Studies on the Growth and Population Dynamics of Rita rita from River Ganga at Allahabad (India)

摘要

Age and growth are two attributes of prime importance in assessing fish population. The age structure, like other parameters of the population may alter in response to environmental fluctuation. The proportion of different ages and sexes gives the population a definite structure. Ratio of young animals to adult often indicate whether a population is expanding, contracting or is stabilized. The age pyramid for R. rita fits into the category of broad base pyramid because pre-reproductive age groups (0+, 1+) constituted 58.1% indicates an expanding population and hence was not stable, like an ideal population. High ratio of immature to adult is characteristic when populations are recovering from catastrophe. The catastrophics may be environmental as well as anthropogenic. The data on age structure can also be used to draw inferences on health of the population, mortality and survival rate.