EFFECT OF CRYOPRESERVATION AND SHORT-TERM STORAGE OF CHINESE|GIANT SALAMANDER SPERM

Chinese giant salamander (Andrias davidianus) is a rare and endangered endemic amphibian caudata in China.Chinese giant salamander sperm was cryopreserved in liquid nitrogen or stored at 0—4℃ on a short-term basis. Theobjective was to establish reliable technologies for the conservation of this endangered species and for artificial assistedreproduction in Chinese giant salamander farms. The studies showed that the spermatozoa remained motility only 3-5hat the room temperature but 6d at 4℃ and 9d at 0℃. Besides, the viability of spermatozoa precipitous declined afteradding a dilute solution. An improved cryopreservation method for Chinese giant salamander sperm was establishedaccording to the mature technologies for cryopreservation of fish. Cryopreseved sperm was diluted in buffered extenders(pH between 7 and 7.5) containing intracellular (DMSO). The concentration of intracellular cryoprotectants ranged from5% to 25%. In this paper, ten to fifteen percents of the sperm were motile after thawing. The ultrastructures of Chinesegiant salamander sperm before and after cryopreservation were observed by SEM and TEM. Many deformations werefound in the cryopreserved sperm, such as swelling or breaking of the plasma membrane, disappearing of the nuclearenvelope, fracture of the perforatorium and axoneme, degenerating of the undulating membrane and disappearing of themitochondrial ridges. The results indicated that these damages might be the main reasons for the decline of the motilityin the cryopreserved sperm. This study provided an important reference for the establishment of standardized proceduresof the short-term storage and cryopresevation of Chinese giant salamander's sperm as well as the artificial breeding ofChinese giant salamander.