Effect of short-term storage on sperm functional parameters in sex-reversed female mandarin fish (Siniperca chuatsi)

Abstract The sex-reversed female sperm is very important to produce all-females of mandarin fish (Siniperca chuatsi), and the gametes collected in different locations usually needed short-distance transport. Short-term storage is a simple and inexpensive method to preserve sperm, however, the effect of short-term storage on sperm have yet to be studied in sex-reversed female mandarin fish. The purpose of this study was to evaluate the effects of short-term storage on sperm functional parameters in sex-reversed female mandarin fish. Samples of undiluted semen (US), diluted semen 1:2 v/v (DS1), 1:3 v/v (DS2) and 1:4 v/v (DS3) in D-15 diluent were arranged in 50 mL sterile cryogenic tubes and maintained in cold storage at 4 °C in the dark for 5 days. The results showed that sperm functional parameters were significantly affected by storage time, and the sperm motility could be better preserved in diluted groups. Motility of DS1 and DS2 were not significantly different after storage for 1 or 3 days. At day 3 of storage, spermatozoa showed a DNA fragmentation 85% and mitochondrial membrane integrity >80% in all groups, and a fertility >73% in DS1. The percentage of sperm functional parameters decreased significantly at 5 days for all samples of undiluted and diluted semen. However, spermatozoa showed a motility >45%, plasma membrane integrity >75%, mitochondrial membrane integrity >80% and DNA fragmentation 70% at day 5. Except for LIN, the values of VSL, VCL, VAP and ALH in DS1 was significantly higher than that of other groups with storage time of 3–5 days. In conclusion, the results provided new data on sex-reversed female mandarin fish sperm quality with respect to short-term storage evaluated by flow cytometry and confocal laser scanning microscopy, and demonstrated that semen of mandarin fish can be better stored for short term for 5 days in DS1.