Common carp (Cyprinus carpio) sperm is routinely cooled to 4 °C after collection, even during short-term storage. This procedure is standard practice in hatcheries when sperm is collected in advance of the spawning of females. Although fluctuating fertilization success rates were traditionally attributed mainly to egg quality, it has been shown that the stability of the sperm itself also plays a significant role. Carp sperm is relatively sensitive and shows a marked decline in quality parameters after just a few hours of storage.
This study evaluated different methods of sperm storage during the period between collection and fertilization, aiming to determine whether it is necessary to dilute sperm with artificial seminal plasma and store it in a cooled state when used within 6 hours of collection. Sperm was stored either undiluted or diluted with artificial seminal plasma, and either on ice or at room temperature. The results showed that sperm diluted with artificial seminal plasma better preserves sperm quality, especially when stored on ice. This method also resulted in higher fertilization and subsequent hatching success rates compared to undiluted sperm. The study confirms that the most suitable method is to dilute sperm with artificial seminal plasma in a 1:1 ratio and subsequently store it on ice. For optimal fertilization results, the diluted sperm must be briefly equilibrated to approximately 20 °C before use.
The study clearly demonstrated that carp sperm cannot be reliably stored, even for several hours, without the use of artificial seminal plasma and cooling, as both sperm quality and reproductive potential significantly decline under such conditions.
More detailed information can be found in the original scientific article:
Ma, Z., Zhang, S., Hossain, Md.S., Mahammadi, Y., Alavi, S.M.H., Havlíková, Z., Dzyuba, V., Shazada, N.E., Gela, D., Linhart, O., 2026. Management of common carp (Cyprinus carpio L.) milt storage for breeding programs: The role of extender and temperature. Aquaculture Reports 48: 103602.
