Properties and activities of blood- or seawater-contaminated wild-caught Striped Jewfish (Stereolepis doederleini) sperm

Understanding the effects of environmental factors in sperm qualities will be helpful in the development of optimal artificial reproduction methods and contributes towards the knowledge base of better short- and long-term fish semen preservation conditions The objectives of this study were to determine properties and activities of wild-caught striped jewfish Stereolepis doederleini sperm contaminated with blood or seawater and compare them with data reported in the literature on other freshwater and marine fish species, for effective short- and long-term storage of fish semen. Overall, we observed that the sodium, chloride, glucose, total protein concentrations of normal sperm were not significantly different from blood- or seawater-contaminated sperm. The salinity and osmolality concentration of sperm contaminated with blood were lower than sperm contaminated with seawater and were not significantly different from normal sperm. In addition, the spermatozoa motility (SM) and duration of spermatozoa motility (DSM) in blood-contaminated sperm were higher than seawater-contaminated sperm and also not significantly different from normal sperm. The best condition for SM and DSM in normal sperm was dilution rate of 1:50. Sperm was immotile in distilled water, and cationic factors were shown to stimulate the initiation of spermatozoa activation. The maximum SM and DSM were observed in solution containing 0.4M NaCl, 0.6M KCl, 0.6M CaCl2 and 0.4M MgCl2. This study provides some basic and important knowledge about striped jewfish sperm sensitivity to a cationic condition. In this regard, Na+ is the major inhibitory factor of spermatozoa motility in this fish species.