Fish Population Dynamic and Stock Assessment (2+1)

2.1.5. Biological features of population

In a population, after it ages, reproductive potentiality decreases and omission of some spawning season is also common. The age structure of a population, its growth, sexual maturity changes with regard to the availability of food. This influences the size of fish and fecundity, as the number of eggs laid by a fish change with food supply and many recruits are released in a spawning season of a fish.

The growth in length and weight and fecundity of a population always follows sigmoid curve. In the initial life cycle, all the above biological factors will increase with age but once the population reaches a maximum size, the above factors shows decline.