Statistical method of estimating the size at first maturity in fishes

The reproductive process in all animals commences once they attain maturity at a particular size, which depends upon environmental and ecological factors and the biological features of the animal. The size at maturity is subject to variation between species and within species. Thus all fishes of the same cohort or size need not attain maturity at some fixed age or length. At present, methods are available to estimate the exact average size of fish at first maturity by graphing the percentage cumulative frequency curve of mature fishes against size, or by plotting the mean condition factor against size. These methods give a single estimate of the mean size at first maturity in the population. Statistically this estimate may be without any confidence limits. A method of obtaining such lilmits is explained in the present paper.