Cryopreservation Of Spermatozoa Of The Eriocheir Sinensis H.Milne Edwards

We selected six sperm diluents which had been reported on other animals for our research of sperm In Vitro preservation of Eriocheir sinensis (H Milne Edwards). These diluents were calcium-free sea water I (A), calcium-free sea water II (B), sodium chloride solution (C), crab physiological salt solution (D), potassium chloride solution (E) and glucose solution (F) . Among these diluents, C, E and F were isotonic to sea water . Sperms used in this experiment were obtained from seminal vesicle. Sperm viability and sperm density were critical in determining the preservation effects. Esion dye, a convenient and rapid measuring method for mammal sperm , played a key role in detecting sperm viability . Results showed that sperms preserved in diluents E and F all died two days later, while those preserved in calcium-free sea water (diluent A and B) were still in high viability. Especially in diluent B , sperm viability was as high as 92.19% and sperm density had no significant decline after six days preservation. So, diluent B was optimum for short-term storage of Eriocheir sinensis spermatozoa, and it can be used as a basic storage medium for further study of preservation condition including sperm density, pH and osmosis . Preserved in diluent B, the most ideal sperm density is 10⁶¹0⁷ sperm/mL at 4°C in Ca²⁺FASW. And at pH 7-10, more than 90% sperm viability remained after 15 days storage . Among the 10 different storage solutions whose osmolarity scale were modulated by sodium chloride from 500 to 1000 mOsmol/kg H₂O, the optimum range was 700-850 mOsmol/kg H₂O, in which sperm viability remained above 75% for 15 days . All the results suggested that the optimum osmolarity, sperm density and pH for Eriocheir sinens spermatozoa preservation were 700-850 mOsmol/kg H₂O, 10⁶¹0⁷ sperm/mL, and pH7-10.