Influence of Dietary Fatty Acids on Fish Sperm Tolerance to Cryopreservation

To meet growing fish demand, aquaculture must develop sustainable, cost-effective, and high-performance fish feed formulations for industry advancement. Plant-based lipids are a viable alternative to forage fish ingredients in finfish diets. However, most plant-derived lipids lack long-chain polyunsaturated fatty acids (LC-PUFA) like EPA and DHA, which are nutritionally essential for fish. This review summarizes recent findings on the nutritional aspects of fish brood stock and sperm quality, emphasizing the effects of fatty acids on reproductive outcomes. Studies indicate that substituting fish oil with plant oils alters the fatty acid profiles in fish tissues and gametes, potentially compromising sperm quality, cryopreservation success, and progeny viability. Sperm membrane lipids, including EPA, DHA, and ARA, are vital for motility and fertilization rates post-thaw. Additionally, cryopreservation has been linked to molecular and epigenetic alterations in sperm, which may negatively affect offspring quality. The role of mRNA and noncoding RNA in regulating sperm function and embryonic development is well known, and thus any damage to these molecules as a consequence of cryopreservation might induce long-term effects on offspring. Proteomic analyses reveal that cryopreservation can lead to significant protein loss in sperm, diminishing their functional and fertilization capabilities. Optimizing cryoprotectant protocols and freezing techniques is crucial to reduce damage, while dietary fatty acids play a key role in preserving sperm quality during cryopreservation stress. Further research with omic technologies is crucial to fully understand sperm tolerance to cryopreservation, which will improve reproductive outcomes and enhance sustainability and quality in aquaculture.