Accumulation of Fluoride in Etroplus Suratensis, Oreochromis Mossambicus and Anabas Testudineus Caught from the Surface Fresh Water Sources in Alappuzha Town, Kerala, India

Fluoride naturally occurring in ground water and surface water is known to be potent to cause serious dental and skeletal fluorosis in areas where water contains much more than the required amount of fluoride. Aim of this study was to relate the presence of fluoride in water with fresh water fishes of the corresponding aquatic body from which water samples were collected. Three species of fishes Etroplus suratensis (Pearl spot), Oreochromis mossambicus (Tilapia), and Anabas testudineus (Climbing perch) were analyzed for fluoride. The samples of fishes and the water samples from where fish was caught were collected from July 2012, October 2012 and January 2013 from the surface fresh water sources of Alappuzha Town. A mean fluoride (n=9) concentration of 0.051±0.01 (mean±SD), 0.042±0.02 and 0.035±0.02 were shown by the water samples collected in July, October and January respectively. Though fluoride is present in the water samples at a very low concentration, there is considerable fluoride content in the fish samples collected from the same water source. The accumulation of fluoride by fishes was found to be highly variable with respect to species and month. E. suratensis had accumulated 4.071±0.71 ppm fluoride in July, 274.29±2.54 ppm in October and 2.35±0.42 ppm in January. O. mossambicus was estimated to contain 18.14±0.95, 23.33±1.05 and 12.195±1.22 ppm fluoride in July, Oct and Jan respectively. No fluoride was detected in A. testudineus samples collected in October, whereas it accumulated 6.695±0.43 and 28.18±2.01 ppm fluoride in July and January respectively.