Motility and fertilization ability of sterlet Acipenser ruthenus testicular sperm after cryopreservation.

Sturgeon spermatozoa are immotile in the testis and acquire the potential for motility after contact with urine in Wolffian duct. The present study tested if in vitro incubation of testicular sperm in seminal fluid from Wolffian duct sperm leads to the acquisition of sperm fertilization ability. Sterlet sperm was taken from the testes, matured in vitro and cryopreserved. The fertility and motility of cryopreserved semen were tested. Matured testicular sperm showed freeze–thaw survival rates similar to Wolffian duct sperm, which is commonly used in sturgeon artificial propagation. Matured testicular sperm and Wolffian duct sperm post-thaw motility rate and curvilinear velocity were not significantly different, while duration of matured testicular sperm motility was significantly shorter than that of Wolffian duct sperm. Development rates of embryos obtained with post-thaw matured testicular sperm and Wolffian duct sperm were not significantly different. In vitro maturation of sterlet testicular sperm can potentially be useful in sperm cryobanking. [ABSTRACT FROM AUTHOR]