BLOOD-PLASMA CONCENTRATIONS OF PROGESTERONE, SPERM STORAGE AND SPERM VIABILITY AND FERTILITY IN GOULD WATTLED BAT (CHALINOLOBUS-GOULDII)

The fertility and viability of spermatozoa stored by male and female G ould's wattled bats, Chalinolobus gouldii, was investigated in a capti ve colony of ten bats (three males and seven females). Bats were house d in outdoor flight cages. Plasma progesterone concentrations, measure d using double antibody radioimmunoassay, isolation experiments plus s perm motility and sperm membrane stability tests were used to evaluate the viability and fertility of stored spermatozoa Mean plasma progest erone concentrations were lowest during midwinter (< 0.5 ng ml(-1)) wi th a 20-fold increase recorded in late winter to early spring. During pregnancy, plasma progesterone concentrations increased to about 13 ng ml(-1) and returned to basal values soon after parturition. The resul ts of the plasma progesterone assays and the isolation experiments ind icate that female C. gouldii can store fertile spermatozoa for at leas t 33 days. The investigation of spermatozoa stored by male C. gouldii revealed that 6-7 months after peak spermatogenesis about 60% of the s tored spermatozoa were motile and more than 60% had stable membranes, indicating that the spermatozoa stored by males were viable and likely to be fertile. The results of this study clearly indicate that both m ale and female C. gouldii are capable of storing fertile spermatozoa f or prolonged periods.