Different growth and processing traits in males and females of European catfish, Silurus glanis

Two experiments were developed in France to assess whether growth and processing traits differ for males and females in the European catfish, Silurus glanis. In the first experiment, fish were raised from 5 to 200 g in a pond for 7 months. A significant sex effect is demonstrated in males for live weight at the end of the experiment (males 147.5 +/- 5.4 g vs females 132.9 +/- 4.9 g) and head index (males 20.6 +/- 0.1 % vs females 21.2 +/- 0.1 %, P < 0.05). In the second experiment, fish were raised from 885 +/- 196 g to 2 266 +/- 418 g in a recirculated system at 20.7 +/- 1.4 degrees C for 120 days. A differential growth between the sexes is also registered. Males are heavier and longer (+ 357 g or + 17.0 % and + 6.2 % in length at day 120) and present a higher gutted weight and yield (+ 367 g or + 18.7 %; 95.0 +/- 0.9 % vs 93.8 +/- 1.8 %) and fillet weight (+ 233 g or + 20.9 %) than females after slaughter. (C) Ifremer/Elsevier, Paris.