Several studies have suggested that the caudal neurosecretory system could act on fish reproduction. The aim of this study was to compare the effect of urophysial extract (UE) and carp pituitary homogenate (CPH) on the induction of spawning in Hoplias malabaricus, Rhamdia quelen and Cyprinus carpio. The amount of UE injected was 1.0 to 3.0mg/kg L.W. (single dose) and CPH 3.0 to 4.0mg/kg L.W. (two doses). The application of UE had no effect on spawning induction, while CPH improved spawning of all studied species.
fish-culture; induced reproduction; urophysis; pituitary; spawning
