GROWTH AND MORTALITY ESTAMATION PARAMETERS FOR THE PRUSIAN CARP(Carassius gibelio, Bloch, 1782) POPULATION FROM DANUBE RIVER (Km 170 - 196)

摘要

This paper presents the results of the growth and mortality parameters of the Prussian carp population from the Danube (km 170-196). This study was performed on 314 specimens of Prussian carp caught in the period 2006-2009 in the both river and the floodplain ponds. The purpose of this study was to determine the relationships: length – weight (L - W), to estimate the growth parameters (von Bertalanffy) L∞, k, t and the mortality rates (Z, M, F) for the Prussian carp population. The relationship between length – weight (L – W) in the study period for Prussian carp population is W=0.0298 * Lt^2.866.The assessment of the growth parameters (von Bertalanffy) L∞, k, to, led to values comparable to other populations of Prussian carp in our country which live in similar conditions.The growth equation that shows the body length (Lt) as a function of the age (t) from the studied population has the form: Lt=39.38*(1-e^{-0.630(t+0.140)}).The estimated values of the mortality rates for the studied population are high thus: total mortality (Z) is 2.29 and the natural (M) reaches 0.825.Exploitation rate, E = 0.63 calculated for the carp population exceeds the optimum value (0.5) suggesting that the population of carp in the studied area is over fished.