Study of age and growth of Ganga river system at Allahabad

Ageing biology of Labeo calbasu of correlation was observed between total length and scale radii of fish which shows significance of study. Formation of growth ring was annual in nature. The first annulus was formed at a found decreasing with age. Phenomenon of growth compensation was observed in the age class eight. The spawning as the prime factor with low feeding intensity were the factors causing annulus formation. Fishes under examination belonged to 0 to 8 age classes. The maximum specimens were recorded for age class 2. It appeared that fishes of age class 1 and 2 were more vulnerable to the fishing gear. The mean back calculated length (in cm) obtained by the analysis of pooled key scale samples were 16.49, 25.65, 35.32, 43.09, 48.11, 51.36, 56.57, 69. 15 for the classes respectively. The growth rate (length increment in cm) was recorded 16.49, 9.16, 9.67, 7.77, 5.02, 3.25, 5.21 and 12.58 for 1 st to 8 th age classes respectively Growth compensation was observed in age class eight. Specific rate of linear growth (C 37.49, 21.99, 11.65, 6.75, 10.19 and 22.24 between different classes seventh and eighth. The index of species average size ( importance of the fish. The maximum attainable size was re year of life (at a size of 32.0cm and 34.0 after completion of third year of life at a length of 37.2