The effect of initial larval stocking density on growth and survival in common barbel Barbus barbus (L.)

Abstract

Summary Aim of the study was to determine the effect of initial larval density on growth and survival of the common barbel Barbus barbus (L.) under controlled conditions. The experiment examined fish density from 20 to 200 ind. L−1 during intensive rearing at 25°C. Rearing lasted 21 days whereby the average total fish length, weight and survival were recorded. During the entire period fish were fed live nauplii Artemia sp. The data provided the basis for calculating the specific growth rate (SGR), Fulton’s condition index (K), and analysis of the relationship between biomass and the stocking density. The documentation was also used to determine the level of ontogeny. The study data obtained indicated that initial larval density has no effect on survival (over 98% in each treatment), level of ontogeny, or on the rearing indexes. Fish achieved the juvenile stage during the second week of rearing ( 0.05). The findings of this study suggest that stocking density in common barbel larvae is not a factor limiting growth or the ontogenetic development rate during initial rearing. This creates considerable potential for improvement in stocking material production under controlled conditions and should have a positive effect on the economic effectiveness of production.