Artificial spawning of carp Cyprinus carpio L.: differences between the effects on reproduction in females of Polish and Hungarian provenance treatedwith carp pituitary and (D-Ala(6)) GnRH ProNHEt (Kobarelin)

Ovulation was stimulated in carp females of Polish and Hungarian provenance using injections of (D-Ala(6)) GnRH ProNHEt (Kobarelin) (20 mu g kg(-1)) w ith metoclopramide (10 mg kg(-1)) or carp pituitary (3 mg kg(-1)). For esti mating the effects of the substance stimulating ovulation and of the female provenance, analysis of variance was carried out using the least squares m ethod. It was found that the stimulating substance, provenance and interact ion of these factors did not significantly affect the weight of eggs obtain ed. On the other hand, the stimulating substance, provenance and interactio n had a highly significant (P less than or equal to 0.0001) effect on the p ercentages of fertilization and live embryos. Females of Hungarian provenan ce treated with Kobarelin yielded eggs of much better quality but a smaller weight than after the pituitary treatment. In the case of carp females of Polish provenance, a yield of eggs of smaller weight and very poor quality was noted compared with the weight and quality of eggs obtained after hypop hysation.