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, fis h 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 b etween the sexes is also registered. Males are heavier and longer (+ 3 57 g or + 17.0 % and + 6.2 % in length at day 120) and present a highe r 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.