Artificial spawning of European catfish Silurus glanis L.: differences between propagation results after stimulation of ovulation with carp pituitaryand Ovopel

The effect of spawning on European catfish females with an average body wei ght of 5.6 kg and 11.2 kg was investigated, with carp pituitary and Ovopel being used as ovulation stimulators. Ovopel induced ovulation in a higher p ercentage of females of both smaller and larger body weight. The applied ov ulation stimulators did not significantly affect the weight of the obtained eggs. On the other hand, the effect of the stimulators was highly signific ant (P less than or equal to 0.01) with respect to the percentage of live e mbryos after 24-, 48- and 56-h incubation. The fish of greater body weight yielded eggs of a significantly (P less than or equal to0.05) greater weigh t. although of poorer quality, The interaction between the ovulation stimul ator and female body weight was statistically significant (P less than or e qual to 0.05) for the weight of the obtained eggs and highly significant (P less than or equal to 0.01) for the percentage of live embryos after 48-h incubation. For the percentage of live embryos after 24- and 56-h incubatio n, the statistical significance (P less than or equal to 0.05) of this inte raction was determined. In the case of females of smaller body weight, a st atistically significant (P less than or equal to0.05) phenotypic correlatio n was found between the percentage of live embryos after 24-h incubation an d that after 48-h incubation, and also between the percentage of live embry os after 24- and 56-h incubation.