Semen cryopreservation in the Salmonidae and in the Northern pike

The present paper summarizes the data on a semen cryopreservation method fo r the Salmonidae (Oncorhynchus mykiss, Salmo trutta f. lacustris, Salvelinu s fontinalis, Salvelinus alpinus, Salmo trutta f. fario, Hucho hucho, Coreg onus lavaretus, Thymallus thymallus) and for the Northern pike (Esox lucius ) published during recent years. It describes (1) methods used for the dete rmination of sperm viability; (2) the protective efficiency of substances s pecifically for protection of internal and external parts of cells and the process of extender development; (3) the freezing, thawing and fertilizatio n conditions; and (4) the tolerable deviations from the freezing protocol f or more easy application. Finally, biomarkers are reported that predict the suitability of semen for cryopreservation and the quality of frozen-thawed semen.