First insight into the insemination-induced spawning method in pikeperch (Sander lucioperca) without the presence of a male

The insemination-based propagation method, in which sperm is inseminated and stored in the ovary until ovulation, may offer a unique approach to induced spawning in externally fertilizing, nest-spawning fish species. This study evaluated the effectiveness and limitations of this technique in pikeperch ( Sander lucioperca ) propagation under artificial conditions in the absence of males. In the experiment, ten female pikeperch were hormonally induced with carp pituitary extract and inseminated via catheter. Oocyte maturation was monitored by serial biopsies, and spawning was facilitated using artificial substrates. Results showed that eight out of ten experimental females ovulated spontaneously, but exhibited considerable variation in the timing of egg release (83–100 h post-hormone administration). Fertilisation rates ranged widely (0–83.9 %), with no clear correlation to the latency time of sperm in the ovary. The absence of males led to atypical egg dispersion and could have contributed to inadequate ovulation success as well. While insemination-induced spawning can enable reproduction without males and may increase genetic diversity by using multiple sperm samples, its efficiency is constrained by species-specific sperm viability and the absence of natural spawning behavior. Further optimisation is necessary for broader application in pikeperch aquaculture. • Ten females were inseminated using pooled sperm originating from four males. • Spontaneous egg release was observed upon ovulation without the presence of males. • Individual variations in fertilization rate are not related to sperm storage time.