GROWTH AND MORTALITY ESTAMATION PARAMETERS FOR THE PRUSIAN CARP (Carassius gibelio, Bloch, 1782) POPULATION FROM DANUBE RIVER (Km 170 - 196)
Daniela Cristina (Ibănescu) Gheorghe, Aurelia Nica, V. Cristea, G.P. Răzlog
Abstract
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 * Lt2.866.
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.
