Timing of Mating, Sperm Dynamics: RESULTS(6)

After this date, however, no significant difference was found between the numbers of spermatozoa located in the lower isthmus and of those found in this region after this time, even with the exclusion of the two data points referred to above (Fig. 3). Few spermatozoa were found in the upper isthmus throughout the study period (0.4 X 103 ± 0.5 X 103 spermatozoa per upper isthmus), and none were detected in the ampulla of any mated female (Fig. 3; Table 1). buy cipro

Timing of Ovulation in the Wild

Females that had ovulated were first trapped in the Pow-elltown population on 26 August. All females trapped after the 27th of the month had ovulated (Figs. 2 and 4). The earliest ovulation date deduced from measurements of uterine embryos, however, occurred approximately 1 wk earlier, on 19 August (Fig. 4). Ovulations on this day represented 27% of all ovulations recorded. A peak in ovulations occurred on 20 August, when a further 40% of females had ovulated. The percentage of ovulating females declined after this time (Figs. 2-4), with no ovulations recorded in the Powelltown population after the 27th of the month. Hence, all ovulations recorded in the Powelltown population occurred within an 8-day period (Figs. 2-4).

Total Sperm Number and Epididymal Sperm Distribution in Males Postmating

At the end of the mating season (between 27 August and 3 September), the testes of wild-caught males contained approximately 80.0 X 103 ± 30.0 X 103 spermatozoa per testis. The epididymides at the same time contained approximately 630.0 X 103 ± 28.0 X 103 spermatozoa per epididymis. Epididymal spermatozoa were distributed between segment 3 of the caput epididymidis and segment 12 of the cauda epididymidis. Most spermatozoa, however, were observed in the distal half of the duct, with peak sperm numbers occurring in the distal corpus and proximal cauda regions (segments 9-10) (Fig. 5).
Fig4Timing of Mating
FIG. 4. Dates of ovulation of wild-caught female agile Antechinus from Powelltown, Victoria, Australia.

Fig5Timing of Mating
FIG. 5. Epididymal sperm distribution at the end of the rut (27 August-3 September) in male agile Antechinus from Powelltown, Victoria, Australia. Values are mean ± SD, n = 5.


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