Standardized Cryopreservation Protocols for European Perch (Perca fluviatilis) and Pikeperch (Sander lucioperca) Semen Enabling Hatchery-Scale Fertilization.

Cryopreservation of fish semen ensures the year-round availability of gametes from species with seasonal spawning, supports genetic resource banking, and underpins selective breeding programs. However, percid species such as European perch and pikeperch pose specific challenges, notably the spontaneous activation of sperm motility in seminal plasma, which can reduce sperm motility reserves during cryopreservation. Building on systematic studies, here we present standardized protocols for semen collection, sperm quality evaluation, extender preparation, freezing, thawing, and post-thaw handling. These protocols support reliable commercial cryobanking and enable consistent, hatchery-scale fertilization in percid aquaculture.