Effects of different rearing technologies on production traits, water and sediment quality in European catfish (Silurus glanis) farming

Abstract

Aim of the study was to investigate the effect of two different rearing technologies (monoculture (M), intensive-extensive pond system (I-E)) on the production traits, water and sediment quality in case of European catfish. During a 153 days long trial two years old European catfish (mean individual weight of 485.7±3.4 g) and common carp (mean individual weight of 348.9±2.5 g) were stocked into the experimental system. Final mean weight of the fish were as follows: 1932.9±194.5 g (European catfish) and 2266.9±87.56 g (common carp). No significant differences were observed in the production traits. Specific growth rate (SGR) was lower (0.9±0.1 %/day) than expected. Significant differences were found in nitrate-N, nitrite-N, orthophosphate and total suspended solids content. Significant decrease was observed in the Kjeldahl-N and phosphate content of sediment in the extensive-intensive combined system. These results suggest that transformation of the nutrients in the combined system exceeds that of monoculture; significant amount of organic N and P compounds were removed and accumulated in the additional common carp yield.