SEMEN PARAMETERS AND ELECTRON-MICROSCOPE OBSERVATIONS OF SPERMATOZOA OF THE RED WOLF, CANIS-RUFUS

Semen parameters were evaluated on ejaculates of a captive population of red wolves (Canis rufus) sampled over two consecutive mating season s. A total of 31 samples from 15 animals yielded mean sperm motility o f 69.6 +/- 19.4%, mean sperm density of 131 +/- 124 x 10(6) ml(-1), me an total number of spermatozoa of 470 +/- 465 x 10(6) and mean percent age morphologically abnormal spermatozoa of 35 +/- 11.8%. Restricting the data to animals sampled three times or more or limiting the sample s to proven breeders resulted in statistically non-significant differe nces in these numbers (P < 0.05). When compared with data from other c anines the seminal parameters of red wolves are at the lower extremes of the range. In particular the proportion of morphologically abnormal spermatozoa (35%) is approximately twice that seen in other canine sp ecies. Light microscopic analysis of abnormal forms revealed that almo st half (45%) were bent defects, another 40% were secondary defects (c oiled, detached and immature) and 15% were primary defects. Electron m icroscopy confirmed the presence of substantial numbers of morphologic ally abnormal forms including double-headed and double-flagellar cells , bent or kinked forms especially in the neck region, acrosomal abnorm alities and bizarre spermatids. Approximately one-third of the samples also showed the presence of white blood cells, in some cases demonstr ating sperm phagocytosis (spermophagy). These results are consistent w ith the concept of declining sperm parameters associated with restrict ed. gene pools in numerically limited populations. However, alternativ e explanations are also explored.