veterinary, Animal and Fisheries Sciences University, Bidar, India.
P. A. Telvekar
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
S. T. Shelke
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
J. G. K. Pathan *
College of Fishery Science, Nagpur Maharashtra Animal and Fisheries Sciences University, Nagpur, India.
*Author to whom correspondence should be addressed.
Abstract
Heavy metals are a significant problem in aquatic ecosystems as they are toxic and tend to accumulate, immediately affecting fish physiology. The present investigation was carried out to evaluate the sub-lethality of Nickel chloride on fingerlings of Nile tilapia, Oreochromis niloticus on long-term exposure to it is below safe concentrations1/fifth (9.39 ppm) and 1/10th (4.69 ppm). The physiological studies revealed a significant reduction in Oxygen Consumption Rate (OCR), Ammonia-N Excretion Rate (AER), Oxygen Rate (O: R) and Food Consumption Rate (FCR) and behavioural changes during accumulation and depuration phases. Limited recovery was obtained in all the physiological parameters after depuration for 28 days from the end of the accumulation period.
Keywords: Nickel, Oreochromis niloticus, physiology, exposure, recovery, metallic contaminants